## Guide to the Secure Configuration of Red Hat Enterprise Linux 8

> with profile Red Hat Corporate Profile for Certified Cloud Providers (RH CCP)
> This profile contains the minimum security relevant configuration settings recommended by Red Hat, Inc for Red Hat Enterprise Linux 8 instances deployed by Red Hat Certified Cloud Providers.

The SCAP Security Guide Project
https://www.open-scap.org/security-policies/scap-security-guide
This guide presents a catalog of security-relevant configuration settings for Red Hat Enterprise Linux 8. It is a rendering of content structured in the eXtensible Configuration Checklist Description Format (XCCDF) in order to support security automation. The SCAP content is is available in the `scap-security-guide` package which is developed at https://www.open-scap.org/security-policies/scap-security-guide.
Providing system administrators with such guidance informs them how to securely configure systems under their control in a variety of network roles. Policy makers and baseline creators can use this catalog of settings, with its associated references to higher-level security control catalogs, in order to assist them in security baseline creation. This guide is a catalog, not a checklist, and satisfaction of every item is not likely to be possible or sensible in many operational scenarios. However, the XCCDF format enables granular selection and adjustment of settings, and their association with OVAL and OCIL content provides an automated checking capability. Transformations of this document, and its associated automated checking content, are capable of providing baselines that meet a diverse set of policy objectives. Some example XCCDF Profiles, which are selections of items that form checklists and can be used as baselines, are available with this guide. They can be processed, in an automated fashion, with tools that support the Security Content Automation Protocol (SCAP). The DISA STIG, which provides required settings for US Department of Defense systems, is one example of a baseline created from this guidance.

This benchmark is a direct port of a SCAP Security Guide benchmark developed for Red Hat Enterprise Linux. It has been modified through an automated process to remove specific dependencies on Red Hat Enterprise Linux and to function with CentOS. The result is a generally useful SCAP Security Guide benchmark with the following caveats:

- CentOS is not an exact copy of Red Hat Enterprise Linux. There may be configuration differences that produce false positives and/or false negatives. If this occurs please file a bug report.
- CentOS has its own build system, compiler options, patchsets, and is a community supported, non-commercial operating system. CentOS does not inherit certifications or evaluations from Red Hat Enterprise Linux. As such, some configuration rules (such as those requiring FIPS 140-2 encryption) will continue to fail on CentOS.

Members of the CentOS community are invited to participate in OpenSCAP and SCAP Security Guide development. Bug reports and patches can be sent to GitHub: https://github.com/ComplianceAsCode/content. The mailing list is at https://fedorahosted.org/mailman/listinfo/scap-security-guide.

Do not attempt to implement any of the settings in this guide without first testing them in a non-operational environment. The creators of this guidance assume no responsibility whatsoever for its use by other parties, and makes no guarantees, expressed or implied, about its quality, reliability, or any other characteristic.

## Profile Information

Profile Title | Red Hat Corporate Profile for Certified Cloud Providers (RH CCP)
Profile ID | xccdf_org.ssgproject.content_profile_rht-ccp

#### CPE Platforms

- cpe:/o:redhat:enterprise_linux:8.0
- cpe:/o:redhat:enterprise_linux:8.1
- cpe:/o:redhat:enterprise_linux:8.10
- cpe:/o:redhat:enterprise_linux:8.2
- cpe:/o:redhat:enterprise_linux:8.3
- cpe:/o:redhat:enterprise_linux:8.4
- cpe:/o:redhat:enterprise_linux:8.5
- cpe:/o:redhat:enterprise_linux:8.6
- cpe:/o:redhat:enterprise_linux:8.7
- cpe:/o:redhat:enterprise_linux:8.8
- cpe:/o:redhat:enterprise_linux:8.9
- cpe:/o:redhat:enterprise_linux:8
- cpe:/o:centos:centos:8

## Revision History

Current version: 0.1.71

- draft (as of 2023-12-16)

## Table of Contents

1. System Settings
   1. Installing and Maintaining Software
   2. Account and Access Control
   3. System Accounting with auditd
   4. GRUB2 bootloader configuration
   5. Network Configuration and Firewalls
   6. File Permissions and Masks
   7. SELinux
2. Services
   1. Base Services
   2. Obsolete Services
   3. SSH Server

## Checklist

Group Guide to the Secure Configuration of Red Hat Enterprise Linux 8 Group contains 39 groups and 71 rules
Group System Settings Group contains 32 groups and 58 rules
[ref] Contains rules that check correct system settings.
Group Installing and Maintaining Software Group contains 6 groups and 11 rules
[ref] The following sections contain information on security-relevant choices during the initial operating system installation process and the setup of software updates.
Group System and Software Integrity Group contains 3 groups and 3 rules

[ref] System and software integrity can be gained by installing antivirus, increasing system encryption strength with FIPS, verifying installed software, enabling SELinux, installing an Intrusion Prevention System, etc. However, installing or enabling integrity checking tools cannot prevent intrusions, but they can detect that an intrusion may have occurred. Requirements for integrity checking may be highly dependent on the environment in which the system will be used. Snapshot-based approaches such as AIDE may induce considerable overhead in the presence of frequent software updates.

Group Software Integrity Checking Group contains 1 group and 1 rule

[ref] Both the AIDE (Advanced Intrusion Detection Environment) software and the RPM package management system provide mechanisms for verifying the integrity of installed software. AIDE uses snapshots of file metadata (such as hashes) and compares these to current system files in order to detect changes.
The RPM package management system can conduct integrity checks by comparing information in its metadata database with files installed on the system.

Group Verify Integrity with AIDE Group contains 1 rule
[ref] AIDE conducts integrity checks by comparing information about files with previously-gathered information. Ideally, the AIDE database is created immediately after initial system configuration, and then again after any software update. AIDE is highly configurable, with further configuration information located in `/usr/share/doc/aide-VERSION`.

#### Rule Install AIDE [ref]

The `aide` package can be installed with the following command:

    $ sudo yum install aide

Rationale: | The AIDE package must be installed if it is to be available for integrity checking.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_package_aide_installed

Identifiers and References

References: BP28(R51), 1, 11, 12, 13, 14, 15, 16, 2, 3, 5, 7, 8, 9, 5.10.1.3, APO01.06, BAI01.06, BAI02.01, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS04.07, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.02, DSS06.06, CCI-002696, CCI-002699, CCI-001744, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 4.1, SR 6.2, SR 7.6, 1034, 1288, 1341, 1417, A.11.2.4, A.12.1.2, A.12.2.1, A.12.4.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.14.2.7, A.15.2.1, A.8.2.3, CM-6(a), DE.CM-1, DE.CM-7, PR.DS-1, PR.DS-6, PR.DS-8, PR.IP-1, PR.IP-3, Req-11.5, 11.5.2, SRG-OS-000445-GPOS-00199, 1.3.1, SV-251710r880730_rule

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable

    # Remediation is applicable only in certain platforms
    if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

    if ! rpm -q --quiet "aide" ; then
        yum install -y "aide"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Anaconda snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable

    package --add=aide

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable

    - name: Ensure aide is installed
      package:
        name: aide
        state: present
      when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - CJIS-5.10.1.3
      - DISA-STIG-RHEL-08-010359
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-11.5
      - PCI-DSSv4-11.5.2
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - package_aide_installed

Remediation OSBuild Blueprint snippet ⇲

    [[packages]]
    name = "aide"
    version = "*"

Remediation Puppet snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable

    include install_aide

    class install_aide {
      package { 'aide':
        ensure => 'installed',
      }
    }

Group System Cryptographic Policies Group contains 2 rules

[ref] Linux has the capability to centrally configure cryptographic polices. The command `update-crypto-policies` is used to set the policy applicable for the various cryptographic back-ends, such as SSL/TLS libraries. The configured cryptographic policies will be the default policy used by these backends unless the application user configures them otherwise. When the system has been configured to use the centralized cryptographic policies, the administrator is assured that any application that utilizes the supported backends will follow a policy that adheres to the configured profile. Currently the supported backends are:

- GnuTLS library
- OpenSSL library
- NSS library
- OpenJDK
- Libkrb5
- BIND
- OpenSSH

Applications and languages which rely on any of these backends will follow the system policies as well. Examples are apache httpd, nginx, php, and others.

#### Rule Configure System Cryptography Policy [ref]

To configure the system cryptography policy to use ciphers only from the `FIPS` policy, run the following command:

    $ sudo update-crypto-policies --set FIPS

The rule checks if settings for selected crypto policy are configured as expected. Configuration files in the `/etc/crypto-policies/back-ends` are either symlinks to correct files provided by Crypto-policies package or they are regular files in case crypto policy customizations are applied. Crypto policies may be customized by crypto policy modules, in which case it is delimited from the base policy using a colon.
Warning: The system needs to be rebooted for these changes to take effect.
Warning: System Crypto Modules must be provided by a vendor that undergoes FIPS-140 certifications. FIPS-140 is applicable to all Federal agencies that use cryptographic-based security systems to protect sensitive information in computer and telecommunication systems (including voice systems) as defined in Section 5131 of the Information Technology Management Reform Act of 1996, Public Law 104-106. This standard shall be used in designing and implementing cryptographic modules that Federal departments and agencies operate or are operated for them under contract. See https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.140-2.pdf To meet this, the system has to have cryptographic software provided by a vendor that has undergone this certification. This means providing documentation, test results, design information, and independent third party review by an accredited lab. While open source software is capable of meeting this, it does not meet FIPS-140 unless the vendor submits to this process.

Rationale: | Centralized cryptographic policies simplify applying secure ciphers across an operating system and the applications that run on that operating system. Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data.
Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_configure_crypto_policy

Identifiers and References

References: 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.312(e)(1), 164.312(e)(2)(ii), 1446, CIP-003-8 R4.2, CIP-007-3 R5.1, CIP-007-3 R7.1, AC-17(a), AC-17(2), CM-6(a), MA-4(6), SC-13, SC-12(2), SC-12(3), FCS_COP.1(1), FCS_COP.1(2), FCS_COP.1(3), FCS_COP.1(4), FCS_CKM.1, FCS_CKM.2, FCS_TLSC_EXT.1, 2.2.7, SRG-OS-000396-GPOS-00176, SRG-OS-000393-GPOS-00173, SRG-OS-000394-GPOS-00174, 1.10, 1.11, SV-230223r928585_rule

Remediation Shell script ⇲

    var_system_crypto_policy='FIPS'

    stderr_of_call=$(update-crypto-policies --set ${var_system_crypto_policy} 2>&1 > /dev/null)
    rc=$?

    if test "$rc" = 127; then
    	echo "$stderr_of_call" >&2
    	echo "Make sure that the script is installed on the remediated system." >&2
    	echo "See output of the 'dnf provides update-crypto-policies' command" >&2
    	echo "to see what package to (re)install" >&2

    	false  # end with an error code
    elif test "$rc" != 0; then
    	echo "Error invoking the update-crypto-policies script: $stderr_of_call" >&2
    	false  # end with an error code
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    - name: XCCDF Value var_system_crypto_policy # promote to variable
      set_fact:
        var_system_crypto_policy: !!str FIPS
      tags:
        - always

    - name: Configure System Cryptography Policy
      lineinfile:
        path: /etc/crypto-policies/config
        regexp: ^(?!#)(\S+)$
        line: '{{ var_system_crypto_policy }}'
        create: true
      tags:
      - DISA-STIG-RHEL-08-010020
      - NIST-800-53-AC-17(2)
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-MA-4(6)
      - NIST-800-53-SC-12(2)
      - NIST-800-53-SC-12(3)
      - NIST-800-53-SC-13
      - PCI-DSSv4-2.2.7
      - configure_crypto_policy
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy

    - name: Verify that Crypto Policy is Set (runtime)
      command: /usr/bin/update-crypto-policies --set {{ var_system_crypto_policy }}
      tags:
      - DISA-STIG-RHEL-08-010020
      - NIST-800-53-AC-17(2)
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-MA-4(6)
      - NIST-800-53-SC-12(2)
      - NIST-800-53-SC-12(3)
      - NIST-800-53-SC-13
      - PCI-DSSv4-2.2.7
      - configure_crypto_policy
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy

Remediation Kubernetes snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict

    ---
    apiVersion: machineconfiguration.openshift.io/v1
    kind: MachineConfig
    spec:
      config:
        ignition:
          version: 3.1.0
        systemd:
          units:
            - name: configure-crypto-policy.service
              enabled: true
              contents: |
                [Unit]
                Before=kubelet.service
                [Service]
                Type=oneshot
                ExecStart=update-crypto-policies --set {{.var_system_crypto_policy}}
                RemainAfterExit=yes
                [Install]
                WantedBy=multi-user.target

#### Rule Configure SSH to use System Crypto Policy [ref]

Crypto Policies provide a centralized control over crypto algorithms usage of many packages. SSH is supported by crypto policy, but the SSH configuration may be set up to ignore it. To check that Crypto Policies settings are configured correctly, ensure that the `CRYPTO_POLICY` variable is either commented or not set at all in the `/etc/sysconfig/sshd`.
Rationale: | Overriding the system crypto policy makes the behavior of the SSH service violate expectations, and makes system configuration more fragmented.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_configure_ssh_crypto_policy
Identifiers and References | References: CCI-001453, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.312(e)(1), 164.312(e)(2)(ii), CIP-003-8 R4.2, CIP-007-3 R5.1, CIP-007-3 R7.1, AC-17(a), AC-17(2), CM-6(a), MA-4(6), SC-13, FCS_SSH_EXT.1, FCS_SSHS_EXT.1, FCS_SSHC_EXT.1, Req-2.2, 2.2.7, SRG-OS-000250-GPOS-00093, 5.2.14, SV-244526r877394_rule

Remediation Shell script ⇲

    SSH_CONF="/etc/sysconfig/sshd"

    sed -i "/^\s*CRYPTO_POLICY.*$/Id" $SSH_CONF

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable

    - name: Configure SSH to use System Crypto Policy
      lineinfile:
        dest: /etc/sysconfig/sshd
        state: absent
        regexp: ^(?i)\s*CRYPTO_POLICY.*$
      tags:
      - DISA-STIG-RHEL-08-010287
      - NIST-800-53-AC-17(2)
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-MA-4(6)
      - NIST-800-53-SC-13
      - PCI-DSS-Req-2.2
      - PCI-DSSv4-2.2.7
      - configure_ssh_crypto_policy
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required

Group Disk Partitioning Group contains 4 rules

[ref] To ensure separation and protection of data, there are top-level system directories which should be placed on their own physical partition or logical volume. The installer's default partitioning scheme creates separate logical volumes for `/`, `/boot`, and `swap`.

- If starting with any of the default layouts, check the box to \"Review and modify partitioning.\" This allows for the easy creation of additional logical volumes inside the volume group already created, though it may require making `/`'s logical volume smaller to create space. In general, using logical volumes is preferable to using partitions because they can be more easily adjusted later.
- If creating a custom layout, create the partitions mentioned in the previous paragraph (which the installer will require anyway), as well as separate ones described in the following sections.

If a system has already been installed, and the default partitioning scheme was used, it is possible but nontrivial to modify it to create separate logical volumes for the directories listed above. The Logical Volume Manager (LVM) makes this possible. See the LVM HOWTO at http://tldp.org/HOWTO/LVM-HOWTO/ for more detailed information on LVM.

#### Rule Ensure /tmp Located On Separate Partition [ref]

The `/tmp` directory is a world-writable directory used for temporary file storage. Ensure it has its own partition or logical volume at installation time, or migrate it using LVM.
Rationale: | The `/tmp` partition is used as temporary storage by many programs. Placing `/tmp` in its own partition enables the setting of more restrictive mount options, which can help protect programs which use it.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_partition_for_tmp
Identifiers and References | References: BP28(R12), 12, 15, 8, APO13.01, DSS05.02, CCI-000366, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.13.1.1, A.13.2.1, A.14.1.3, CM-6(a), SC-5(2), PR.PT-4, SRG-OS-000480-GPOS-00227, 1.1.2.1, SV-230295r627750_rule

Remediation Anaconda snippet ⇲

Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable

    part /tmp

Remediation OSBuild Blueprint snippet ⇲

    [[customizations.filesystem]]
    mountpoint = "/tmp"
    size = 1073741824

#### Rule Ensure /var Located On Separate Partition [ref]

The `/var` directory is used by daemons and other system services to store frequently-changing data. Ensure that `/var` has its own partition or logical volume at installation time, or migrate it using LVM.
Rationale: | Ensuring that `/var` is mounted on its own partition enables the setting of more restrictive mount options. This helps protect system services such as daemons or other programs which use it. It is not uncommon for the `/var` directory to contain world-writable directories installed by other software packages.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_partition_for_var
Identifiers and References | References: BP28(R12), 12, 15, 8, APO13.01, DSS05.02, CCI-000366, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.13.1.1, A.13.2.1, A.14.1.3, CM-6(a), SC-5(2), PR.PT-4, SRG-OS-000480-GPOS-00227, 1.1.3.1, SV-230292r902718_rule

Remediation Anaconda snippet ⇲

Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable

    part /var

Remediation OSBuild Blueprint snippet ⇲

    [[customizations.filesystem]]
    mountpoint = "/var"
    size = 3221225472

#### Rule Ensure /var/log Located On Separate Partition [ref]

System logs are stored in the `/var/log` directory. Ensure that `/var/log` has its own partition or logical volume at installation time, or migrate it using LVM.
Rationale: | Placing `/var/log` in its own partition enables better separation between log files and other files in `/var/`.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_partition_for_var_log

Identifiers and References

References: BP28(R12), BP28(R47), 1, 12, 14, 15, 16, 3, 5, 6, 8, APO11.04, APO13.01, BAI03.05, DSS05.02, DSS05.04, DSS05.07, MEA02.01, CCI-000366, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, CIP-007-3 R6.5, CM-6(a), AU-4, SC-5(2), PR.PT-1, PR.PT-4, SRG-OS-000480-GPOS-00227, 1.1.5.1, SV-230293r902720_rule

Remediation Anaconda snippet ⇲

Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable

    part /var/log

Remediation OSBuild Blueprint snippet ⇲

    [[customizations.filesystem]]
    mountpoint = "/var/log"
    size = 5368709120

#### Rule Ensure /var/log/audit Located On Separate Partition [ref]

Audit logs are stored in the `/var/log/audit` directory. Ensure that `/var/log/audit` has its own partition or logical volume at installation time, or migrate it using LVM. Make absolutely certain that it is large enough to store all audit logs that will be created by the auditing daemon.
Rationale: | Placing `/var/log/audit` in its own partition enables better separation between audit files and other files, and helps ensure that auditing cannot be halted due to the partition running out of space.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_partition_for_var_log_audit

Identifiers and References

References: BP28(R43), 1, 12, 13, 14, 15, 16, 2, 3, 5, 6, 8, APO11.04, APO13.01, BAI03.05, BAI04.04, DSS05.02, DSS05.04, DSS05.07, MEA02.01, CCI-000366, CCI-001849, 164.312(a)(2)(ii), 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.2, SR 7.6, A.12.1.3, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.17.2.1, CIP-007-3 R6.5, CM-6(a), AU-4, SC-5(2), PR.DS-4, PR.PT-1, PR.PT-4, FMT_SMF_EXT.1, SRG-OS-000341-GPOS-00132, SRG-OS-000480-GPOS-00227, SRG-APP-000357-CTR-000800, 1.1.6.1, SV-230294r627750_rule

Remediation Anaconda snippet ⇲

Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable

    part /var/log/audit

Remediation OSBuild Blueprint snippet ⇲

    [[customizations.filesystem]]
    mountpoint = "/var/log/audit"
    size = 10737418240

Group Updating Software Group contains 4 rules

[ref] The `yum` command line tool is used to install and update software packages. The system also provides a graphical software update tool in the System menu, in the Administration submenu, called Software Update.
Red Hat Enterprise Linux 8 systems contain an installed software catalog called the RPM database, which records metadata of installed packages. Consistently using `yum` or the graphical Software Update for all software installation allows for insight into the current inventory of installed software on the system.

#### Rule Ensure gpgcheck Enabled In Main yum Configuration [ref]

The `gpgcheck` option controls whether RPM packages' signatures are always checked prior to installation. To configure yum to check package signatures before installing them, ensure the following line appears in `/etc/yum.conf` in the `[main]` section:

    gpgcheck=1

Rationale:

Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor.
Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization.
Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. Certificates used to verify the software must be from an approved Certificate Authority (CA).

Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_ensure_gpgcheck_globally_activated

Identifiers and References

References: BP28(R15), 11, 2, 3, 9, 5.10.4.1, APO01.06, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS06.02, 3.4.8, CCI-001749, 164.308(a)(1)(ii)(D), 164.312(b), 164.312(c)(1), 164.312(c)(2), 164.312(e)(2)(i), 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 7.6, A.11.2.4, A.12.1.2, A.12.2.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, CM-5(3), SI-7, SC-12, SC-12(3), CM-6(a), SA-12, SA-12(10), CM-11(a), CM-11(b), PR.DS-6, PR.DS-8, PR.IP-1, FPT_TUD_EXT.1, FPT_TUD_EXT.2, Req-6.2, 6.3.3, SRG-OS-000366-GPOS-00153, 1.2.3, SV-230264r880711_rule

Remediation Shell script ⇲

    # Remediation is applicable only in certain platforms
    if rpm --quiet -q yum; then

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^gpgcheck")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "1"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^gpgcheck\\>" "/etc/yum.conf"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^gpgcheck\\>.*/$escaped_formatted_output/gi" "/etc/yum.conf"
    else
        if [[ -s "/etc/yum.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/yum.conf" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/yum.conf"
        fi
        cce=""
        printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/yum.conf" >> "/etc/yum.conf"
        printf '%s\n' "$formatted_output" >> "/etc/yum.conf"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | configure

    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.10.4.1
      - DISA-STIG-RHEL-08-010370
      - NIST-800-171-3.4.8
      - NIST-800-53-CM-11(a)
      - NIST-800-53-CM-11(b)
      - NIST-800-53-CM-5(3)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SA-12
      - NIST-800-53-SA-12(10)
      - NIST-800-53-SC-12
      - NIST-800-53-SC-12(3)
      - NIST-800-53-SI-7
      - PCI-DSS-Req-6.2
      - PCI-DSSv4-6.3.3
      - configure_strategy
      - ensure_gpgcheck_globally_activated
      - high_severity
      - low_complexity
      - medium_disruption
      - no_reboot_needed

    - name: Ensure GPG check is globally activated
      ini_file:
        dest: /etc/yum.conf
        section: main
        option: gpgcheck
        value: 1
        no_extra_spaces: true
        create: false
      when: '"yum" in ansible_facts.packages'
      tags:
      - CJIS-5.10.4.1
      - DISA-STIG-RHEL-08-010370
      - NIST-800-171-3.4.8
      - NIST-800-53-CM-11(a)
      - NIST-800-53-CM-11(b)
      - NIST-800-53-CM-5(3)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SA-12
      - NIST-800-53-SA-12(10)
      - NIST-800-53-SC-12
      - NIST-800-53-SC-12(3)
      - NIST-800-53-SI-7
      - PCI-DSS-Req-6.2
      - PCI-DSSv4-6.3.3
      - configure_strategy
      - ensure_gpgcheck_globally_activated
      - high_severity
      - low_complexity
      - medium_disruption
      - no_reboot_needed

#### Rule Ensure gpgcheck Enabled for All yum Package Repositories [ref]

To ensure signature checking is not disabled for any repos, remove any lines from files in `/etc/yum.repos.d` of the form:

    gpgcheck=0

Rationale:

Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. Certificates used to verify the software must be from an approved Certificate Authority (CA)."

Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_ensure_gpgcheck_never_disabled

Identifiers and References

References: BP28(R15), 11, 2, 3, 9, 5.10.4.1, APO01.06, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS06.02, 3.4.8, CCI-001749, 164.308(a)(1)(ii)(D), 164.312(b), 164.312(c)(1), 164.312(c)(2), 164.312(e)(2)(i), 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 7.6, A.11.2.4, A.12.1.2, A.12.2.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, CM-5(3), SI-7, SC-12, SC-12(3), CM-6(a), SA-12, SA-12(10), CM-11(a), CM-11(b), PR.DS-6, PR.DS-8, PR.IP-1, FPT_TUD_EXT.1, FPT_TUD_EXT.2, Req-6.2, 6.3.3, SRG-OS-000366-GPOS-00153, SV-230264r880711_rule

Remediation Shell script ⇲

    sed -i 's/gpgcheck\s*=.*/gpgcheck=1/g' /etc/yum.repos.d/*

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | enable

    - name: Grep for yum repo section names
      shell: |
        set -o pipefail
        grep -HEr '^\[.+\]' -r /etc/yum.repos.d/
      register: repo_grep_results
      failed_when: repo_grep_results.rc not in [0, 1]
      changed_when: false
      tags:
      - CJIS-5.10.4.1
      - DISA-STIG-RHEL-08-010370
      - NIST-800-171-3.4.8
      - NIST-800-53-CM-11(a)
      - NIST-800-53-CM-11(b)
      - NIST-800-53-CM-5(3)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SA-12
      - NIST-800-53-SA-12(10)
      - NIST-800-53-SC-12
      - NIST-800-53-SC-12(3)
      - NIST-800-53-SI-7
      - PCI-DSS-Req-6.2
      - PCI-DSSv4-6.3.3
      - enable_strategy
      - ensure_gpgcheck_never_disabled
      - high_severity
      - low_complexity
      - medium_disruption
      - no_reboot_needed

    - name: Set gpgcheck=1 for each yum repo
      ini_file:
        path: '{{ item[0] }}'
        section: '{{ item[1] }}'
        option: gpgcheck
        value: '1'
        no_extra_spaces: true
      loop: '{{ repo_grep_results.stdout | regex_findall( ''(.+\.repo):\[(.+)\]\n?'' )
        }}'
      tags:
      - CJIS-5.10.4.1
      - DISA-STIG-RHEL-08-010370
      - NIST-800-171-3.4.8
      - NIST-800-53-CM-11(a)
      - NIST-800-53-CM-11(b)
      - NIST-800-53-CM-5(3)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SA-12
      - NIST-800-53-SA-12(10)
      - NIST-800-53-SC-12
      - NIST-800-53-SC-12(3)
      - NIST-800-53-SI-7
      - PCI-DSS-Req-6.2
      - PCI-DSSv4-6.3.3
      - enable_strategy
      - ensure_gpgcheck_never_disabled
      - high_severity
      - low_complexity
      - medium_disruption
      - no_reboot_needed

#### Rule Ensure Red Hat GPG Key Installed [ref]

To ensure the system can cryptographically verify base software packages come from Red Hat (and to connect to the Red Hat Network to receive them), the Red Hat GPG key must properly be installed. To install the Red Hat GPG key, run:

    $ sudo subscription-manager register

If the system is not connected to the Internet or an RHN Satellite, then install the Red Hat GPG key from trusted media such as the Red Hat installation CD-ROM or DVD. Assuming the disc is mounted in `/media/cdrom`, use the following command as the root user to import it into the keyring:

    $ sudo rpm --import /media/cdrom/RPM-GPG-KEY

Alternatively, the key may be pre-loaded during the RHEL installation. In such cases, the key can be installed by running the following command:

    sudo rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release

Rationale: | Changes to software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. The Red Hat GPG key is necessary to cryptographically verify packages are from Red Hat.
Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_ensure_redhat_gpgkey_installed

Identifiers and References

References: BP28(R15), 11, 2, 3, 9, 5.10.4.1, APO01.06, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS06.02, 3.4.8, CCI-001749, 164.308(a)(1)(ii)(D), 164.312(b), 164.312(c)(1), 164.312(c)(2), 164.312(e)(2)(i), 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 7.6, A.11.2.4, A.12.1.2, A.12.2.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, CIP-003-8 R4.2, CIP-003-8 R6, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-5(3), SI-7, SC-12, SC-12(3), CM-6(a), PR.DS-6, PR.DS-8, PR.IP-1, FPT_TUD_EXT.1, FPT_TUD_EXT.2, Req-6.2, 6.3.3, SRG-OS-000366-GPOS-00153, 1.2.2, SV-256973r902752_rule

Remediation Shell script ⇲

    # The two fingerprints below are retrieved from https://access.redhat.com/security/team/key
    readonly REDHAT_RELEASE_FINGERPRINT="567E347AD0044ADE55BA8A5F199E2F91FD431D51"
    readonly REDHAT_AUXILIARY_FINGERPRINT="6A6AA7C97C8890AEC6AEBFE2F76F66C3D4082792"

    # Location of the key we would like to import (once it's integrity verified)
    readonly REDHAT_RELEASE_KEY="/etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release"

    RPM_GPG_DIR_PERMS=$(stat -c %a "$(dirname "$REDHAT_RELEASE_KEY")")

    # Verify /etc/pki/rpm-gpg directory permissions are safe
    if [ "${RPM_GPG_DIR_PERMS}" -le "755" ]
    then
      # If they are safe, try to obtain fingerprints from the key file
      # (to ensure there won't be e.g. CRC error).

      readarray -t GPG_OUT < <(gpg --show-keys --with-fingerprint --with-colons "$REDHAT_RELEASE_KEY" | grep -A1 "^pub" | grep "^fpr" | cut -d ":" -f 10)

      GPG_RESULT=$?
      # No CRC error, safe to proceed
      if [ "${GPG_RESULT}" -eq "0" ]
      then
        echo "${GPG_OUT[*]}" | grep -vE "${REDHAT_RELEASE_FINGERPRINT}|${REDHAT_AUXILIARY_FINGERPRINT}" || {
          # If $REDHAT_RELEASE_KEY file doesn't contain any keys with unknown fingerprint, import it
          rpm --import "${REDHAT_RELEASE_KEY}"
        }
      fi
    fi

Remediation Ansible snippet ⇲

Complexity: | medium
Disruption: | medium
Reboot: | false
Strategy: | restrict

    - name: Read permission of GPG key directory
      stat:
        path: /etc/pki/rpm-gpg/
      register: gpg_key_directory_permission
      check_mode: false
      tags:
      - CJIS-5.10.4.1
      - DISA-STIG-RHEL-08-010019
      - NIST-800-171-3.4.8
      - NIST-800-53-CM-5(3)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-12
      - NIST-800-53-SC-12(3)
      - NIST-800-53-SI-7
      - PCI-DSS-Req-6.2
      - PCI-DSSv4-6.3.3
      - ensure_redhat_gpgkey_installed
      - high_severity
      - medium_complexity
      - medium_disruption
      - no_reboot_needed
      - restrict_strategy

    - name: Read signatures in GPG key
      command: gpg --show-keys --with-fingerprint --with-colons "/etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release"
      changed_when: false
      register: gpg_fingerprints
      check_mode: false
      tags:
      - CJIS-5.10.4.1
      - DISA-STIG-RHEL-08-010019
      - NIST-800-171-3.4.8
      - NIST-800-53-CM-5(3)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-12
      - NIST-800-53-SC-12(3)
      - NIST-800-53-SI-7
      - PCI-DSS-Req-6.2
      - PCI-DSSv4-6.3.3
      - ensure_redhat_gpgkey_installed
      - high_severity
      - medium_complexity
      - medium_disruption
      - no_reboot_needed
      - restrict_strategy

    - name: Set Fact - Installed GPG Fingerprints
      set_fact:
        gpg_installed_fingerprints: |-
          {{ gpg_fingerprints.stdout | regex_findall('^pub.*
          (?:^fpr[:]*)([0-9A-Fa-f]*)', '\1') | list }}
      tags:
      - CJIS-5.10.4.1
      - DISA-STIG-RHEL-08-010019
      - NIST-800-171-3.4.8
      - NIST-800-53-CM-5(3)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-12
      - NIST-800-53-SC-12(3)
      - NIST-800-53-SI-7
      - PCI-DSS-Req-6.2
      - PCI-DSSv4-6.3.3
      - ensure_redhat_gpgkey_installed
      - high_severity
      - medium_complexity
      - medium_disruption
      - no_reboot_needed
      - restrict_strategy

    - name: Set Fact - Valid fingerprints
      set_fact:
        gpg_valid_fingerprints: ("567E347AD0044ADE55BA8A5F199E2F91FD431D51" "6A6AA7C97C8890AEC6AEBFE2F76F66C3D4082792")
      tags:
      - CJIS-5.10.4.1
      - DISA-STIG-RHEL-08-010019
      - NIST-800-171-3.4.8
      - NIST-800-53-CM-5(3)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-12
      - NIST-800-53-SC-12(3)
      - NIST-800-53-SI-7
      - PCI-DSS-Req-6.2
      - PCI-DSSv4-6.3.3
      - ensure_redhat_gpgkey_installed
      - high_severity
      - medium_complexity
      - medium_disruption
      - no_reboot_needed
      - restrict_strategy

    - name: Import RedHat GPG key
      rpm_key:
        state: present
        key: /etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release
      when:
      - gpg_key_directory_permission.stat.mode <= '0755'
      - (gpg_installed_fingerprints | difference(gpg_valid_fingerprints)) | length ==
        0
      - gpg_installed_fingerprints | length > 0
      - ansible_distribution == "RedHat"
      tags:
      - CJIS-5.10.4.1
      - DISA-STIG-RHEL-08-010019
      - NIST-800-171-3.4.8
      - NIST-800-53-CM-5(3)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-12
      - NIST-800-53-SC-12(3)
      - NIST-800-53-SI-7
      - PCI-DSS-Req-6.2
      - PCI-DSSv4-6.3.3
      - ensure_redhat_gpgkey_installed
      - high_severity
      - medium_complexity
      - medium_disruption
      - no_reboot_needed
      - restrict_strategy

#### Rule Ensure Software Patches Installed [ref]

If the system is joined to the Red Hat Network, a Red Hat Satellite Server, or a yum server, run the following command to install updates:

    $ sudo yum update

If the system is not configured to use one of these sources, updates (in the form of RPM packages) can be manually downloaded from the Red Hat Network and installed using `rpm`.
NOTE: U.S. Defense systems are required to be patched within 30 days or sooner as local policy dictates.
Warning: The OVAL feed of Red Hat Enterprise Linux 8 is not a XML file, which may not be understood by all scanners.

Rationale: | Installing software updates is a fundamental mitigation against the exploitation of publicly-known vulnerabilities. If the most recent security patches and updates are not installed, unauthorized users may take advantage of weaknesses in the unpatched software. The lack of prompt attention to patching could result in a system compromise.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_security_patches_up_to_date
Identifiers and References | References: BP28(R08), 18, 20, 4, 5.10.4.1, APO12.01, APO12.02, APO12.03, APO12.04, BAI03.10, DSS05.01, DSS05.02, CCI-000366, CCI-001227, 4.2.3, 4.2.3.12, 4.2.3.7, 4.2.3.9, A.12.6.1, A.14.2.3, A.16.1.3, A.18.2.2, A.18.2.3, SI-2(5), SI-2(c), CM-6(a), ID.RA-1, PR.IP-12, FMT_MOF_EXT.1, Req-6.2, 6.3.3, SRG-OS-000480-GPOS-00227, 1.9, SV-230222r627750_rule

Remediation Shell script ⇲

Complexity: | low
Disruption: | high
Reboot: | true
Strategy: | patch

    yum -y update

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | high
Reboot: | true
Strategy: | patch

    - name: Security patches are up to date
      package:
        name: '*'
        state: latest
      tags:
      - CJIS-5.10.4.1
      - DISA-STIG-RHEL-08-010010
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SI-2(5)
      - NIST-800-53-SI-2(c)
      - PCI-DSS-Req-6.2
      - PCI-DSSv4-6.3.3
      - high_disruption
      - low_complexity
      - medium_severity
      - patch_strategy
      - reboot_required
      - security_patches_up_to_date
      - skip_ansible_lint

Group Account and Access Control Group contains 10 groups and 20 rules

[ref] In traditional Unix security, if an attacker gains shell access to a certain login account, they can perform any action or access any file to which that account has access. Therefore, making it more difficult for unauthorized people to gain shell access to accounts, particularly to privileged accounts, is a necessary part of securing a system. This section introduces mechanisms for restricting access to accounts under Red Hat Enterprise Linux 8.

Group Protect Accounts by Configuring PAM Group contains 4 groups and 12 rules

[ref] PAM, or Pluggable Authentication Modules, is a system which implements modular authentication for Linux programs. PAM provides a flexible and configurable architecture for authentication, and it should be configured to minimize exposure to unnecessary risk. This section contains guidance on how to accomplish that.
PAM is implemented as a set of shared objects which are loaded and invoked whenever an application wishes to authenticate a user. Typically, the application must be running as root in order to take advantage of PAM, because PAM's modules often need to be able to access sensitive stores of account information, such as /etc/shadow. Traditional privileged network listeners (e.g. sshd) or SUID programs (e.g. sudo) already meet this requirement. An SUID root application, userhelper, is provided so that programs which are not SUID or privileged themselves can still take advantage of PAM.
PAM looks in the directory `/etc/pam.d` for application-specific configuration information. For instance, if the program login attempts to authenticate a user, then PAM's libraries follow the instructions in the file `/etc/pam.d/login` to determine what actions should be taken.
One very important file in `/etc/pam.d` is `/etc/pam.d/system-auth`. This file, which is included by many other PAM configuration files, defines 'default' system authentication measures. Modifying this file is a good way to make far-reaching authentication changes, for instance when implementing a centralized authentication service.
Warning: Be careful when making changes to PAM's configuration files. The syntax for these files is complex, and modifications can have unexpected consequences. The default configurations shipped with applications should be sufficient for most users.
Warning: Running `authconfig` or `system-config-authentication` will re-write the PAM configuration files, destroying any manually made changes and replacing them with a series of system defaults. One reference to the configuration file syntax can be found at https://fossies.org/linux/Linux-PAM-docs/doc/sag/Linux-PAM_SAG.pdf.

Group Set Lockouts for Failed Password Attempts Group contains 2 rules

[ref] The `pam_faillock` PAM module provides the capability to lock out user accounts after a number of failed login attempts. Its documentation is available in `/usr/share/doc/pam-VERSION/txts/README.pam_faillock`.
Warning: Locking out user accounts presents the risk of a denial-of-service attack. The lockout policy must weigh whether the risk of such a denial-of-service attack outweighs the benefits of thwarting password guessing attacks.

#### Rule Limit Password Reuse [ref]

Do not allow users to reuse recent passwords. This can be accomplished by using the `remember` option for the `pam_unix` or `pam_pwhistory` PAM modules.
Warning: If the system relies on `authselect` tool to manage PAM settings, the remediation will also use `authselect` tool. However, if any manual modification was made in PAM files, the `authselect` integrity check will fail and the remediation will be aborted in order to preserve intentional changes. In this case, an informative message will be shown in the remediation report.
Warning: Newer versions of `authselect` contain an authselect feature to easily and properly enable `pam_pwhistory.so` module. If this feature is not yet available in your system, an authselect custom profile must be used to avoid integrity issues in PAM files.

Rationale: | Preventing re-use of previous passwords helps ensure that a compromised password is not re-used by a user.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_pam_unix_remember

Identifiers and References

References: BP28(R18), 1, 12, 15, 16, 5, 5.6.2.1.1, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.5.8, CCI-000200, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(f), IA-5(1)(e), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.2.5, 8.3.7, SRG-OS-000077-GPOS-00045, 5.4.3

Remediation Shell script ⇲

    # Remediation is applicable only in certain platforms
    if rpm --quiet -q pam; then

    var_password_pam_unix_remember='5'

    if [ -f /usr/bin/authselect ]; then
        if authselect list-features minimal | grep -q with-pwhistory; then
            if ! authselect check; then
            echo "
            authselect integrity check failed. Remediation aborted!
            This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
            It is not recommended to manually edit the PAM files when authselect tool is available.
            In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
            exit 1
            fi
            authselect enable-feature with-pwhistory

            authselect apply-changes -b
        else

            if ! authselect check; then
            echo "
            authselect integrity check failed. Remediation aborted!
            This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
            It is not recommended to manually edit the PAM files when authselect tool is available.
            In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
            exit 1
            fi

            CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
            # If not already in use, a custom profile is created preserving the enabled features.
            if [[ ! $CURRENT_PROFILE == custom/* ]]; then
                ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
                authselect create-profile hardening -b $CURRENT_PROFILE
                CURRENT_PROFILE="custom/hardening"

                authselect apply-changes -b --backup=before-hardening-custom-profile
                authselect select $CURRENT_PROFILE
                for feature in $ENABLED_FEATURES; do
                    authselect enable-feature $feature;
                done

                authselect apply-changes -b --backup=after-hardening-custom-profile
            fi
            PAM_FILE_NAME=$(basename "/etc/pam.d/system-auth")
            PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

            authselect apply-changes -b
            if ! grep -qP '^\s*password\s+'"requisite"'\s+pam_pwhistory.so\s*.*' "$PAM_FILE_PATH"; then
                # Line matching group + control + module was not found. Check group + module.
                if [ "$(grep -cP '^\s*password\s+.*\s+pam_pwhistory.so\s*' "$PAM_FILE_PATH")" -eq 1 ]; then
                    # The control is updated only if one single line matches.
                    sed -i -E --follow-symlinks 's/^(\s*password\s+).*(\bpam_pwhistory.so.*)/\1'"requisite"' \2/' "$PAM_FILE_PATH"
                else
                    LAST_MATCH_LINE=$(grep -nP "^password.*requisite.*pam_pwquality\.so" "$PAM_FILE_PATH" | tail -n 1 | cut -d: -f 1)
                    if [ ! -z $LAST_MATCH_LINE ]; then
                        sed -i --follow-symlinks $LAST_MATCH_LINE' a password     '"requisite"'    pam_pwhistory.so' "$PAM_FILE_PATH"
                    else
                        echo 'password    '"requisite"'    pam_pwhistory.so' >> "$PAM_FILE_PATH"
                    fi
                fi
            fi
        fi
    else
        if ! grep -qP '^\s*password\s+'"requisite"'\s+pam_pwhistory.so\s*.*' "/etc/pam.d/system-auth"; then
            # Line matching group + control + module was not found. Check group + module.
            if [ "$(grep -cP '^\s*password\s+.*\s+pam_pwhistory.so\s*' "/etc/pam.d/system-auth")" -eq 1 ]; then
                # The control is updated only if one single line matches.
                sed -i -E --follow-symlinks 's/^(\s*password\s+).*(\bpam_pwhistory.so.*)/\1'"requisite"' \2/' "/etc/pam.d/system-auth"
            else
                LAST_MATCH_LINE=$(grep -nP "^password.*requisite.*pam_pwquality\.so" "/etc/pam.d/system-auth" | tail -n 1 | cut -d: -f 1)
                if [ ! -z $LAST_MATCH_LINE ]; then
                    sed -i --follow-symlinks $LAST_MATCH_LINE' a password     '"requisite"'    pam_pwhistory.so' "/etc/pam.d/system-auth"
                else
                    echo 'password    '"requisite"'    pam_pwhistory.so' >> "/etc/pam.d/system-auth"
                fi
            fi
        fi
    fi

    PWHISTORY_CONF="/etc/security/pwhistory.conf"
    if [ -f $PWHISTORY_CONF ]; then
        regex="^\s*remember\s*="
        line="remember = $var_password_pam_unix_remember"
        if ! grep -q $regex $PWHISTORY_CONF; then
            echo $line >> $PWHISTORY_CONF
        else
            sed -i --follow-symlinks 's|^\s*\(remember\s*=\s*\)\(\S\+\)|\1'"$var_password_pam_unix_remember"'|g' $PWHISTORY_CONF
        fi
        if [ -e "/etc/pam.d/system-auth" ] ; then
            PAM_FILE_PATH="/etc/pam.d/system-auth"
            if [ -f /usr/bin/authselect ]; then

                if ! authselect check; then
                echo "
                authselect integrity check failed. Remediation aborted!
                This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
                It is not recommended to manually edit the PAM files when authselect tool is available.
                In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
                exit 1
                fi

                CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
                # If not already in use, a custom profile is created preserving the enabled features.
                if [[ ! $CURRENT_PROFILE == custom/* ]]; then
                    ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
                    authselect create-profile hardening -b $CURRENT_PROFILE
                    CURRENT_PROFILE="custom/hardening"

                    authselect apply-changes -b --backup=before-hardening-custom-profile
                    authselect select $CURRENT_PROFILE
                    for feature in $ENABLED_FEATURES; do
                        authselect enable-feature $feature;
                    done

                    authselect apply-changes -b --backup=after-hardening-custom-profile
                fi
                PAM_FILE_NAME=$(basename "/etc/pam.d/system-auth")
                PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

                authselect apply-changes -b
            fi

        if grep -qP '^\s*password\s.*\bpam_pwhistory.so\s.*\bremember\b' "$PAM_FILE_PATH"; then
            sed -i -E --follow-symlinks 's/(.*password.*pam_pwhistory.so.*)\bremember\b=?[[:alnum:]]*(.*)/\1\2/g' "$PAM_FILE_PATH"
        fi
            if [ -f /usr/bin/authselect ]; then

                authselect apply-changes -b
            fi
        else
            echo "/etc/pam.d/system-auth was not found" >&2
        fi
    else
        PAM_FILE_PATH="/etc/pam.d/system-auth"
        if [ -f /usr/bin/authselect ]; then

            if ! authselect check; then
            echo "
            authselect integrity check failed. Remediation aborted!
            This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
            It is not recommended to manually edit the PAM files when authselect tool is available.
            In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
            exit 1
            fi

            CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
            # If not already in use, a custom profile is created preserving the enabled features.
            if [[ ! $CURRENT_PROFILE == custom/* ]]; then
                ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
                authselect create-profile hardening -b $CURRENT_PROFILE
                CURRENT_PROFILE="custom/hardening"

                authselect apply-changes -b --backup=before-hardening-custom-profile
                authselect select $CURRENT_PROFILE
                for feature in $ENABLED_FEATURES; do
                    authselect enable-feature $feature;
                done

                authselect apply-changes -b --backup=after-hardening-custom-profile
            fi
            PAM_FILE_NAME=$(basename "/etc/pam.d/system-auth")
            PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

            authselect apply-changes -b
        fi
        if ! grep -qP '^\s*password\s+'"requisite"'\s+pam_pwhistory.so\s*.*' "$PAM_FILE_PATH"; then
            # Line matching group + control + module was not found. Check group + module.
            if [ "$(grep -cP '^\s*password\s+.*\s+pam_pwhistory.so\s*' "$PAM_FILE_PATH")" -eq 1 ]; then
                # The control is updated only if one single line matches.
                sed -i -E --follow-symlinks 's/^(\s*password\s+).*(\bpam_pwhistory.so.*)/\1'"requisite"' \2/' "$PAM_FILE_PATH"
            else
                echo 'password    '"requisite"'    pam_pwhistory.so' >> "$PAM_FILE_PATH"
            fi
        fi
        # Check the option
        if ! grep -qP '^\s*password\s+'"requisite"'\s+pam_pwhistory.so\s*.*\sremember\b' "$PAM_FILE_PATH"; then
            sed -i -E --follow-symlinks '/\s*password\s+'"requisite"'\s+pam_pwhistory.so.*/ s/$/ remember='"$var_password_pam_unix_remember"'/' "$PAM_FILE_PATH"
        else
            sed -i -E --follow-symlinks 's/(\s*password\s+'"requisite"'\s+pam_pwhistory.so\s+.*)('"remember"'=)[[:alnum:]]+\s*(.*)/\1\2'"$var_password_pam_unix_remember"' \3/' "$PAM_FILE_PATH"
        fi
        if [ -f /usr/bin/authselect ]; then

            authselect apply-changes -b
        fi
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | configure

    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_unix_remember
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
    - name: XCCDF Value var_password_pam_unix_remember # promote to variable
      set_fact:
        var_password_pam_unix_remember: !!str 5
      tags:
        - always

    - name: Limit Password Reuse - Check if system relies on authselect tool
      ansible.builtin.stat:
        path: /usr/bin/authselect
      register: result_authselect_present
      when: '"pam" in ansible_facts.packages'
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_unix_remember
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: Limit Password Reuse - Collect the available authselect features
      ansible.builtin.command:
        cmd: authselect list-features minimal
      register: result_authselect_available_features
      changed_when: false
      when:
      - '"pam" in ansible_facts.packages'
      - result_authselect_present.stat.exists
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_unix_remember
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: Limit Password Reuse - Enable pam_pwhistory.so using authselect feature
      block:

      - name: Limit Password Reuse - Check integrity of authselect current profile
        ansible.builtin.command:
          cmd: authselect check
        register: result_authselect_check_cmd
        changed_when: false
        failed_when: false

      - name: Limit Password Reuse - Informative message based on the authselect integrity
          check result
        ansible.builtin.assert:
          that:
          - result_authselect_check_cmd.rc == 0
          fail_msg:
          - authselect integrity check failed. Remediation aborted!
          - This remediation could not be applied because an authselect profile was not
            selected or the selected profile is not intact.
          - It is not recommended to manually edit the PAM files when authselect tool
            is available.
          - In cases where the default authselect profile does not cover a specific demand,
            a custom authselect profile is recommended.
          success_msg:
          - authselect integrity check passed

      - name: Limit Password Reuse - Get authselect current features
        ansible.builtin.shell:
          cmd: authselect current | tail -n+3 | awk '{ print $2 }'
        register: result_authselect_features
        changed_when: false
        when:
        - result_authselect_check_cmd is success

      - name: Limit Password Reuse - Ensure "with-pwhistory" feature is enabled using
          authselect tool
        ansible.builtin.command:
          cmd: authselect enable-feature with-pwhistory
        register: result_authselect_enable_feature_cmd
        when:
        - result_authselect_check_cmd is success
        - result_authselect_features.stdout is not search("with-pwhistory")

      - name: Limit Password Reuse - Ensure authselect changes are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b
        when:
        - result_authselect_enable_feature_cmd is not skipped
        - result_authselect_enable_feature_cmd is success
      when:
      - '"pam" in ansible_facts.packages'
      - result_authselect_present.stat.exists
      - result_authselect_available_features.stdout is search("with-pwhistory")
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_unix_remember
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: Limit Password Reuse - Enable pam_pwhistory.so in appropriate PAM files
      block:

      - name: Limit Password Reuse - Define the PAM file to be edited as a local fact
        ansible.builtin.set_fact:
          pam_file_path: /etc/pam.d/system-auth

      - name: Limit Password Reuse - Check if system relies on authselect tool
        ansible.builtin.stat:
          path: /usr/bin/authselect
        register: result_authselect_present

      - name: Limit Password Reuse - Ensure authselect custom profile is used if authselect
          is present
        block:

        - name: Limit Password Reuse - Check integrity of authselect current profile
          ansible.builtin.command:
            cmd: authselect check
          register: result_authselect_check_cmd
          changed_when: false
          failed_when: false

        - name: Limit Password Reuse - Informative message based on the authselect integrity
            check result
          ansible.builtin.assert:
            that:
            - result_authselect_check_cmd.rc == 0
            fail_msg:
            - authselect integrity check failed. Remediation aborted!
            - This remediation could not be applied because an authselect profile was
              not selected or the selected profile is not intact.
            - It is not recommended to manually edit the PAM files when authselect tool
              is available.
            - In cases where the default authselect profile does not cover a specific
              demand, a custom authselect profile is recommended.
            success_msg:
            - authselect integrity check passed

        - name: Limit Password Reuse - Get authselect current profile
          ansible.builtin.shell:
            cmd: authselect current -r | awk '{ print $1 }'
          register: result_authselect_profile
          changed_when: false
          when:
          - result_authselect_check_cmd is success

        - name: Limit Password Reuse - Define the current authselect profile as a local
            fact
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is match("custom/")

        - name: Limit Password Reuse - Define the new authselect custom profile as a local
            fact
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: custom/hardening
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is not match("custom/")

        - name: Limit Password Reuse - Get authselect current features to also enable
            them in the custom profile
          ansible.builtin.shell:
            cmd: authselect current | tail -n+3 | awk '{ print $2 }'
          register: result_authselect_features
          changed_when: false
          when:
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")

        - name: Limit Password Reuse - Check if any custom profile with the same name
            was already created
          ansible.builtin.stat:
            path: /etc/authselect/{{ authselect_custom_profile }}
          register: result_authselect_custom_profile_present
          changed_when: false
          when:
          - authselect_current_profile is not match("custom/")

        - name: Limit Password Reuse - Create an authselect custom profile based on the
            current profile
          ansible.builtin.command:
            cmd: authselect create-profile hardening -b {{ authselect_current_profile
              }}
          when:
          - result_authselect_check_cmd is success
          - authselect_current_profile is not match("custom/")
          - not result_authselect_custom_profile_present.stat.exists

        - name: Limit Password Reuse - Ensure authselect changes are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: Limit Password Reuse - Ensure the authselect custom profile is selected
          ansible.builtin.command:
            cmd: authselect select {{ authselect_custom_profile }}
          register: result_pam_authselect_select_profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: Limit Password Reuse - Restore the authselect features in the custom profile
          ansible.builtin.command:
            cmd: authselect enable-feature {{ item }}
          loop: '{{ result_authselect_features.stdout_lines }}'
          register: result_pam_authselect_restore_features
          when:
          - result_authselect_profile is not skipped
          - result_authselect_features is not skipped
          - result_pam_authselect_select_profile is not skipped

        - name: Limit Password Reuse - Ensure authselect changes are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - result_pam_authselect_restore_features is not skipped

        - name: Limit Password Reuse - Change the PAM file to be edited according to the
            custom authselect profile
          ansible.builtin.set_fact:
            pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
              | basename }}
        when:
        - result_authselect_present.stat.exists

      - name: Limit Password Reuse - Check if expected PAM module line is present in {{
          pam_file_path }}
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          regexp: ^\s*password\s+{{ 'requisite' | regex_escape() }}\s+pam_pwhistory.so\s*.*
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_line_present

      - name: Limit Password Reuse - Include or update the PAM module line in {{ pam_file_path
          }}
        block:

        - name: Limit Password Reuse - Check if required PAM module line is present in
            {{ pam_file_path }} with different control
          ansible.builtin.lineinfile:
            path: '{{ pam_file_path }}'
            regexp: ^\s*password\s+.*\s+pam_pwhistory.so\s*
            state: absent
          check_mode: true
          changed_when: false
          register: result_pam_line_other_control_present

        - name: Limit Password Reuse - Ensure the correct control for the required PAM
            module line in {{ pam_file_path }}
          ansible.builtin.replace:
            dest: '{{ pam_file_path }}'
            regexp: ^(\s*password\s+).*(\bpam_pwhistory.so.*)
            replace: \1requisite \2
          register: result_pam_module_edit
          when:
          - result_pam_line_other_control_present.found == 1

        - name: Limit Password Reuse - Ensure the required PAM module line is included
            in {{ pam_file_path }}
          ansible.builtin.lineinfile:
            dest: '{{ pam_file_path }}'
            insertafter: ^password.*requisite.*pam_pwquality\.so
            line: password    requisite    pam_pwhistory.so
          register: result_pam_module_add
          when:
          - result_pam_line_other_control_present.found == 0 or result_pam_line_other_control_present.found
            > 1

        - name: Limit Password Reuse - Ensure authselect changes are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b
          when:
          - result_authselect_present is defined
          - result_authselect_present.stat.exists
          - |-
            (result_pam_module_add is defined and result_pam_module_add.changed)
             or (result_pam_module_edit is defined and result_pam_module_edit.changed)
        when:
        - result_pam_line_present.found is defined
        - result_pam_line_present.found == 0
      when:
      - '"pam" in ansible_facts.packages'
      - |
        (result_authselect_available_features.stdout is defined and result_authselect_available_features.stdout is not search("with-pwhistory")) or result_authselect_available_features is not defined
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_unix_remember
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: Limit Password Reuse - Check the presence of /etc/security/pwhistory.conf
        file
      ansible.builtin.stat:
        path: /etc/security/pwhistory.conf
      register: result_pwhistory_conf_check
      when: '"pam" in ansible_facts.packages'
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_unix_remember
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: Limit Password Reuse - pam_pwhistory.so parameters are configured in /etc/security/pwhistory.conf
        file
      block:

      - name: Limit Password Reuse - Ensure the pam_pwhistory.so remember parameter in
          /etc/security/pwhistory.conf
        ansible.builtin.lineinfile:
          path: /etc/security/pwhistory.conf
          regexp: ^\s*remember\s*=
          line: remember = {{ var_password_pam_unix_remember }}
          state: present

      - name: Limit Password Reuse - Ensure the pam_pwhistory.so remember parameter is
          removed from PAM files
        block:

        - name: Limit Password Reuse - Check if /etc/pam.d/system-auth file is present
          ansible.builtin.stat:
            path: /etc/pam.d/system-auth
          register: result_pam_file_present

        - name: Limit Password Reuse - Check the proper remediation for the system
          block:

          - name: Limit Password Reuse - Define the PAM file to be edited as a local fact
            ansible.builtin.set_fact:
              pam_file_path: /etc/pam.d/system-auth

          - name: Limit Password Reuse - Check if system relies on authselect tool
            ansible.builtin.stat:
              path: /usr/bin/authselect
            register: result_authselect_present

          - name: Limit Password Reuse - Ensure authselect custom profile is used if authselect
              is present
            block:

            - name: Limit Password Reuse - Check integrity of authselect current profile
              ansible.builtin.command:
                cmd: authselect check
              register: result_authselect_check_cmd
              changed_when: false
              failed_when: false

            - name: Limit Password Reuse - Informative message based on the authselect
                integrity check result
              ansible.builtin.assert:
                that:
                - result_authselect_check_cmd.rc == 0
                fail_msg:
                - authselect integrity check failed. Remediation aborted!
                - This remediation could not be applied because an authselect profile
                  was not selected or the selected profile is not intact.
                - It is not recommended to manually edit the PAM files when authselect
                  tool is available.
                - In cases where the default authselect profile does not cover a specific
                  demand, a custom authselect profile is recommended.
                success_msg:
                - authselect integrity check passed

            - name: Limit Password Reuse - Get authselect current profile
              ansible.builtin.shell:
                cmd: authselect current -r | awk '{ print $1 }'
              register: result_authselect_profile
              changed_when: false
              when:
              - result_authselect_check_cmd is success

            - name: Limit Password Reuse - Define the current authselect profile as a
                local fact
              ansible.builtin.set_fact:
                authselect_current_profile: '{{ result_authselect_profile.stdout }}'
                authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
              when:
              - result_authselect_profile is not skipped
              - result_authselect_profile.stdout is match("custom/")

            - name: Limit Password Reuse - Define the new authselect custom profile as
                a local fact
              ansible.builtin.set_fact:
                authselect_current_profile: '{{ result_authselect_profile.stdout }}'
                authselect_custom_profile: custom/hardening
              when:
              - result_authselect_profile is not skipped
              - result_authselect_profile.stdout is not match("custom/")

            - name: Limit Password Reuse - Get authselect current features to also enable
                them in the custom profile
              ansible.builtin.shell:
                cmd: authselect current | tail -n+3 | awk '{ print $2 }'
              register: result_authselect_features
              changed_when: false
              when:
              - result_authselect_profile is not skipped
              - authselect_current_profile is not match("custom/")

            - name: Limit Password Reuse - Check if any custom profile with the same name
                was already created
              ansible.builtin.stat:
                path: /etc/authselect/{{ authselect_custom_profile }}
              register: result_authselect_custom_profile_present
              changed_when: false
              when:
              - authselect_current_profile is not match("custom/")

            - name: Limit Password Reuse - Create an authselect custom profile based on
                the current profile
              ansible.builtin.command:
                cmd: authselect create-profile hardening -b {{ authselect_current_profile
                  }}
              when:
              - result_authselect_check_cmd is success
              - authselect_current_profile is not match("custom/")
              - not result_authselect_custom_profile_present.stat.exists

            - name: Limit Password Reuse - Ensure authselect changes are applied
              ansible.builtin.command:
                cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
              when:
              - result_authselect_check_cmd is success
              - result_authselect_profile is not skipped
              - authselect_current_profile is not match("custom/")
              - authselect_custom_profile is not match(authselect_current_profile)

            - name: Limit Password Reuse - Ensure the authselect custom profile is selected
              ansible.builtin.command:
                cmd: authselect select {{ authselect_custom_profile }}
              register: result_pam_authselect_select_profile
              when:
              - result_authselect_check_cmd is success
              - result_authselect_profile is not skipped
              - authselect_current_profile is not match("custom/")
              - authselect_custom_profile is not match(authselect_current_profile)

            - name: Limit Password Reuse - Restore the authselect features in the custom
                profile
              ansible.builtin.command:
                cmd: authselect enable-feature {{ item }}
              loop: '{{ result_authselect_features.stdout_lines }}'
              register: result_pam_authselect_restore_features
              when:
              - result_authselect_profile is not skipped
              - result_authselect_features is not skipped
              - result_pam_authselect_select_profile is not skipped

            - name: Limit Password Reuse - Ensure authselect changes are applied
              ansible.builtin.command:
                cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
              when:
              - result_authselect_check_cmd is success
              - result_authselect_profile is not skipped
              - result_pam_authselect_restore_features is not skipped

            - name: Limit Password Reuse - Change the PAM file to be edited according
                to the custom authselect profile
              ansible.builtin.set_fact:
                pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
                  | basename }}
            when:
            - result_authselect_present.stat.exists

          - name: Limit Password Reuse - Ensure the "remember" option from "pam_pwhistory.so"
              is not present in {{ pam_file_path }}
            ansible.builtin.replace:
              dest: '{{ pam_file_path }}'
              regexp: (.*password.*pam_pwhistory.so.*)\bremember\b=?[0-9a-zA-Z]*(.*)
              replace: \1\2
            register: result_pam_option_removal

          - name: Limit Password Reuse - Ensure authselect changes are applied
            ansible.builtin.command:
              cmd: authselect apply-changes -b
            when:
            - result_authselect_present.stat.exists
            - result_pam_option_removal is changed
          when:
          - result_pam_file_present.stat.exists
      when:
      - '"pam" in ansible_facts.packages'
      - result_pwhistory_conf_check.stat.exists
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_unix_remember
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: Limit Password Reuse - pam_pwhistory.so parameters are configured in PAM files
      block:

      - name: Limit Password Reuse - Define the PAM file to be edited as a local fact
        ansible.builtin.set_fact:
          pam_file_path: /etc/pam.d/system-auth

      - name: Limit Password Reuse - Check if system relies on authselect tool
        ansible.builtin.stat:
          path: /usr/bin/authselect
        register: result_authselect_present

      - name: Limit Password Reuse - Ensure authselect custom profile is used if authselect
          is present
        block:

        - name: Limit Password Reuse - Check integrity of authselect current profile
          ansible.builtin.command:
            cmd: authselect check
          register: result_authselect_check_cmd
          changed_when: false
          failed_when: false

        - name: Limit Password Reuse - Informative message based on the authselect integrity
            check result
          ansible.builtin.assert:
            that:
            - result_authselect_check_cmd.rc == 0
            fail_msg:
            - authselect integrity check failed. Remediation aborted!
            - This remediation could not be applied because an authselect profile was
              not selected or the selected profile is not intact.
            - It is not recommended to manually edit the PAM files when authselect tool
              is available.
            - In cases where the default authselect profile does not cover a specific
              demand, a custom authselect profile is recommended.
            success_msg:
            - authselect integrity check passed

        - name: Limit Password Reuse - Get authselect current profile
          ansible.builtin.shell:
            cmd: authselect current -r | awk '{ print $1 }'
          register: result_authselect_profile
          changed_when: false
          when:
          - result_authselect_check_cmd is success

        - name: Limit Password Reuse - Define the current authselect profile as a local
            fact
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is match("custom/")

        - name: Limit Password Reuse - Define the new authselect custom profile as a local
            fact
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: custom/hardening
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is not match("custom/")

        - name: Limit Password Reuse - Get authselect current features to also enable
            them in the custom profile
          ansible.builtin.shell:
            cmd: authselect current | tail -n+3 | awk '{ print $2 }'
          register: result_authselect_features
          changed_when: false
          when:
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")

        - name: Limit Password Reuse - Check if any custom profile with the same name
            was already created
          ansible.builtin.stat:
            path: /etc/authselect/{{ authselect_custom_profile }}
          register: result_authselect_custom_profile_present
          changed_when: false
          when:
          - authselect_current_profile is not match("custom/")

        - name: Limit Password Reuse - Create an authselect custom profile based on the
            current profile
          ansible.builtin.command:
            cmd: authselect create-profile hardening -b {{ authselect_current_profile
              }}
          when:
          - result_authselect_check_cmd is success
          - authselect_current_profile is not match("custom/")
          - not result_authselect_custom_profile_present.stat.exists

        - name: Limit Password Reuse - Ensure authselect changes are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: Limit Password Reuse - Ensure the authselect custom profile is selected
          ansible.builtin.command:
            cmd: authselect select {{ authselect_custom_profile }}
          register: result_pam_authselect_select_profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: Limit Password Reuse - Restore the authselect features in the custom profile
          ansible.builtin.command:
            cmd: authselect enable-feature {{ item }}
          loop: '{{ result_authselect_features.stdout_lines }}'
          register: result_pam_authselect_restore_features
          when:
          - result_authselect_profile is not skipped
          - result_authselect_features is not skipped
          - result_pam_authselect_select_profile is not skipped

        - name: Limit Password Reuse - Ensure authselect changes are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - result_pam_authselect_restore_features is not skipped

        - name: Limit Password Reuse - Change the PAM file to be edited according to the
            custom authselect profile
          ansible.builtin.set_fact:
            pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
              | basename }}
        when:
        - result_authselect_present.stat.exists

      - name: Limit Password Reuse - Check if expected PAM module line is present in {{
          pam_file_path }}
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          regexp: ^\s*password\s+{{ 'requisite' | regex_escape() }}\s+pam_pwhistory.so\s*.*
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_line_present

      - name: Limit Password Reuse - Include or update the PAM module line in {{ pam_file_path
          }}
        block:

        - name: Limit Password Reuse - Check if required PAM module line is present in
            {{ pam_file_path }} with different control
          ansible.builtin.lineinfile:
            path: '{{ pam_file_path }}'
            regexp: ^\s*password\s+.*\s+pam_pwhistory.so\s*
            state: absent
          check_mode: true
          changed_when: false
          register: result_pam_line_other_control_present

        - name: Limit Password Reuse - Ensure the correct control for the required PAM
            module line in {{ pam_file_path }}
          ansible.builtin.replace:
            dest: '{{ pam_file_path }}'
            regexp: ^(\s*password\s+).*(\bpam_pwhistory.so.*)
            replace: \1requisite \2
          register: result_pam_module_edit
          when:
          - result_pam_line_other_control_present.found == 1

        - name: Limit Password Reuse - Ensure the required PAM module line is included
            in {{ pam_file_path }}
          ansible.builtin.lineinfile:
            dest: '{{ pam_file_path }}'
            line: password    requisite    pam_pwhistory.so
          register: result_pam_module_add
          when:
          - result_pam_line_other_control_present.found == 0 or result_pam_line_other_control_present.found
            > 1

        - name: Limit Password Reuse - Ensure authselect changes are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b
          when:
          - result_authselect_present is defined
          - result_authselect_present.stat.exists
          - |-
            (result_pam_module_add is defined and result_pam_module_add.changed)
             or (result_pam_module_edit is defined and result_pam_module_edit.changed)
        when:
        - result_pam_line_present.found is defined
        - result_pam_line_present.found == 0

      - name: Limit Password Reuse - Check if the required PAM module option is present
          in {{ pam_file_path }}
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          regexp: ^\s*password\s+{{ 'requisite' | regex_escape() }}\s+pam_pwhistory.so\s*.*\sremember\b
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_module_remember_option_present

      - name: Limit Password Reuse - Ensure the "remember" PAM option for "pam_pwhistory.so"
          is included in {{ pam_file_path }}
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          backrefs: true
          regexp: ^(\s*password\s+{{ 'requisite' | regex_escape() }}\s+pam_pwhistory.so.*)
          line: \1 remember={{ var_password_pam_unix_remember }}
          state: present
        register: result_pam_remember_add
        when:
        - result_pam_module_remember_option_present.found == 0

      - name: Limit Password Reuse - Ensure the required value for "remember" PAM option
          from "pam_pwhistory.so" in {{ pam_file_path }}
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          backrefs: true
          regexp: ^(\s*password\s+{{ 'requisite' | regex_escape() }}\s+pam_pwhistory.so\s+.*)(remember)=[0-9a-zA-Z]+\s*(.*)
          line: \1\2={{ var_password_pam_unix_remember }} \3
        register: result_pam_remember_edit
        when:
        - result_pam_module_remember_option_present.found > 0

      - name: Limit Password Reuse - Ensure authselect changes are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b
        when:
        - result_authselect_present.stat.exists
        - (result_pam_remember_add is defined and result_pam_remember_add.changed) or
          (result_pam_remember_edit is defined and result_pam_remember_edit.changed)
      when:
      - '"pam" in ansible_facts.packages'
      - not result_pwhistory_conf_check.stat.exists
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_unix_remember
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

#### Rule Lock Accounts After Failed Password Attempts [ref]

This rule configures the system to lock out accounts after a number of incorrect login attempts using `pam_faillock.so`. pam_faillock.so module requires multiple entries in pam files. These entries must be carefully defined to work as expected. Ensure that the file `/etc/security/faillock.conf` contains the following entry: `deny = <count>` Where count should be less than or equal to 5 and greater than 0. In order to avoid errors when manually editing these files, it is recommended to use the appropriate tools, such as `authselect` or `authconfig`, depending on the OS version.
Warning: If the system relies on `authselect` tool to manage PAM settings, the remediation will also use `authselect` tool. However, if any manual modification was made in PAM files, the `authselect` integrity check will fail and the remediation will be aborted in order to preserve intentional changes. In this case, an informative message will be shown in the remediation report. If the system supports the `/etc/security/faillock.conf` file, the pam_faillock parameters should be defined in `faillock.conf` file.

Rationale: | By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, also known as brute-forcing, is reduced. Limits are imposed by locking the account.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_passwords_pam_faillock_deny

Identifiers and References

References: BP28(R18), 1, 12, 15, 16, 5.5.3, DSS05.04, DSS05.10, DSS06.10, 3.1.8, CCI-000044, CCI-002236, CCI-002237, CCI-002238, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, CM-6(a), AC-7(a), PR.AC-7, FIA_AFL.1, Req-8.1.6, 8.3.4, SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005, 5.4.2, 5.5.2, SV-230333r743966_rule

Remediation Shell script ⇲

    # Remediation is applicable only in certain platforms
    if rpm --quiet -q pam; then

    var_accounts_passwords_pam_faillock_deny='5'

    if [ -f /usr/bin/authselect ]; then
        if ! authselect check; then
    echo "
    authselect integrity check failed. Remediation aborted!
    This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
    It is not recommended to manually edit the PAM files when authselect tool is available.
    In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
    exit 1
    fi
    authselect enable-feature with-faillock

    authselect apply-changes -b
    else

    AUTH_FILES=("/etc/pam.d/system-auth" "/etc/pam.d/password-auth")
    for pam_file in "${AUTH_FILES[@]}"
    do
        if ! grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+(preauth silent|authfail).*$' "$pam_file" ; then
            sed -i --follow-symlinks '/^auth.*sufficient.*pam_unix\.so.*/i auth        required      pam_faillock.so preauth silent' "$pam_file"
            sed -i --follow-symlinks '/^auth.*required.*pam_deny\.so.*/i auth        required      pam_faillock.so authfail' "$pam_file"
            sed -i --follow-symlinks '/^account.*required.*pam_unix\.so.*/i account     required      pam_faillock.so' "$pam_file"
        fi
        sed -Ei 's/(auth.*)(\[default=die\])(.*pam_faillock\.so)/\1required     \3/g' "$pam_file"
    done

    fi

    AUTH_FILES=("/etc/pam.d/system-auth" "/etc/pam.d/password-auth")

    FAILLOCK_CONF="/etc/security/faillock.conf"
    if [ -f $FAILLOCK_CONF ]; then
        regex="^\s*deny\s*="
        line="deny = $var_accounts_passwords_pam_faillock_deny"
        if ! grep -q $regex $FAILLOCK_CONF; then
            echo $line >> $FAILLOCK_CONF
        else
            sed -i --follow-symlinks 's|^\s*\(deny\s*=\s*\)\(\S\+\)|\1'"$var_accounts_passwords_pam_faillock_deny"'|g' $FAILLOCK_CONF
        fi
        for pam_file in "${AUTH_FILES[@]}"
        do
            if [ -e "$pam_file" ] ; then
                PAM_FILE_PATH="$pam_file"
                if [ -f /usr/bin/authselect ]; then

                    if ! authselect check; then
                    echo "
                    authselect integrity check failed. Remediation aborted!
                    This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
                    It is not recommended to manually edit the PAM files when authselect tool is available.
                    In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
                    exit 1
                    fi

                    CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
                    # If not already in use, a custom profile is created preserving the enabled features.
                    if [[ ! $CURRENT_PROFILE == custom/* ]]; then
                        ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
                        authselect create-profile hardening -b $CURRENT_PROFILE
                        CURRENT_PROFILE="custom/hardening"

                        authselect apply-changes -b --backup=before-hardening-custom-profile
                        authselect select $CURRENT_PROFILE
                        for feature in $ENABLED_FEATURES; do
                            authselect enable-feature $feature;
                        done

                        authselect apply-changes -b --backup=after-hardening-custom-profile
                    fi
                    PAM_FILE_NAME=$(basename "$pam_file")
                    PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

                    authselect apply-changes -b
                fi

            if grep -qP '^\s*auth\s.*\bpam_faillock.so\s.*\bdeny\b' "$PAM_FILE_PATH"; then
                sed -i -E --follow-symlinks 's/(.*auth.*pam_faillock.so.*)\bdeny\b=?[[:alnum:]]*(.*)/\1\2/g' "$PAM_FILE_PATH"
            fi
                if [ -f /usr/bin/authselect ]; then

                    authselect apply-changes -b
                fi
            else
                echo "$pam_file was not found" >&2
            fi
        done
    else
        for pam_file in "${AUTH_FILES[@]}"
        do
            if ! grep -qE '^\s*auth.*pam_faillock\.so (preauth|authfail).*deny' "$pam_file"; then
                sed -i --follow-symlinks '/^auth.*required.*pam_faillock\.so.*preauth.*silent.*/ s/$/ deny='"$var_accounts_passwords_pam_faillock_deny"'/' "$pam_file"
                sed -i --follow-symlinks '/^auth.*required.*pam_faillock\.so.*authfail.*/ s/$/ deny='"$var_accounts_passwords_pam_faillock_deny"'/' "$pam_file"
            else
                sed -i --follow-symlinks 's/\(^auth.*required.*pam_faillock\.so.*preauth.*silent.*\)\('"deny"'=\)[0-9]\+\(.*\)/\1\2'"$var_accounts_passwords_pam_faillock_deny"'\3/' "$pam_file"
                sed -i --follow-symlinks 's/\(^auth.*required.*pam_faillock\.so.*authfail.*\)\('"deny"'=\)[0-9]\+\(.*\)/\1\2'"$var_accounts_passwords_pam_faillock_deny"'\3/' "$pam_file"
            fi
        done
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.5.3
      - DISA-STIG-RHEL-08-020011
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.6
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_deny
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Lock Accounts After Failed Password Attempts - Check if system relies on authselect
        tool
      ansible.builtin.stat:
        path: /usr/bin/authselect
      register: result_authselect_present
      when: '"pam" in ansible_facts.packages'
      tags:
      - CJIS-5.5.3
      - DISA-STIG-RHEL-08-020011
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.6
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_deny
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Lock Accounts After Failed Password Attempts - Remediation where authselect
        tool is present
      block:

      - name: Lock Accounts After Failed Password Attempts - Check integrity of authselect
          current profile
        ansible.builtin.command:
          cmd: authselect check
        register: result_authselect_check_cmd
        changed_when: false
        failed_when: false

      - name: Lock Accounts After Failed Password Attempts - Informative message based
          on the authselect integrity check result
        ansible.builtin.assert:
          that:
          - result_authselect_check_cmd.rc == 0
          fail_msg:
          - authselect integrity check failed. Remediation aborted!
          - This remediation could not be applied because an authselect profile was not
            selected or the selected profile is not intact.
          - It is not recommended to manually edit the PAM files when authselect tool
            is available.
          - In cases where the default authselect profile does not cover a specific demand,
            a custom authselect profile is recommended.
          success_msg:
          - authselect integrity check passed

      - name: Lock Accounts After Failed Password Attempts - Get authselect current features
        ansible.builtin.shell:
          cmd: authselect current | tail -n+3 | awk '{ print $2 }'
        register: result_authselect_features
        changed_when: false
        when:
        - result_authselect_check_cmd is success

      - name: Lock Accounts After Failed Password Attempts - Ensure "with-faillock" feature
          is enabled using authselect tool
        ansible.builtin.command:
          cmd: authselect enable-feature with-faillock
        register: result_authselect_enable_feature_cmd
        when:
        - result_authselect_check_cmd is success
        - result_authselect_features.stdout is not search("with-faillock")

      - name: Lock Accounts After Failed Password Attempts - Ensure authselect changes
          are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b
        when:
        - result_authselect_enable_feature_cmd is not skipped
        - result_authselect_enable_feature_cmd is success
      when:
      - '"pam" in ansible_facts.packages'
      - result_authselect_present.stat.exists
      tags:
      - CJIS-5.5.3
      - DISA-STIG-RHEL-08-020011
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.6
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_deny
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Lock Accounts After Failed Password Attempts - Remediation where authselect
        tool is not present
      block:

      - name: Lock Accounts After Failed Password Attempts - Check if pam_faillock.so
          is already enabled
        ansible.builtin.lineinfile:
          path: /etc/pam.d/system-auth
          regexp: .*auth.*pam_faillock\.so (preauth|authfail)
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_faillock_is_enabled

      - name: Lock Accounts After Failed Password Attempts - Enable pam_faillock.so preauth
          editing PAM files
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          line: auth        required      pam_faillock.so preauth
          insertbefore: ^auth.*sufficient.*pam_unix\.so.*
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_is_enabled.found == 0

      - name: Lock Accounts After Failed Password Attempts - Enable pam_faillock.so authfail
          editing PAM files
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          line: auth        required      pam_faillock.so authfail
          insertbefore: ^auth.*required.*pam_deny\.so.*
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_is_enabled.found == 0

      - name: Lock Accounts After Failed Password Attempts - Enable pam_faillock.so account
          section editing PAM files
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          line: account     required      pam_faillock.so
          insertbefore: ^account.*required.*pam_unix\.so.*
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_is_enabled.found == 0
      when:
      - '"pam" in ansible_facts.packages'
      - not result_authselect_present.stat.exists
      tags:
      - CJIS-5.5.3
      - DISA-STIG-RHEL-08-020011
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.6
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_deny
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_accounts_passwords_pam_faillock_deny # promote to variable
      set_fact:
        var_accounts_passwords_pam_faillock_deny: !!str 5
      tags:
        - always

    - name: Lock Accounts After Failed Password Attempts - Check the presence of /etc/security/faillock.conf
        file
      ansible.builtin.stat:
        path: /etc/security/faillock.conf
      register: result_faillock_conf_check
      when: '"pam" in ansible_facts.packages'
      tags:
      - CJIS-5.5.3
      - DISA-STIG-RHEL-08-020011
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.6
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_deny
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Lock Accounts After Failed Password Attempts - Ensure the pam_faillock.so
        deny parameter in /etc/security/faillock.conf
      ansible.builtin.lineinfile:
        path: /etc/security/faillock.conf
        regexp: ^\s*deny\s*=
        line: deny = {{ var_accounts_passwords_pam_faillock_deny }}
        state: present
      when:
      - '"pam" in ansible_facts.packages'
      - result_faillock_conf_check.stat.exists
      tags:
      - CJIS-5.5.3
      - DISA-STIG-RHEL-08-020011
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.6
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_deny
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Lock Accounts After Failed Password Attempts - Ensure the pam_faillock.so
        deny parameter not in PAM files
      block:

      - name: Lock Accounts After Failed Password Attempts - Check if /etc/pam.d/system-auth
          file is present
        ansible.builtin.stat:
          path: /etc/pam.d/system-auth
        register: result_pam_file_present

      - name: Lock Accounts After Failed Password Attempts - Check the proper remediation
          for the system
        block:

        - name: Lock Accounts After Failed Password Attempts - Define the PAM file to
            be edited as a local fact
          ansible.builtin.set_fact:
            pam_file_path: /etc/pam.d/system-auth

        - name: Lock Accounts After Failed Password Attempts - Check if system relies
            on authselect tool
          ansible.builtin.stat:
            path: /usr/bin/authselect
          register: result_authselect_present

        - name: Lock Accounts After Failed Password Attempts - Ensure authselect custom
            profile is used if authselect is present
          block:

          - name: Lock Accounts After Failed Password Attempts - Check integrity of authselect
              current profile
            ansible.builtin.command:
              cmd: authselect check
            register: result_authselect_check_cmd
            changed_when: false
            failed_when: false

          - name: Lock Accounts After Failed Password Attempts - Informative message based
              on the authselect integrity check result
            ansible.builtin.assert:
              that:
              - result_authselect_check_cmd.rc == 0
              fail_msg:
              - authselect integrity check failed. Remediation aborted!
              - This remediation could not be applied because an authselect profile was
                not selected or the selected profile is not intact.
              - It is not recommended to manually edit the PAM files when authselect tool
                is available.
              - In cases where the default authselect profile does not cover a specific
                demand, a custom authselect profile is recommended.
              success_msg:
              - authselect integrity check passed

          - name: Lock Accounts After Failed Password Attempts - Get authselect current
              profile
            ansible.builtin.shell:
              cmd: authselect current -r | awk '{ print $1 }'
            register: result_authselect_profile
            changed_when: false
            when:
            - result_authselect_check_cmd is success

          - name: Lock Accounts After Failed Password Attempts - Define the current authselect
              profile as a local fact
            ansible.builtin.set_fact:
              authselect_current_profile: '{{ result_authselect_profile.stdout }}'
              authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
            when:
            - result_authselect_profile is not skipped
            - result_authselect_profile.stdout is match("custom/")

          - name: Lock Accounts After Failed Password Attempts - Define the new authselect
              custom profile as a local fact
            ansible.builtin.set_fact:
              authselect_current_profile: '{{ result_authselect_profile.stdout }}'
              authselect_custom_profile: custom/hardening
            when:
            - result_authselect_profile is not skipped
            - result_authselect_profile.stdout is not match("custom/")

          - name: Lock Accounts After Failed Password Attempts - Get authselect current
              features to also enable them in the custom profile
            ansible.builtin.shell:
              cmd: authselect current | tail -n+3 | awk '{ print $2 }'
            register: result_authselect_features
            changed_when: false
            when:
            - result_authselect_profile is not skipped
            - authselect_current_profile is not match("custom/")

          - name: Lock Accounts After Failed Password Attempts - Check if any custom profile
              with the same name was already created
            ansible.builtin.stat:
              path: /etc/authselect/{{ authselect_custom_profile }}
            register: result_authselect_custom_profile_present
            changed_when: false
            when:
            - authselect_current_profile is not match("custom/")

          - name: Lock Accounts After Failed Password Attempts - Create an authselect
              custom profile based on the current profile
            ansible.builtin.command:
              cmd: authselect create-profile hardening -b {{ authselect_current_profile
                }}
            when:
            - result_authselect_check_cmd is success
            - authselect_current_profile is not match("custom/")
            - not result_authselect_custom_profile_present.stat.exists

          - name: Lock Accounts After Failed Password Attempts - Ensure authselect changes
              are applied
            ansible.builtin.command:
              cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
            when:
            - result_authselect_check_cmd is success
            - result_authselect_profile is not skipped
            - authselect_current_profile is not match("custom/")
            - authselect_custom_profile is not match(authselect_current_profile)

          - name: Lock Accounts After Failed Password Attempts - Ensure the authselect
              custom profile is selected
            ansible.builtin.command:
              cmd: authselect select {{ authselect_custom_profile }}
            register: result_pam_authselect_select_profile
            when:
            - result_authselect_check_cmd is success
            - result_authselect_profile is not skipped
            - authselect_current_profile is not match("custom/")
            - authselect_custom_profile is not match(authselect_current_profile)

          - name: Lock Accounts After Failed Password Attempts - Restore the authselect
              features in the custom profile
            ansible.builtin.command:
              cmd: authselect enable-feature {{ item }}
            loop: '{{ result_authselect_features.stdout_lines }}'
            register: result_pam_authselect_restore_features
            when:
            - result_authselect_profile is not skipped
            - result_authselect_features is not skipped
            - result_pam_authselect_select_profile is not skipped

          - name: Lock Accounts After Failed Password Attempts - Ensure authselect changes
              are applied
            ansible.builtin.command:
              cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
            when:
            - result_authselect_check_cmd is success
            - result_authselect_profile is not skipped
            - result_pam_authselect_restore_features is not skipped

          - name: Lock Accounts After Failed Password Attempts - Change the PAM file to
              be edited according to the custom authselect profile
            ansible.builtin.set_fact:
              pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
                | basename }}
          when:
          - result_authselect_present.stat.exists

        - name: Lock Accounts After Failed Password Attempts - Ensure the "deny" option
            from "pam_faillock.so" is not present in {{ pam_file_path }}
          ansible.builtin.replace:
            dest: '{{ pam_file_path }}'
            regexp: (.*auth.*pam_faillock.so.*)\bdeny\b=?[0-9a-zA-Z]*(.*)
            replace: \1\2
          register: result_pam_option_removal

        - name: Lock Accounts After Failed Password Attempts - Ensure authselect changes
            are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b
          when:
          - result_authselect_present.stat.exists
          - result_pam_option_removal is changed
        when:
        - result_pam_file_present.stat.exists

      - name: Lock Accounts After Failed Password Attempts - Check if /etc/pam.d/password-auth
          file is present
        ansible.builtin.stat:
          path: /etc/pam.d/password-auth
        register: result_pam_file_present

      - name: Lock Accounts After Failed Password Attempts - Check the proper remediation
          for the system
        block:

        - name: Lock Accounts After Failed Password Attempts - Define the PAM file to
            be edited as a local fact
          ansible.builtin.set_fact:
            pam_file_path: /etc/pam.d/password-auth

        - name: Lock Accounts After Failed Password Attempts - Check if system relies
            on authselect tool
          ansible.builtin.stat:
            path: /usr/bin/authselect
          register: result_authselect_present

        - name: Lock Accounts After Failed Password Attempts - Ensure authselect custom
            profile is used if authselect is present
          block:

          - name: Lock Accounts After Failed Password Attempts - Check integrity of authselect
              current profile
            ansible.builtin.command:
              cmd: authselect check
            register: result_authselect_check_cmd
            changed_when: false
            failed_when: false

          - name: Lock Accounts After Failed Password Attempts - Informative message based
              on the authselect integrity check result
            ansible.builtin.assert:
              that:
              - result_authselect_check_cmd.rc == 0
              fail_msg:
              - authselect integrity check failed. Remediation aborted!
              - This remediation could not be applied because an authselect profile was
                not selected or the selected profile is not intact.
              - It is not recommended to manually edit the PAM files when authselect tool
                is available.
              - In cases where the default authselect profile does not cover a specific
                demand, a custom authselect profile is recommended.
              success_msg:
              - authselect integrity check passed

          - name: Lock Accounts After Failed Password Attempts - Get authselect current
              profile
            ansible.builtin.shell:
              cmd: authselect current -r | awk '{ print $1 }'
            register: result_authselect_profile
            changed_when: false
            when:
            - result_authselect_check_cmd is success

          - name: Lock Accounts After Failed Password Attempts - Define the current authselect
              profile as a local fact
            ansible.builtin.set_fact:
              authselect_current_profile: '{{ result_authselect_profile.stdout }}'
              authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
            when:
            - result_authselect_profile is not skipped
            - result_authselect_profile.stdout is match("custom/")

          - name: Lock Accounts After Failed Password Attempts - Define the new authselect
              custom profile as a local fact
            ansible.builtin.set_fact:
              authselect_current_profile: '{{ result_authselect_profile.stdout }}'
              authselect_custom_profile: custom/hardening
            when:
            - result_authselect_profile is not skipped
            - result_authselect_profile.stdout is not match("custom/")

          - name: Lock Accounts After Failed Password Attempts - Get authselect current
              features to also enable them in the custom profile
            ansible.builtin.shell:
              cmd: authselect current | tail -n+3 | awk '{ print $2 }'
            register: result_authselect_features
            changed_when: false
            when:
            - result_authselect_profile is not skipped
            - authselect_current_profile is not match("custom/")

          - name: Lock Accounts After Failed Password Attempts - Check if any custom profile
              with the same name was already created
            ansible.builtin.stat:
              path: /etc/authselect/{{ authselect_custom_profile }}
            register: result_authselect_custom_profile_present
            changed_when: false
            when:
            - authselect_current_profile is not match("custom/")

          - name: Lock Accounts After Failed Password Attempts - Create an authselect
              custom profile based on the current profile
            ansible.builtin.command:
              cmd: authselect create-profile hardening -b {{ authselect_current_profile
                }}
            when:
            - result_authselect_check_cmd is success
            - authselect_current_profile is not match("custom/")
            - not result_authselect_custom_profile_present.stat.exists

          - name: Lock Accounts After Failed Password Attempts - Ensure authselect changes
              are applied
            ansible.builtin.command:
              cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
            when:
            - result_authselect_check_cmd is success
            - result_authselect_profile is not skipped
            - authselect_current_profile is not match("custom/")
            - authselect_custom_profile is not match(authselect_current_profile)

          - name: Lock Accounts After Failed Password Attempts - Ensure the authselect
              custom profile is selected
            ansible.builtin.command:
              cmd: authselect select {{ authselect_custom_profile }}
            register: result_pam_authselect_select_profile
            when:
            - result_authselect_check_cmd is success
            - result_authselect_profile is not skipped
            - authselect_current_profile is not match("custom/")
            - authselect_custom_profile is not match(authselect_current_profile)

          - name: Lock Accounts After Failed Password Attempts - Restore the authselect
              features in the custom profile
            ansible.builtin.command:
              cmd: authselect enable-feature {{ item }}
            loop: '{{ result_authselect_features.stdout_lines }}'
            register: result_pam_authselect_restore_features
            when:
            - result_authselect_profile is not skipped
            - result_authselect_features is not skipped
            - result_pam_authselect_select_profile is not skipped

          - name: Lock Accounts After Failed Password Attempts - Ensure authselect changes
              are applied
            ansible.builtin.command:
              cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
            when:
            - result_authselect_check_cmd is success
            - result_authselect_profile is not skipped
            - result_pam_authselect_restore_features is not skipped

          - name: Lock Accounts After Failed Password Attempts - Change the PAM file to
              be edited according to the custom authselect profile
            ansible.builtin.set_fact:
              pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
                | basename }}
          when:
          - result_authselect_present.stat.exists

        - name: Lock Accounts After Failed Password Attempts - Ensure the "deny" option
            from "pam_faillock.so" is not present in {{ pam_file_path }}
          ansible.builtin.replace:
            dest: '{{ pam_file_path }}'
            regexp: (.*auth.*pam_faillock.so.*)\bdeny\b=?[0-9a-zA-Z]*(.*)
            replace: \1\2
          register: result_pam_option_removal

        - name: Lock Accounts After Failed Password Attempts - Ensure authselect changes
            are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b
          when:
          - result_authselect_present.stat.exists
          - result_pam_option_removal is changed
        when:
        - result_pam_file_present.stat.exists
      when:
      - '"pam" in ansible_facts.packages'
      - result_faillock_conf_check.stat.exists
      tags:
      - CJIS-5.5.3
      - DISA-STIG-RHEL-08-020011
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.6
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_deny
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Lock Accounts After Failed Password Attempts - Ensure the pam_faillock.so
        deny parameter in PAM files
      block:

      - name: Lock Accounts After Failed Password Attempts - Check if pam_faillock.so
          deny parameter is already enabled in pam files
        ansible.builtin.lineinfile:
          path: /etc/pam.d/system-auth
          regexp: .*auth.*pam_faillock\.so (preauth|authfail).*deny
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_faillock_deny_parameter_is_present

      - name: Lock Accounts After Failed Password Attempts - Ensure the inclusion of pam_faillock.so
          preauth deny parameter in auth section
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          backrefs: true
          regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so preauth.*)
          line: \1required\3 deny={{ var_accounts_passwords_pam_faillock_deny }}
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_deny_parameter_is_present.found == 0

      - name: Lock Accounts After Failed Password Attempts - Ensure the inclusion of pam_faillock.so
          authfail deny parameter in auth section
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          backrefs: true
          regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so authfail.*)
          line: \1required\3 deny={{ var_accounts_passwords_pam_faillock_deny }}
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_deny_parameter_is_present.found == 0

      - name: Lock Accounts After Failed Password Attempts - Ensure the desired value
          for pam_faillock.so preauth deny parameter in auth section
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          backrefs: true
          regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so preauth.*)(deny)=[0-9]+(.*)
          line: \1required\3\4={{ var_accounts_passwords_pam_faillock_deny }}\5
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_deny_parameter_is_present.found > 0

      - name: Lock Accounts After Failed Password Attempts - Ensure the desired value
          for pam_faillock.so authfail deny parameter in auth section
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          backrefs: true
          regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so authfail.*)(deny)=[0-9]+(.*)
          line: \1required\3\4={{ var_accounts_passwords_pam_faillock_deny }}\5
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_deny_parameter_is_present.found > 0
      when:
      - '"pam" in ansible_facts.packages'
      - not result_faillock_conf_check.stat.exists
      tags:
      - CJIS-5.5.3
      - DISA-STIG-RHEL-08-020011
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.6
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_deny
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

Group Set Password Quality Requirements Group contains 1 group and 6 rules

[ref] The default `pam_pwquality` PAM module provides strength checking for passwords. It performs a number of checks, such as making sure passwords are not similar to dictionary words, are of at least a certain length, are not the previous password reversed, and are not simply a change of case from the previous password. It can also require passwords to be in certain character classes. The `pam_pwquality` module is the preferred way of configuring password requirements.
The man pages `pam_pwquality(8)` provide information on the capabilities and configuration of each.

Group Set Password Quality Requirements with pam_pwquality Group contains 6 rules

[ref] The `pam_pwquality` PAM module can be configured to meet requirements for a variety of policies.
For example, to configure `pam_pwquality` to require at least one uppercase character, lowercase character, digit, and other (special) character, make sure that `pam_pwquality` exists in `/etc/pam.d/system-auth`:

    password    requisite     pam_pwquality.so try_first_pass local_users_only retry=3 authtok_type=

If no such line exists, add one as the first line of the password section in `/etc/pam.d/system-auth`. Next, modify the settings in `/etc/security/pwquality.conf` to match the following:

    difok = 4
    minlen = 14
    dcredit = -1
    ucredit = -1
    lcredit = -1
    ocredit = -1
    maxrepeat = 3

The arguments can be modified to ensure compliance with your organization's security policy. Discussion of each parameter follows.

#### Rule Ensure PAM Enforces Password Requirements - Minimum Digit Characters [ref]

The pam_pwquality module's `dcredit` parameter controls requirements for usage of digits in a password. When set to a negative number, any password will be required to contain that many digits. When set to a positive number, pam_pwquality will grant +1 additional length credit for each digit. Modify the `dcredit` setting in `/etc/security/pwquality.conf` to require the use of a digit in passwords.

Rationale:

Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks.
Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. Requiring digits makes password guessing attacks more difficult by ensuring a larger search space.

Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_pam_dcredit

Identifiers and References

References: BP28(R18), 1, 12, 15, 16, 5, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000194, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_SMF_EXT.1, Req-8.2.3, 8.3.6, SRG-OS-000071-GPOS-00039, SV-230359r858775_rule

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    # Remediation is applicable only in certain platforms
    if rpm --quiet -q pam; then

    var_password_pam_dcredit='-1'

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^dcredit")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$var_password_pam_dcredit"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^dcredit\\>" "/etc/security/pwquality.conf"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^dcredit\\>.*/$escaped_formatted_output/gi" "/etc/security/pwquality.conf"
    else
        if [[ -s "/etc/security/pwquality.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/security/pwquality.conf" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/security/pwquality.conf"
        fi
        cce=""
        printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/security/pwquality.conf" >> "/etc/security/pwquality.conf"
        printf '%s\n' "$formatted_output" >> "/etc/security/pwquality.conf"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - DISA-STIG-RHEL-08-020130
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(a)
      - NIST-800-53-IA-5(4)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.3
      - PCI-DSSv4-8.3.6
      - accounts_password_pam_dcredit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_password_pam_dcredit # promote to variable
      set_fact:
        var_password_pam_dcredit: !!str -1
      tags:
        - always

    - name: Ensure PAM Enforces Password Requirements - Minimum Digit Characters - Ensure
        PAM variable dcredit is set accordingly
      ansible.builtin.lineinfile:
        create: true
        dest: /etc/security/pwquality.conf
        regexp: ^#?\s*dcredit
        line: dcredit = {{ var_password_pam_dcredit }}
      when: '"pam" in ansible_facts.packages'
      tags:
      - DISA-STIG-RHEL-08-020130
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(a)
      - NIST-800-53-IA-5(4)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.3
      - PCI-DSSv4-8.3.6
      - accounts_password_pam_dcredit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

#### Rule Ensure PAM Enforces Password Requirements - Minimum Different Characters [ref]

The pam_pwquality module's `difok` parameter sets the number of characters in a password that must not be present in and old password during a password change. Modify the `difok` setting in `/etc/security/pwquality.conf` to equal 3 to require differing characters when changing passwords.

Rationale:

Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute–force attacks.
Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.
Requiring a minimum number of different characters during password changes ensures that newly changed passwords should not resemble previously compromised ones. Note that passwords which are changed on compromised systems will still be compromised, however.

Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_pam_difok

Identifiers and References

References: 1, 12, 15, 16, 5, 5.6.2.1.1, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000195, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(b), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, SRG-OS-000072-GPOS-00040, SV-230363r858783_rule

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    # Remediation is applicable only in certain platforms
    if rpm --quiet -q pam; then

    var_password_pam_difok='3'

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^difok")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$var_password_pam_difok"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^difok\\>" "/etc/security/pwquality.conf"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^difok\\>.*/$escaped_formatted_output/gi" "/etc/security/pwquality.conf"
    else
        if [[ -s "/etc/security/pwquality.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/security/pwquality.conf" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/security/pwquality.conf"
        fi
        cce=""
        printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/security/pwquality.conf" >> "/etc/security/pwquality.conf"
        printf '%s\n' "$formatted_output" >> "/etc/security/pwquality.conf"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.6.2.1.1
      - DISA-STIG-RHEL-08-020170
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(b)
      - NIST-800-53-IA-5(4)
      - NIST-800-53-IA-5(c)
      - accounts_password_pam_difok
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_password_pam_difok # promote to variable
      set_fact:
        var_password_pam_difok: !!str 3
      tags:
        - always

    - name: Ensure PAM Enforces Password Requirements - Minimum Different Characters -
        Ensure PAM variable difok is set accordingly
      ansible.builtin.lineinfile:
        create: true
        dest: /etc/security/pwquality.conf
        regexp: ^#?\s*difok
        line: difok = {{ var_password_pam_difok }}
      when: '"pam" in ansible_facts.packages'
      tags:
      - CJIS-5.6.2.1.1
      - DISA-STIG-RHEL-08-020170
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(b)
      - NIST-800-53-IA-5(4)
      - NIST-800-53-IA-5(c)
      - accounts_password_pam_difok
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

#### Rule Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters [ref]

The pam_pwquality module's `lcredit` parameter controls requirements for usage of lowercase letters in a password. When set to a negative number, any password will be required to contain that many lowercase characters. When set to a positive number, pam_pwquality will grant +1 additional length credit for each lowercase character. Modify the `lcredit` setting in `/etc/security/pwquality.conf` to require the use of a lowercase character in passwords.

Rationale:

Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks.
Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possble combinations that need to be tested before the password is compromised. Requiring a minimum number of lowercase characters makes password guessing attacks more difficult by ensuring a larger search space.

Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_pam_lcredit

Identifiers and References

References: BP28(R18), 1, 12, 15, 16, 5, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000193, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_SMF_EXT.1, Req-8.2.3, 8.3.6, SRG-OS-000070-GPOS-00038, SV-230358r858773_rule

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    # Remediation is applicable only in certain platforms
    if rpm --quiet -q pam; then

    var_password_pam_lcredit='-2'

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^lcredit")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$var_password_pam_lcredit"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^lcredit\\>" "/etc/security/pwquality.conf"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^lcredit\\>.*/$escaped_formatted_output/gi" "/etc/security/pwquality.conf"
    else
        if [[ -s "/etc/security/pwquality.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/security/pwquality.conf" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/security/pwquality.conf"
        fi
        cce=""
        printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/security/pwquality.conf" >> "/etc/security/pwquality.conf"
        printf '%s\n' "$formatted_output" >> "/etc/security/pwquality.conf"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - DISA-STIG-RHEL-08-020120
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(a)
      - NIST-800-53-IA-5(4)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.3
      - PCI-DSSv4-8.3.6
      - accounts_password_pam_lcredit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_password_pam_lcredit # promote to variable
      set_fact:
        var_password_pam_lcredit: !!str -2
      tags:
        - always

    - name: Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters -
        Ensure PAM variable lcredit is set accordingly
      ansible.builtin.lineinfile:
        create: true
        dest: /etc/security/pwquality.conf
        regexp: ^#?\s*lcredit
        line: lcredit = {{ var_password_pam_lcredit }}
      when: '"pam" in ansible_facts.packages'
      tags:
      - DISA-STIG-RHEL-08-020120
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(a)
      - NIST-800-53-IA-5(4)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.3
      - PCI-DSSv4-8.3.6
      - accounts_password_pam_lcredit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

#### Rule Ensure PAM Enforces Password Requirements - Minimum Special Characters [ref]

The pam_pwquality module's `ocredit=` parameter controls requirements for usage of special (or "other") characters in a password. When set to a negative number, any password will be required to contain that many special characters. When set to a positive number, pam_pwquality will grant +1 additional length credit for each special character. Modify the `ocredit` setting in `/etc/security/pwquality.conf` to equal -2 to require use of a special character in passwords.

Rationale:

Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks.
Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. Requiring a minimum number of special characters makes password guessing attacks more difficult by ensuring a larger search space.

Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_pam_ocredit

Identifiers and References

References: BP28(R18), 1, 12, 15, 16, 5, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-001619, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_SMF_EXT.1, SRG-OS-000266-GPOS-00101, SV-230375r858787_rule

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    # Remediation is applicable only in certain platforms
    if rpm --quiet -q pam; then

    var_password_pam_ocredit='-2'

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^ocredit")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$var_password_pam_ocredit"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^ocredit\\>" "/etc/security/pwquality.conf"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^ocredit\\>.*/$escaped_formatted_output/gi" "/etc/security/pwquality.conf"
    else
        if [[ -s "/etc/security/pwquality.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/security/pwquality.conf" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/security/pwquality.conf"
        fi
        cce=""
        printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/security/pwquality.conf" >> "/etc/security/pwquality.conf"
        printf '%s\n' "$formatted_output" >> "/etc/security/pwquality.conf"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - DISA-STIG-RHEL-08-020280
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(a)
      - NIST-800-53-IA-5(4)
      - NIST-800-53-IA-5(c)
      - accounts_password_pam_ocredit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_password_pam_ocredit # promote to variable
      set_fact:
        var_password_pam_ocredit: !!str -2
      tags:
        - always

    - name: Ensure PAM Enforces Password Requirements - Minimum Special Characters - Ensure
        PAM variable ocredit is set accordingly
      ansible.builtin.lineinfile:
        create: true
        dest: /etc/security/pwquality.conf
        regexp: ^#?\s*ocredit
        line: ocredit = {{ var_password_pam_ocredit }}
      when: '"pam" in ansible_facts.packages'
      tags:
      - DISA-STIG-RHEL-08-020280
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(a)
      - NIST-800-53-IA-5(4)
      - NIST-800-53-IA-5(c)
      - accounts_password_pam_ocredit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

#### Rule Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted Per-Session [ref]

To configure the number of retry prompts that are permitted per-session: Edit the `/etc/security/pwquality.conf` to include `retry=3`, or a lower value if site policy is more restrictive. The DoD requirement is a maximum of 3 prompts per session.
Rationale: | Setting the password retry prompts that are permitted on a per-session basis to a low value requires some software, such as SSH, to re-connect. This can slow down and draw additional attention to some types of password-guessing attacks. Note that this is different from account lockout, which is provided by the pam_faillock module.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_pam_retry

Identifiers and References

References: 1, 11, 12, 15, 16, 3, 5, 9, 5.5.3, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000192, CCI-000366, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, CM-6(a), AC-7(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, PR.IP-1, FMT_MOF_EXT.1, SRG-OS-000069-GPOS-00037, SRG-OS-000480-GPOS-00227, 5.5.1, SV-251716r858737_rule

Remediation Shell script ⇲

    # Remediation is applicable only in certain platforms
    if rpm --quiet -q pam; then

    var_password_pam_retry='3'

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^retry")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$var_password_pam_retry"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^retry\\>" "/etc/security/pwquality.conf"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^retry\\>.*/$escaped_formatted_output/gi" "/etc/security/pwquality.conf"
    else
        if [[ -s "/etc/security/pwquality.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/security/pwquality.conf" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/security/pwquality.conf"
        fi
        cce=""
        printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/security/pwquality.conf" >> "/etc/security/pwquality.conf"
        printf '%s\n' "$formatted_output" >> "/etc/security/pwquality.conf"
    fi

    		if [ -e "/etc/pam.d/password-auth" ] ; then
        PAM_FILE_PATH="/etc/pam.d/password-auth"
        if [ -f /usr/bin/authselect ]; then

            if ! authselect check; then
            echo "
            authselect integrity check failed. Remediation aborted!
            This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
            It is not recommended to manually edit the PAM files when authselect tool is available.
            In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
            exit 1
            fi

            CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
            # If not already in use, a custom profile is created preserving the enabled features.
            if [[ ! $CURRENT_PROFILE == custom/* ]]; then
                ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
                authselect create-profile hardening -b $CURRENT_PROFILE
                CURRENT_PROFILE="custom/hardening"

                authselect apply-changes -b --backup=before-hardening-custom-profile
                authselect select $CURRENT_PROFILE
                for feature in $ENABLED_FEATURES; do
                    authselect enable-feature $feature;
                done

                authselect apply-changes -b --backup=after-hardening-custom-profile
            fi
            PAM_FILE_NAME=$(basename "/etc/pam.d/password-auth")
            PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

            authselect apply-changes -b
        fi

    if grep -qP '^\s*password\s+'".*"'\s+pam_pwquality.so\s.*\bretry\b' "$PAM_FILE_PATH"; then
        sed -i -E --follow-symlinks 's/(.*password.*'".*"'.*pam_pwquality.so.*)\sretry=?[[:alnum:]]*(.*)/\1\2/g' "$PAM_FILE_PATH"
    fi
        if [ -f /usr/bin/authselect ]; then

            authselect apply-changes -b
        fi
    else
        echo "/etc/pam.d/password-auth was not found" >&2
    fi

    		if [ -e "/etc/pam.d/system-auth" ] ; then
        PAM_FILE_PATH="/etc/pam.d/system-auth"
        if [ -f /usr/bin/authselect ]; then

            if ! authselect check; then
            echo "
            authselect integrity check failed. Remediation aborted!
            This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
            It is not recommended to manually edit the PAM files when authselect tool is available.
            In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
            exit 1
            fi

            CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
            # If not already in use, a custom profile is created preserving the enabled features.
            if [[ ! $CURRENT_PROFILE == custom/* ]]; then
                ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
                authselect create-profile hardening -b $CURRENT_PROFILE
                CURRENT_PROFILE="custom/hardening"

                authselect apply-changes -b --backup=before-hardening-custom-profile
                authselect select $CURRENT_PROFILE
                for feature in $ENABLED_FEATURES; do
                    authselect enable-feature $feature;
                done

                authselect apply-changes -b --backup=after-hardening-custom-profile
            fi
            PAM_FILE_NAME=$(basename "/etc/pam.d/system-auth")
            PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

            authselect apply-changes -b
        fi

    if grep -qP '^\s*password\s+'".*"'\s+pam_pwquality.so\s.*\bretry\b' "$PAM_FILE_PATH"; then
        sed -i -E --follow-symlinks 's/(.*password.*'".*"'.*pam_pwquality.so.*)\sretry=?[[:alnum:]]*(.*)/\1\2/g' "$PAM_FILE_PATH"
    fi
        if [ -f /usr/bin/authselect ]; then

            authselect apply-changes -b
        fi
    else
        echo "/etc/pam.d/system-auth was not found" >&2
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | configure

    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.5.3
      - DISA-STIG-RHEL-08-020104
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(4)
      - accounts_password_pam_retry
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
    - name: XCCDF Value var_password_pam_retry # promote to variable
      set_fact:
        var_password_pam_retry: !!str 3
      tags:
        - always

    - name: Ensure PAM variable retry is set accordingly
      ansible.builtin.lineinfile:
        create: true
        dest: /etc/security/pwquality.conf
        regexp: ^\s*retry
        line: retry = {{ var_password_pam_retry }}
      when: '"pam" in ansible_facts.packages'
      tags:
      - CJIS-5.5.3
      - DISA-STIG-RHEL-08-020104
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(4)
      - accounts_password_pam_retry
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted
        Per-Session - Check if /etc/pam.d/password-auth file is present
      ansible.builtin.stat:
        path: /etc/pam.d/password-auth
      register: result_pam_file_present
      when: '"pam" in ansible_facts.packages'
      tags:
      - CJIS-5.5.3
      - DISA-STIG-RHEL-08-020104
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(4)
      - accounts_password_pam_retry
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted
        Per-Session - Check the proper remediation for the system
      block:

      - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
          Permitted Per-Session - Define the PAM file to be edited as a local fact
        ansible.builtin.set_fact:
          pam_file_path: /etc/pam.d/password-auth

      - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
          Permitted Per-Session - Check if system relies on authselect tool
        ansible.builtin.stat:
          path: /usr/bin/authselect
        register: result_authselect_present

      - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
          Permitted Per-Session - Ensure authselect custom profile is used if authselect
          is present
        block:

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Check integrity of authselect current profile
          ansible.builtin.command:
            cmd: authselect check
          register: result_authselect_check_cmd
          changed_when: false
          failed_when: false

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Informative message based on the authselect integrity
            check result
          ansible.builtin.assert:
            that:
            - result_authselect_check_cmd.rc == 0
            fail_msg:
            - authselect integrity check failed. Remediation aborted!
            - This remediation could not be applied because an authselect profile was
              not selected or the selected profile is not intact.
            - It is not recommended to manually edit the PAM files when authselect tool
              is available.
            - In cases where the default authselect profile does not cover a specific
              demand, a custom authselect profile is recommended.
            success_msg:
            - authselect integrity check passed

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Get authselect current profile
          ansible.builtin.shell:
            cmd: authselect current -r | awk '{ print $1 }'
          register: result_authselect_profile
          changed_when: false
          when:
          - result_authselect_check_cmd is success

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Define the current authselect profile as a local fact
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is match("custom/")

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Define the new authselect custom profile as a local
            fact
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: custom/hardening
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is not match("custom/")

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Get authselect current features to also enable them
            in the custom profile
          ansible.builtin.shell:
            cmd: authselect current | tail -n+3 | awk '{ print $2 }'
          register: result_authselect_features
          changed_when: false
          when:
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Check if any custom profile with the same name was
            already created
          ansible.builtin.stat:
            path: /etc/authselect/{{ authselect_custom_profile }}
          register: result_authselect_custom_profile_present
          changed_when: false
          when:
          - authselect_current_profile is not match("custom/")

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Create an authselect custom profile based on the current
            profile
          ansible.builtin.command:
            cmd: authselect create-profile hardening -b {{ authselect_current_profile
              }}
          when:
          - result_authselect_check_cmd is success
          - authselect_current_profile is not match("custom/")
          - not result_authselect_custom_profile_present.stat.exists

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Ensure authselect changes are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Ensure the authselect custom profile is selected
          ansible.builtin.command:
            cmd: authselect select {{ authselect_custom_profile }}
          register: result_pam_authselect_select_profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Restore the authselect features in the custom profile
          ansible.builtin.command:
            cmd: authselect enable-feature {{ item }}
          loop: '{{ result_authselect_features.stdout_lines }}'
          register: result_pam_authselect_restore_features
          when:
          - result_authselect_profile is not skipped
          - result_authselect_features is not skipped
          - result_pam_authselect_select_profile is not skipped

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Ensure authselect changes are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - result_pam_authselect_restore_features is not skipped

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Change the PAM file to be edited according to the
            custom authselect profile
          ansible.builtin.set_fact:
            pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
              | basename }}
        when:
        - result_authselect_present.stat.exists

      - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
          Permitted Per-Session - Ensure the "retry" option from "pam_pwquality.so" is
          not present in {{ pam_file_path }}
        ansible.builtin.replace:
          dest: '{{ pam_file_path }}'
          regexp: (.*password.*{{ '.*' | regex_escape() }}.*pam_pwquality.so.*)\bretry\b=?[0-9a-zA-Z]*(.*)
          replace: \1\2
        register: result_pam_option_removal

      - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
          Permitted Per-Session - Ensure authselect changes are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b
        when:
        - result_authselect_present.stat.exists
        - result_pam_option_removal is changed
      when:
      - '"pam" in ansible_facts.packages'
      - result_pam_file_present.stat.exists
      tags:
      - CJIS-5.5.3
      - DISA-STIG-RHEL-08-020104
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(4)
      - accounts_password_pam_retry
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted
        Per-Session - Check if /etc/pam.d/system-auth file is present
      ansible.builtin.stat:
        path: /etc/pam.d/system-auth
      register: result_pam_file_present
      when: '"pam" in ansible_facts.packages'
      tags:
      - CJIS-5.5.3
      - DISA-STIG-RHEL-08-020104
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(4)
      - accounts_password_pam_retry
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted
        Per-Session - Check the proper remediation for the system
      block:

      - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
          Permitted Per-Session - Define the PAM file to be edited as a local fact
        ansible.builtin.set_fact:
          pam_file_path: /etc/pam.d/system-auth

      - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
          Permitted Per-Session - Check if system relies on authselect tool
        ansible.builtin.stat:
          path: /usr/bin/authselect
        register: result_authselect_present

      - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
          Permitted Per-Session - Ensure authselect custom profile is used if authselect
          is present
        block:

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Check integrity of authselect current profile
          ansible.builtin.command:
            cmd: authselect check
          register: result_authselect_check_cmd
          changed_when: false
          failed_when: false

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Informative message based on the authselect integrity
            check result
          ansible.builtin.assert:
            that:
            - result_authselect_check_cmd.rc == 0
            fail_msg:
            - authselect integrity check failed. Remediation aborted!
            - This remediation could not be applied because an authselect profile was
              not selected or the selected profile is not intact.
            - It is not recommended to manually edit the PAM files when authselect tool
              is available.
            - In cases where the default authselect profile does not cover a specific
              demand, a custom authselect profile is recommended.
            success_msg:
            - authselect integrity check passed

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Get authselect current profile
          ansible.builtin.shell:
            cmd: authselect current -r | awk '{ print $1 }'
          register: result_authselect_profile
          changed_when: false
          when:
          - result_authselect_check_cmd is success

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Define the current authselect profile as a local fact
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is match("custom/")

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Define the new authselect custom profile as a local
            fact
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: custom/hardening
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is not match("custom/")

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Get authselect current features to also enable them
            in the custom profile
          ansible.builtin.shell:
            cmd: authselect current | tail -n+3 | awk '{ print $2 }'
          register: result_authselect_features
          changed_when: false
          when:
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Check if any custom profile with the same name was
            already created
          ansible.builtin.stat:
            path: /etc/authselect/{{ authselect_custom_profile }}
          register: result_authselect_custom_profile_present
          changed_when: false
          when:
          - authselect_current_profile is not match("custom/")

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Create an authselect custom profile based on the current
            profile
          ansible.builtin.command:
            cmd: authselect create-profile hardening -b {{ authselect_current_profile
              }}
          when:
          - result_authselect_check_cmd is success
          - authselect_current_profile is not match("custom/")
          - not result_authselect_custom_profile_present.stat.exists

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Ensure authselect changes are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Ensure the authselect custom profile is selected
          ansible.builtin.command:
            cmd: authselect select {{ authselect_custom_profile }}
          register: result_pam_authselect_select_profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Restore the authselect features in the custom profile
          ansible.builtin.command:
            cmd: authselect enable-feature {{ item }}
          loop: '{{ result_authselect_features.stdout_lines }}'
          register: result_pam_authselect_restore_features
          when:
          - result_authselect_profile is not skipped
          - result_authselect_features is not skipped
          - result_pam_authselect_select_profile is not skipped

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Ensure authselect changes are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - result_pam_authselect_restore_features is not skipped

        - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
            Permitted Per-Session - Change the PAM file to be edited according to the
            custom authselect profile
          ansible.builtin.set_fact:
            pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
              | basename }}
        when:
        - result_authselect_present.stat.exists

      - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
          Permitted Per-Session - Ensure the "retry" option from "pam_pwquality.so" is
          not present in {{ pam_file_path }}
        ansible.builtin.replace:
          dest: '{{ pam_file_path }}'
          regexp: (.*password.*{{ '.*' | regex_escape() }}.*pam_pwquality.so.*)\bretry\b=?[0-9a-zA-Z]*(.*)
          replace: \1\2
        register: result_pam_option_removal

      - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
          Permitted Per-Session - Ensure authselect changes are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b
        when:
        - result_authselect_present.stat.exists
        - result_pam_option_removal is changed
      when:
      - '"pam" in ansible_facts.packages'
      - result_pam_file_present.stat.exists
      tags:
      - CJIS-5.5.3
      - DISA-STIG-RHEL-08-020104
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(4)
      - accounts_password_pam_retry
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

#### Rule Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters [ref]

The pam_pwquality module's `ucredit=` parameter controls requirements for usage of uppercase letters in a password. When set to a negative number, any password will be required to contain that many uppercase characters. When set to a positive number, pam_pwquality will grant +1 additional length credit for each uppercase character. Modify the `ucredit` setting in `/etc/security/pwquality.conf` to require the use of an uppercase character in passwords.

Rationale:

Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks.
Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.

Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_pam_ucredit

Identifiers and References

References: BP28(R18), 1, 12, 15, 16, 5, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000192, CCI-000193, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_SMF_EXT.1, Req-8.2.3, SRG-OS-000069-GPOS-00037, SRG-OS-000070-GPOS-00038, SV-230357r858771_rule

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    # Remediation is applicable only in certain platforms
    if rpm --quiet -q pam; then

    var_password_pam_ucredit='-2'

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^ucredit")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$var_password_pam_ucredit"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^ucredit\\>" "/etc/security/pwquality.conf"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^ucredit\\>.*/$escaped_formatted_output/gi" "/etc/security/pwquality.conf"
    else
        if [[ -s "/etc/security/pwquality.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/security/pwquality.conf" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/security/pwquality.conf"
        fi
        cce=""
        printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/security/pwquality.conf" >> "/etc/security/pwquality.conf"
        printf '%s\n' "$formatted_output" >> "/etc/security/pwquality.conf"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - DISA-STIG-RHEL-08-020110
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(a)
      - NIST-800-53-IA-5(4)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.3
      - accounts_password_pam_ucredit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_password_pam_ucredit # promote to variable
      set_fact:
        var_password_pam_ucredit: !!str -2
      tags:
        - always

    - name: Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters -
        Ensure PAM variable ucredit is set accordingly
      ansible.builtin.lineinfile:
        create: true
        dest: /etc/security/pwquality.conf
        regexp: ^#?\s*ucredit
        line: ucredit = {{ var_password_pam_ucredit }}
      when: '"pam" in ansible_facts.packages'
      tags:
      - DISA-STIG-RHEL-08-020110
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(a)
      - NIST-800-53-IA-5(4)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.3
      - accounts_password_pam_ucredit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

Group Set Password Hashing Algorithm Group contains 4 rules
[ref] The system's default algorithm for storing password hashes in `/etc/shadow` is SHA-512. This can be configured in several locations.

#### Rule Set Password Hashing Algorithm in /etc/libuser.conf [ref]

In `/etc/libuser.conf`, add or correct the following line in its `[defaults]` section to ensure the system will use the SHA-512 algorithm for password hashing:

    crypt_style = sha512

Rationale:

Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kepy in plain text.
This setting ensures user and group account administration utilities are configured to store only encrypted representations of passwords. Additionally, the `crypt_style` configuration option ensures the use of a strong hashing algorithm that makes password cracking attacks more difficult.

Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_set_password_hashing_algorithm_libuserconf

Identifiers and References

References: 1, 12, 15, 16, 5, 5.6.2.2, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.13.11, CCI-000196, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0418, 1055, 1402, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(c), CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.2.1, 8.3.2, SRG-OS-000073-GPOS-00041

Remediation Shell script ⇲

    # Remediation is applicable only in certain platforms
    if rpm --quiet -q libuser; then

    LIBUSER_CONF="/etc/libuser.conf"
    CRYPT_STYLE_REGEX='[[:space:]]*\[defaults](.*(\n)+)+?[[:space:]]*crypt_style[[:space:]]*'

    # Try find crypt_style in [defaults] section. If it is here, then change algorithm to sha512.
    # If it isn't here, then add it to [defaults] section.
    if grep -qzosP $CRYPT_STYLE_REGEX $LIBUSER_CONF ; then
            sed -i "s/\(crypt_style[[:space:]]*=[[:space:]]*\).*/\1sha512/g" $LIBUSER_CONF
    elif grep -qs "\[defaults]" $LIBUSER_CONF ; then
            sed -i "/[[:space:]]*\[defaults]/a crypt_style = sha512" $LIBUSER_CONF
    else
            echo -e "[defaults]\ncrypt_style = sha512" >> $LIBUSER_CONF
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.6.2.2
      - NIST-800-171-3.13.11
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.1
      - PCI-DSSv4-8.3.2
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - set_password_hashing_algorithm_libuserconf

    - name: Set Password Hashing Algorithm in /etc/libuser.conf
      lineinfile:
        dest: /etc/libuser.conf
        insertafter: ^\s*\[defaults]
        regexp: ^#?crypt_style
        line: crypt_style = sha512
        state: present
        create: true
      when: '"libuser" in ansible_facts.packages'
      tags:
      - CJIS-5.6.2.2
      - NIST-800-171-3.13.11
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.1
      - PCI-DSSv4-8.3.2
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - set_password_hashing_algorithm_libuserconf

#### Rule Set Password Hashing Algorithm in /etc/login.defs [ref]

In `/etc/login.defs`, add or correct the following line to ensure the system will use SHA512 as the hashing algorithm:

    ENCRYPT_METHOD SHA512

Rationale:

Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kept in plain text.
Using a stronger hashing algorithm makes password cracking attacks more difficult.

Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_set_password_hashing_algorithm_logindefs

Identifiers and References

References: BP28(R32), 1, 12, 15, 16, 5, 5.6.2.2, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.13.11, CCI-000196, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0418, 1055, 1402, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(c), CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.2.1, 8.3.2, SRG-OS-000073-GPOS-00041, 5.5.4, SV-230231r877397_rule

Remediation Shell script ⇲

    # Remediation is applicable only in certain platforms
    if rpm --quiet -q shadow-utils; then

    var_password_hashing_algorithm='SHA512'

    if grep --silent ^ENCRYPT_METHOD /etc/login.defs ; then
    	sed -i "s/^ENCRYPT_METHOD .*/ENCRYPT_METHOD $var_password_hashing_algorithm/g" /etc/login.defs
    else
    	echo "" >> /etc/login.defs
    	echo "ENCRYPT_METHOD $var_password_hashing_algorithm" >> /etc/login.defs
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.6.2.2
      - DISA-STIG-RHEL-08-010110
      - NIST-800-171-3.13.11
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.1
      - PCI-DSSv4-8.3.2
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - set_password_hashing_algorithm_logindefs
    - name: XCCDF Value var_password_hashing_algorithm # promote to variable
      set_fact:
        var_password_hashing_algorithm: !!str SHA512
      tags:
        - always

    - name: Set Password Hashing Algorithm in /etc/login.defs
      lineinfile:
        dest: /etc/login.defs
        regexp: ^#?ENCRYPT_METHOD
        line: ENCRYPT_METHOD {{ var_password_hashing_algorithm }}
        state: present
        create: true
      when: '"shadow-utils" in ansible_facts.packages'
      tags:
      - CJIS-5.6.2.2
      - DISA-STIG-RHEL-08-010110
      - NIST-800-171-3.13.11
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.1
      - PCI-DSSv4-8.3.2
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - set_password_hashing_algorithm_logindefs

#### Rule Set PAM''s Password Hashing Algorithm - password-auth [ref]

The PAM system service can be configured to only store encrypted representations of passwords. In `/etc/pam.d/password-auth`, the `password` section of the file controls which PAM modules execute during a password change. Set the `pam_unix.so` module in the `password` section to include the argument `sha512`, as shown below:

    password    sufficient    pam_unix.so sha512 other arguments...

This will help ensure when local users change their passwords, hashes for the new passwords will be generated using the SHA-512 algorithm. This is the default.

Rationale:

Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kepy in plain text.
This setting ensures user and group account administration utilities are configured to store only encrypted representations of passwords. Additionally, the `crypt_style` configuration option ensures the use of a strong hashing algorithm that makes password cracking attacks more difficult.

Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_set_password_hashing_algorithm_passwordauth

Identifiers and References

References: BP28(R32), 1, 12, 15, 16, 5, 5.6.2.2, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.13.11, CCI-000196, CCI-000803, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0418, 1055, 1402, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(c), CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.2.1, SRG-OS-000073-GPOS-00041, SRG-OS-000120-GPOS-00061, 5.5.4, SV-230237r809276_rule

Remediation Shell script ⇲

    # Remediation is applicable only in certain platforms
    if rpm --quiet -q pam; then

    if [ -e "/etc/pam.d/password-auth" ] ; then
        PAM_FILE_PATH="/etc/pam.d/password-auth"
        if [ -f /usr/bin/authselect ]; then

            if ! authselect check; then
            echo "
            authselect integrity check failed. Remediation aborted!
            This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
            It is not recommended to manually edit the PAM files when authselect tool is available.
            In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
            exit 1
            fi

            CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
            # If not already in use, a custom profile is created preserving the enabled features.
            if [[ ! $CURRENT_PROFILE == custom/* ]]; then
                ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
                authselect create-profile hardening -b $CURRENT_PROFILE
                CURRENT_PROFILE="custom/hardening"

                authselect apply-changes -b --backup=before-hardening-custom-profile
                authselect select $CURRENT_PROFILE
                for feature in $ENABLED_FEATURES; do
                    authselect enable-feature $feature;
                done

                authselect apply-changes -b --backup=after-hardening-custom-profile
            fi
            PAM_FILE_NAME=$(basename "/etc/pam.d/password-auth")
            PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

            authselect apply-changes -b
        fi
        if ! grep -qP '^\s*password\s+'"sufficient"'\s+pam_unix.so\s*.*' "$PAM_FILE_PATH"; then
                # Line matching group + control + module was not found. Check group + module.
                if [ "$(grep -cP '^\s*password\s+.*\s+pam_unix.so\s*' "$PAM_FILE_PATH")" -eq 1 ]; then
                    # The control is updated only if one single line matches.
                    sed -i -E --follow-symlinks 's/^(\s*password\s+).*(\bpam_unix.so.*)/\1'"sufficient"' \2/' "$PAM_FILE_PATH"
                else
                    echo 'password    '"sufficient"'    pam_unix.so' >> "$PAM_FILE_PATH"
                fi
            fi
            # Check the option
            if ! grep -qP '^\s*password\s+'"sufficient"'\s+pam_unix.so\s*.*\ssha512\b' "$PAM_FILE_PATH"; then
                sed -i -E --follow-symlinks '/\s*password\s+'"sufficient"'\s+pam_unix.so.*/ s/$/ sha512/' "$PAM_FILE_PATH"
            fi
        if [ -f /usr/bin/authselect ]; then

            authselect apply-changes -b
        fi
    else
        echo "/etc/pam.d/password-auth was not found" >&2
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | configure

    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.6.2.2
      - DISA-STIG-RHEL-08-010160
      - NIST-800-171-3.13.11
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.1
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - set_password_hashing_algorithm_passwordauth

    - name: Set PAM's Password Hashing Algorithm - password-auth - Check if /etc/pam.d/password-auth
        file is present
      ansible.builtin.stat:
        path: /etc/pam.d/password-auth
      register: result_pam_file_present
      when: '"pam" in ansible_facts.packages'
      tags:
      - CJIS-5.6.2.2
      - DISA-STIG-RHEL-08-010160
      - NIST-800-171-3.13.11
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.1
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - set_password_hashing_algorithm_passwordauth

    - name: Set PAM's Password Hashing Algorithm - password-auth - Check the proper remediation
        for the system
      block:

      - name: Set PAM's Password Hashing Algorithm - password-auth - Define the PAM file
          to be edited as a local fact
        ansible.builtin.set_fact:
          pam_file_path: /etc/pam.d/password-auth

      - name: Set PAM's Password Hashing Algorithm - password-auth - Check if system relies
          on authselect tool
        ansible.builtin.stat:
          path: /usr/bin/authselect
        register: result_authselect_present

      - name: Set PAM's Password Hashing Algorithm - password-auth - Ensure authselect
          custom profile is used if authselect is present
        block:

        - name: Set PAM's Password Hashing Algorithm - password-auth - Check integrity
            of authselect current profile
          ansible.builtin.command:
            cmd: authselect check
          register: result_authselect_check_cmd
          changed_when: false
          failed_when: false

        - name: Set PAM's Password Hashing Algorithm - password-auth - Informative message
            based on the authselect integrity check result
          ansible.builtin.assert:
            that:
            - result_authselect_check_cmd.rc == 0
            fail_msg:
            - authselect integrity check failed. Remediation aborted!
            - This remediation could not be applied because an authselect profile was
              not selected or the selected profile is not intact.
            - It is not recommended to manually edit the PAM files when authselect tool
              is available.
            - In cases where the default authselect profile does not cover a specific
              demand, a custom authselect profile is recommended.
            success_msg:
            - authselect integrity check passed

        - name: Set PAM's Password Hashing Algorithm - password-auth - Get authselect
            current profile
          ansible.builtin.shell:
            cmd: authselect current -r | awk '{ print $1 }'
          register: result_authselect_profile
          changed_when: false
          when:
          - result_authselect_check_cmd is success

        - name: Set PAM's Password Hashing Algorithm - password-auth - Define the current
            authselect profile as a local fact
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is match("custom/")

        - name: Set PAM's Password Hashing Algorithm - password-auth - Define the new
            authselect custom profile as a local fact
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: custom/hardening
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is not match("custom/")

        - name: Set PAM's Password Hashing Algorithm - password-auth - Get authselect
            current features to also enable them in the custom profile
          ansible.builtin.shell:
            cmd: authselect current | tail -n+3 | awk '{ print $2 }'
          register: result_authselect_features
          changed_when: false
          when:
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")

        - name: Set PAM's Password Hashing Algorithm - password-auth - Check if any custom
            profile with the same name was already created
          ansible.builtin.stat:
            path: /etc/authselect/{{ authselect_custom_profile }}
          register: result_authselect_custom_profile_present
          changed_when: false
          when:
          - authselect_current_profile is not match("custom/")

        - name: Set PAM's Password Hashing Algorithm - password-auth - Create an authselect
            custom profile based on the current profile
          ansible.builtin.command:
            cmd: authselect create-profile hardening -b {{ authselect_current_profile
              }}
          when:
          - result_authselect_check_cmd is success
          - authselect_current_profile is not match("custom/")
          - not result_authselect_custom_profile_present.stat.exists

        - name: Set PAM's Password Hashing Algorithm - password-auth - Ensure authselect
            changes are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: Set PAM's Password Hashing Algorithm - password-auth - Ensure the authselect
            custom profile is selected
          ansible.builtin.command:
            cmd: authselect select {{ authselect_custom_profile }}
          register: result_pam_authselect_select_profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: Set PAM's Password Hashing Algorithm - password-auth - Restore the authselect
            features in the custom profile
          ansible.builtin.command:
            cmd: authselect enable-feature {{ item }}
          loop: '{{ result_authselect_features.stdout_lines }}'
          register: result_pam_authselect_restore_features
          when:
          - result_authselect_profile is not skipped
          - result_authselect_features is not skipped
          - result_pam_authselect_select_profile is not skipped

        - name: Set PAM's Password Hashing Algorithm - password-auth - Ensure authselect
            changes are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - result_pam_authselect_restore_features is not skipped

        - name: Set PAM's Password Hashing Algorithm - password-auth - Change the PAM
            file to be edited according to the custom authselect profile
          ansible.builtin.set_fact:
            pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
              | basename }}
        when:
        - result_authselect_present.stat.exists

      - name: Set PAM's Password Hashing Algorithm - password-auth - Check if expected
          PAM module line is present in {{ pam_file_path }}
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          regexp: ^\s*password\s+{{ 'sufficient' | regex_escape() }}\s+pam_unix.so\s*.*
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_line_present

      - name: Set PAM's Password Hashing Algorithm - password-auth - Include or update
          the PAM module line in {{ pam_file_path }}
        block:

        - name: Set PAM's Password Hashing Algorithm - password-auth - Check if required
            PAM module line is present in {{ pam_file_path }} with different control
          ansible.builtin.lineinfile:
            path: '{{ pam_file_path }}'
            regexp: ^\s*password\s+.*\s+pam_unix.so\s*
            state: absent
          check_mode: true
          changed_when: false
          register: result_pam_line_other_control_present

        - name: Set PAM's Password Hashing Algorithm - password-auth - Ensure the correct
            control for the required PAM module line in {{ pam_file_path }}
          ansible.builtin.replace:
            dest: '{{ pam_file_path }}'
            regexp: ^(\s*password\s+).*(\bpam_unix.so.*)
            replace: \1sufficient \2
          register: result_pam_module_edit
          when:
          - result_pam_line_other_control_present.found == 1

        - name: Set PAM's Password Hashing Algorithm - password-auth - Ensure the required
            PAM module line is included in {{ pam_file_path }}
          ansible.builtin.lineinfile:
            dest: '{{ pam_file_path }}'
            line: password    sufficient    pam_unix.so
          register: result_pam_module_add
          when:
          - result_pam_line_other_control_present.found == 0 or result_pam_line_other_control_present.found
            > 1

        - name: Set PAM's Password Hashing Algorithm - password-auth - Ensure authselect
            changes are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b
          when:
          - result_authselect_present is defined
          - result_authselect_present.stat.exists
          - |-
            (result_pam_module_add is defined and result_pam_module_add.changed)
             or (result_pam_module_edit is defined and result_pam_module_edit.changed)
        when:
        - result_pam_line_present.found is defined
        - result_pam_line_present.found == 0

      - name: Set PAM's Password Hashing Algorithm - password-auth - Check if the required
          PAM module option is present in {{ pam_file_path }}
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          regexp: ^\s*password\s+{{ 'sufficient' | regex_escape() }}\s+pam_unix.so\s*.*\ssha512\b
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_module_sha512_option_present

      - name: Set PAM's Password Hashing Algorithm - password-auth - Ensure the "sha512"
          PAM option for "pam_unix.so" is included in {{ pam_file_path }}
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          backrefs: true
          regexp: ^(\s*password\s+{{ 'sufficient' | regex_escape() }}\s+pam_unix.so.*)
          line: \1 sha512
          state: present
        register: result_pam_sha512_add
        when:
        - result_pam_module_sha512_option_present.found == 0

      - name: Set PAM's Password Hashing Algorithm - password-auth - Ensure authselect
          changes are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b
        when:
        - result_authselect_present.stat.exists
        - |-
          (result_pam_sha512_add is defined and result_pam_sha512_add.changed)
           or (result_pam_sha512_edit is defined and result_pam_sha512_edit.changed)
      when:
      - '"pam" in ansible_facts.packages'
      - result_pam_file_present.stat.exists
      tags:
      - CJIS-5.6.2.2
      - DISA-STIG-RHEL-08-010160
      - NIST-800-171-3.13.11
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.1
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - set_password_hashing_algorithm_passwordauth

#### Rule Set PAM''s Password Hashing Algorithm [ref]

The PAM system service can be configured to only store encrypted representations of passwords. In "/etc/pam.d/system-auth", the `password` section of the file controls which PAM modules execute during a password change. Set the `pam_unix.so` module in the `password` section to include the argument `sha512`, as shown below:

    password    sufficient    pam_unix.so sha512 other arguments...

This will help ensure when local users change their passwords, hashes for the new passwords will be generated using the SHA-512 algorithm. This is the default.

Rationale:

Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kepy in plain text.
This setting ensures user and group account administration utilities are configured to store only encrypted representations of passwords. Additionally, the `crypt_style` configuration option ensures the use of a strong hashing algorithm that makes password cracking attacks more difficult.

Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_set_password_hashing_algorithm_systemauth

Identifiers and References

References: BP28(R32), 1, 12, 15, 16, 5, 5.6.2.2, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.13.11, CCI-000196, CCI-000803, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0418, 1055, 1402, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(c), CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.2.1, 8.3.2, SRG-OS-000073-GPOS-00041, SRG-OS-000120-GPOS-00061, 5.5.4, SV-244524r809331_rule

Remediation Shell script ⇲

    # Remediation is applicable only in certain platforms
    if rpm --quiet -q pam; then

    if [ -e "/etc/pam.d/system-auth" ] ; then
        PAM_FILE_PATH="/etc/pam.d/system-auth"
        if [ -f /usr/bin/authselect ]; then

            if ! authselect check; then
            echo "
            authselect integrity check failed. Remediation aborted!
            This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
            It is not recommended to manually edit the PAM files when authselect tool is available.
            In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
            exit 1
            fi

            CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
            # If not already in use, a custom profile is created preserving the enabled features.
            if [[ ! $CURRENT_PROFILE == custom/* ]]; then
                ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
                authselect create-profile hardening -b $CURRENT_PROFILE
                CURRENT_PROFILE="custom/hardening"

                authselect apply-changes -b --backup=before-hardening-custom-profile
                authselect select $CURRENT_PROFILE
                for feature in $ENABLED_FEATURES; do
                    authselect enable-feature $feature;
                done

                authselect apply-changes -b --backup=after-hardening-custom-profile
            fi
            PAM_FILE_NAME=$(basename "/etc/pam.d/system-auth")
            PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

            authselect apply-changes -b
        fi
        if ! grep -qP '^\s*password\s+'"sufficient"'\s+pam_unix.so\s*.*' "$PAM_FILE_PATH"; then
                # Line matching group + control + module was not found. Check group + module.
                if [ "$(grep -cP '^\s*password\s+.*\s+pam_unix.so\s*' "$PAM_FILE_PATH")" -eq 1 ]; then
                    # The control is updated only if one single line matches.
                    sed -i -E --follow-symlinks 's/^(\s*password\s+).*(\bpam_unix.so.*)/\1'"sufficient"' \2/' "$PAM_FILE_PATH"
                else
                    echo 'password    '"sufficient"'    pam_unix.so' >> "$PAM_FILE_PATH"
                fi
            fi
            # Check the option
            if ! grep -qP '^\s*password\s+'"sufficient"'\s+pam_unix.so\s*.*\ssha512\b' "$PAM_FILE_PATH"; then
                sed -i -E --follow-symlinks '/\s*password\s+'"sufficient"'\s+pam_unix.so.*/ s/$/ sha512/' "$PAM_FILE_PATH"
            fi
        if [ -f /usr/bin/authselect ]; then

            authselect apply-changes -b
        fi
    else
        echo "/etc/pam.d/system-auth was not found" >&2
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | configure

    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.6.2.2
      - DISA-STIG-RHEL-08-010159
      - NIST-800-171-3.13.11
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.1
      - PCI-DSSv4-8.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - set_password_hashing_algorithm_systemauth

    - name: Set PAM's Password Hashing Algorithm - Check if /etc/pam.d/system-auth file
        is present
      ansible.builtin.stat:
        path: /etc/pam.d/system-auth
      register: result_pam_file_present
      when: '"pam" in ansible_facts.packages'
      tags:
      - CJIS-5.6.2.2
      - DISA-STIG-RHEL-08-010159
      - NIST-800-171-3.13.11
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.1
      - PCI-DSSv4-8.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - set_password_hashing_algorithm_systemauth

    - name: Set PAM's Password Hashing Algorithm - Check the proper remediation for the
        system
      block:

      - name: Set PAM's Password Hashing Algorithm - Define the PAM file to be edited
          as a local fact
        ansible.builtin.set_fact:
          pam_file_path: /etc/pam.d/system-auth

      - name: Set PAM's Password Hashing Algorithm - Check if system relies on authselect
          tool
        ansible.builtin.stat:
          path: /usr/bin/authselect
        register: result_authselect_present

      - name: Set PAM's Password Hashing Algorithm - Ensure authselect custom profile
          is used if authselect is present
        block:

        - name: Set PAM's Password Hashing Algorithm - Check integrity of authselect current
            profile
          ansible.builtin.command:
            cmd: authselect check
          register: result_authselect_check_cmd
          changed_when: false
          failed_when: false

        - name: Set PAM's Password Hashing Algorithm - Informative message based on the
            authselect integrity check result
          ansible.builtin.assert:
            that:
            - result_authselect_check_cmd.rc == 0
            fail_msg:
            - authselect integrity check failed. Remediation aborted!
            - This remediation could not be applied because an authselect profile was
              not selected or the selected profile is not intact.
            - It is not recommended to manually edit the PAM files when authselect tool
              is available.
            - In cases where the default authselect profile does not cover a specific
              demand, a custom authselect profile is recommended.
            success_msg:
            - authselect integrity check passed

        - name: Set PAM's Password Hashing Algorithm - Get authselect current profile
          ansible.builtin.shell:
            cmd: authselect current -r | awk '{ print $1 }'
          register: result_authselect_profile
          changed_when: false
          when:
          - result_authselect_check_cmd is success

        - name: Set PAM's Password Hashing Algorithm - Define the current authselect profile
            as a local fact
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is match("custom/")

        - name: Set PAM's Password Hashing Algorithm - Define the new authselect custom
            profile as a local fact
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: custom/hardening
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is not match("custom/")

        - name: Set PAM's Password Hashing Algorithm - Get authselect current features
            to also enable them in the custom profile
          ansible.builtin.shell:
            cmd: authselect current | tail -n+3 | awk '{ print $2 }'
          register: result_authselect_features
          changed_when: false
          when:
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")

        - name: Set PAM's Password Hashing Algorithm - Check if any custom profile with
            the same name was already created
          ansible.builtin.stat:
            path: /etc/authselect/{{ authselect_custom_profile }}
          register: result_authselect_custom_profile_present
          changed_when: false
          when:
          - authselect_current_profile is not match("custom/")

        - name: Set PAM's Password Hashing Algorithm - Create an authselect custom profile
            based on the current profile
          ansible.builtin.command:
            cmd: authselect create-profile hardening -b {{ authselect_current_profile
              }}
          when:
          - result_authselect_check_cmd is success
          - authselect_current_profile is not match("custom/")
          - not result_authselect_custom_profile_present.stat.exists

        - name: Set PAM's Password Hashing Algorithm - Ensure authselect changes are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: Set PAM's Password Hashing Algorithm - Ensure the authselect custom profile
            is selected
          ansible.builtin.command:
            cmd: authselect select {{ authselect_custom_profile }}
          register: result_pam_authselect_select_profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: Set PAM's Password Hashing Algorithm - Restore the authselect features
            in the custom profile
          ansible.builtin.command:
            cmd: authselect enable-feature {{ item }}
          loop: '{{ result_authselect_features.stdout_lines }}'
          register: result_pam_authselect_restore_features
          when:
          - result_authselect_profile is not skipped
          - result_authselect_features is not skipped
          - result_pam_authselect_select_profile is not skipped

        - name: Set PAM's Password Hashing Algorithm - Ensure authselect changes are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - result_pam_authselect_restore_features is not skipped

        - name: Set PAM's Password Hashing Algorithm - Change the PAM file to be edited
            according to the custom authselect profile
          ansible.builtin.set_fact:
            pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
              | basename }}
        when:
        - result_authselect_present.stat.exists

      - name: Set PAM's Password Hashing Algorithm - Check if expected PAM module line
          is present in {{ pam_file_path }}
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          regexp: ^\s*password\s+{{ 'sufficient' | regex_escape() }}\s+pam_unix.so\s*.*
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_line_present

      - name: Set PAM's Password Hashing Algorithm - Include or update the PAM module
          line in {{ pam_file_path }}
        block:

        - name: Set PAM's Password Hashing Algorithm - Check if required PAM module line
            is present in {{ pam_file_path }} with different control
          ansible.builtin.lineinfile:
            path: '{{ pam_file_path }}'
            regexp: ^\s*password\s+.*\s+pam_unix.so\s*
            state: absent
          check_mode: true
          changed_when: false
          register: result_pam_line_other_control_present

        - name: Set PAM's Password Hashing Algorithm - Ensure the correct control for
            the required PAM module line in {{ pam_file_path }}
          ansible.builtin.replace:
            dest: '{{ pam_file_path }}'
            regexp: ^(\s*password\s+).*(\bpam_unix.so.*)
            replace: \1sufficient \2
          register: result_pam_module_edit
          when:
          - result_pam_line_other_control_present.found == 1

        - name: Set PAM's Password Hashing Algorithm - Ensure the required PAM module
            line is included in {{ pam_file_path }}
          ansible.builtin.lineinfile:
            dest: '{{ pam_file_path }}'
            line: password    sufficient    pam_unix.so
          register: result_pam_module_add
          when:
          - result_pam_line_other_control_present.found == 0 or result_pam_line_other_control_present.found
            > 1

        - name: Set PAM's Password Hashing Algorithm - Ensure authselect changes are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b
          when:
          - result_authselect_present is defined
          - result_authselect_present.stat.exists
          - |-
            (result_pam_module_add is defined and result_pam_module_add.changed)
             or (result_pam_module_edit is defined and result_pam_module_edit.changed)
        when:
        - result_pam_line_present.found is defined
        - result_pam_line_present.found == 0

      - name: Set PAM's Password Hashing Algorithm - Check if the required PAM module
          option is present in {{ pam_file_path }}
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          regexp: ^\s*password\s+{{ 'sufficient' | regex_escape() }}\s+pam_unix.so\s*.*\ssha512\b
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_module_sha512_option_present

      - name: Set PAM's Password Hashing Algorithm - Ensure the "sha512" PAM option for
          "pam_unix.so" is included in {{ pam_file_path }}
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          backrefs: true
          regexp: ^(\s*password\s+{{ 'sufficient' | regex_escape() }}\s+pam_unix.so.*)
          line: \1 sha512
          state: present
        register: result_pam_sha512_add
        when:
        - result_pam_module_sha512_option_present.found == 0

      - name: Set PAM's Password Hashing Algorithm - Ensure authselect changes are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b
        when:
        - result_authselect_present.stat.exists
        - |-
          (result_pam_sha512_add is defined and result_pam_sha512_add.changed)
           or (result_pam_sha512_edit is defined and result_pam_sha512_edit.changed)
      when:
      - '"pam" in ansible_facts.packages'
      - result_pam_file_present.stat.exists
      tags:
      - CJIS-5.6.2.2
      - DISA-STIG-RHEL-08-010159
      - NIST-800-171-3.13.11
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.1
      - PCI-DSSv4-8.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - set_password_hashing_algorithm_systemauth

Group Protect Physical Console Access Group contains 1 rule
[ref] It is impossible to fully protect a system from an attacker with physical access, so securing the space in which the system is located should be considered a necessary step. However, there are some steps which, if taken, make it more difficult for an attacker to quickly or undetectably modify a system from its console.

#### Rule Require Authentication for Single User Mode [ref]

Single-user mode is intended as a system recovery method, providing a single user root access to the system by providing a boot option at startup. By default, single-user mode is protected by requiring a password and is set in `/usr/lib/systemd/system/rescue.service`.
Rationale: | This prevents attackers with physical access from trivially bypassing security on the machine and gaining root access. Such accesses are further prevented by configuring the bootloader password.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_require_singleuser_auth

Identifiers and References

References: 1, 11, 12, 14, 15, 16, 18, 3, 5, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.06, DSS06.10, 3.1.1, 3.4.5, CCI-000213, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, IA-2, AC-3, CM-6(a), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.PT-3, FIA_UAU.1, SRG-OS-000080-GPOS-00048, 1.4.3, SV-230236r743928_rule

Remediation Shell script ⇲

    # Remediation is applicable only in certain platforms
    if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

    service_file="/usr/lib/systemd/system/rescue.service"

    sulogin="/usr/lib/systemd/systemd-sulogin-shell rescue"

    if grep "^ExecStart=.*" "$service_file" ; then
        sed -i "s%^ExecStart=.*%ExecStart=-$sulogin%" "$service_file"
    else
        echo "ExecStart=-$sulogin" >> "$service_file"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    - name: Require single user mode password
      lineinfile:
        create: true
        dest: /usr/lib/systemd/system/rescue.service
        regexp: ^#?ExecStart=
        line: ExecStart=-/usr/lib/systemd/systemd-sulogin-shell rescue
      when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - DISA-STIG-RHEL-08-010151
      - NIST-800-171-3.1.1
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-3
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-2
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - require_singleuser_auth
      - restrict_strategy

Group Protect Accounts by Restricting Password-Based Login Group contains 3 groups and 6 rules

[ref] Conventionally, Unix shell accounts are accessed by providing a username and password to a login program, which tests these values for correctness using the `/etc/passwd` and `/etc/shadow` files. Password-based login is vulnerable to guessing of weak passwords, and to sniffing and man-in-the-middle attacks against passwords entered over a network or at an insecure console. Therefore, mechanisms for accessing accounts by entering usernames and passwords should be restricted to those which are operationally necessary.

Group Set Password Expiration Parameters Group contains 2 rules

[ref] The file `/etc/login.defs` controls several password-related settings. Programs such as `passwd`, `su`, and `login` consult `/etc/login.defs` to determine behavior with regard to password aging, expiration warnings, and length. See the man page `login.defs(5)` for more information.
Users should be forced to change their passwords, in order to decrease the utility of compromised passwords. However, the need to change passwords often should be balanced against the risk that users will reuse or write down passwords if forced to change them too often. Forcing password changes every 90-360 days, depending on the environment, is recommended. Set the appropriate value as `PASS_MAX_DAYS` and apply it to existing accounts with the `-M` flag.
The `PASS_MIN_DAYS` (`-m`) setting prevents password changes for 7 days after the first change, to discourage password cycling. If you use this setting, train users to contact an administrator for an emergency password change in case a new password becomes compromised. The `PASS_WARN_AGE` (`-W`) setting gives users 7 days of warnings at login time that their passwords are about to expire.
For example, for each existing human user USER, expiration parameters could be adjusted to a 180 day maximum password age, 7 day minimum password age, and 7 day warning period with the following command:

    $ sudo chage -M 180 -m 7 -W 7 USER

#### Rule Set Password Minimum Age [ref]

To specify password minimum age for new accounts, edit the file `/etc/login.defs` and add or correct the following line:

    PASS_MIN_DAYS 7

A value of 1 day is considered sufficient for many environments. The DoD requirement is 1. The profile requirement is `7`.

Rationale:

Enforcing a minimum password lifetime helps to prevent repeated password changes to defeat the password reuse or history enforcement requirement. If users are allowed to immediately and continually change their password, then the password could be repeatedly changed in a short period of time to defeat the organization's policy regarding password reuse.
Setting the minimum password age protects against users cycling back to a favorite password after satisfying the password reuse requirement.

Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_minimum_age_login_defs

Identifiers and References

References: 1, 12, 15, 16, 5, 5.6.2.1.1, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.5.8, CCI-000198, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0418, 1055, 1402, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(f), IA-5(1)(d), CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, SRG-OS-000075-GPOS-00043, 5.6.1.2, SV-230365r858727_rule

Remediation Shell script ⇲

    # Remediation is applicable only in certain platforms
    if rpm --quiet -q shadow-utils; then

    var_accounts_minimum_age_login_defs='7'

    grep -q ^PASS_MIN_DAYS /etc/login.defs && \
      sed -i "s/PASS_MIN_DAYS.*/PASS_MIN_DAYS     $var_accounts_minimum_age_login_defs/g" /etc/login.defs
    if ! [ $? -eq 0 ]; then
        echo "PASS_MIN_DAYS      $var_accounts_minimum_age_login_defs" >> /etc/login.defs
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.6.2.1.1
      - DISA-STIG-RHEL-08-020190
      - NIST-800-171-3.5.8
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(d)
      - NIST-800-53-IA-5(f)
      - accounts_minimum_age_login_defs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_accounts_minimum_age_login_defs # promote to variable
      set_fact:
        var_accounts_minimum_age_login_defs: !!str 7
      tags:
        - always

    - name: Set Password Minimum Age
      lineinfile:
        create: true
        dest: /etc/login.defs
        regexp: ^#?PASS_MIN_DAYS
        line: PASS_MIN_DAYS {{ var_accounts_minimum_age_login_defs }}
      when: '"shadow-utils" in ansible_facts.packages'
      tags:
      - CJIS-5.6.2.1.1
      - DISA-STIG-RHEL-08-020190
      - NIST-800-171-3.5.8
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(d)
      - NIST-800-53-IA-5(f)
      - accounts_minimum_age_login_defs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

#### Rule Set Password Warning Age [ref]

To specify how many days prior to password expiration that a warning will be issued to users, edit the file `/etc/login.defs` and add or correct the following line:

    PASS_WARN_AGE 7

The DoD requirement is 7. The profile requirement is `7`.

Rationale: | Setting the password warning age enables users to make the change at a practical time.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_warn_age_login_defs

Identifiers and References

References: 1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.5.8, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2, 0418, 1055, 1402, A.12.4.1, A.12.4.3, A.18.1.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, IA-5(f), IA-5(1)(d), CM-6(a), DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, Req-8.2.4, 8.3.9, 5.6.1.3

Remediation Shell script ⇲

    # Remediation is applicable only in certain platforms
    if rpm --quiet -q shadow-utils; then

    var_accounts_password_warn_age_login_defs='7'

    grep -q ^PASS_WARN_AGE /etc/login.defs && \
    sed -i "s/PASS_WARN_AGE.*/PASS_WARN_AGE\t$var_accounts_password_warn_age_login_defs/g" /etc/login.defs
    if ! [ $? -eq 0 ]
    then
      echo -e "PASS_WARN_AGE\t$var_accounts_password_warn_age_login_defs" >> /etc/login.defs
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.5.8
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(d)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.4
      - PCI-DSSv4-8.3.9
      - accounts_password_warn_age_login_defs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_accounts_password_warn_age_login_defs # promote to variable
      set_fact:
        var_accounts_password_warn_age_login_defs: !!str 7
      tags:
        - always

    - name: Set Password Warning Age
      lineinfile:
        dest: /etc/login.defs
        regexp: ^PASS_WARN_AGE *[0-9]*
        state: present
        line: PASS_WARN_AGE        {{ var_accounts_password_warn_age_login_defs }}
        create: true
      when: '"shadow-utils" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.5.8
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(d)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.4
      - PCI-DSSv4-8.3.9
      - accounts_password_warn_age_login_defs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

Group Verify Proper Storage and Existence of Password Hashes Group contains 2 rules

[ref] By default, password hashes for local accounts are stored in the second field (colon-separated) in `/etc/shadow`. This file should be readable only by processes running with root credentials, preventing users from casually accessing others' password hashes and attempting to crack them. However, it remains possible to misconfigure the system and store password hashes in world-readable files such as `/etc/passwd`, or to even store passwords themselves in plaintext on the system. Using system-provided tools for password change/creation should allow administrators to avoid such misconfiguration.

#### Rule Verify All Account Password Hashes are Shadowed [ref]

If any password hashes are stored in `/etc/passwd` (in the second field, instead of an `x` or `*`), the cause of this misconfiguration should be investigated. The account should have its password reset and the hash should be properly stored, or the account should be deleted entirely.
Rationale: | The hashes for all user account passwords should be stored in the file `/etc/shadow` and never in `/etc/passwd`, which is readable by all users.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_all_shadowed

Identifiers and References

References: 1, 12, 15, 16, 5, 5.5.2, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.5.10, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 1410, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(h), CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.2.1, 8.3.2

#### Rule Prevent Login to Accounts With Empty Password [ref]

If an account is configured for password authentication but does not have an assigned password, it may be possible to log into the account without authentication. Remove any instances of the `nullok` in `/etc/pam.d/system-auth` and `/etc/pam.d/password-auth` to prevent logins with empty passwords.
Warning: If the system relies on `authselect` tool to manage PAM settings, the remediation will also use `authselect` tool. However, if any manual modification was made in PAM files, the `authselect` integrity check will fail and the remediation will be aborted in order to preserve intentional changes. In this case, an informative message will be shown in the remediation report. Note that this rule is not applicable for systems running within a container. Having user with empty password within a container is not considered a risk, because it should not be possible to directly login into a container anyway.

Rationale: | If an account has an empty password, anyone could log in and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments.
Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_no_empty_passwords

Identifiers and References

References: 1, 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2, APO01.06, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.10, 3.1.1, 3.1.5, CCI-000366, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.18.1.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, IA-5(1)(a), IA-5(c), CM-6(a), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5, FIA_UAU.1, Req-8.2.3, 8.3.1, SRG-OS-000480-GPOS-00227, 5.4.1, SV-244540r743869_rule, SV-244541r743872_rule

Remediation Shell script ⇲

Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | configure

    # Remediation is applicable only in certain platforms
    if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

    if [ -f /usr/bin/authselect ]; then
        if ! authselect check; then
    echo "
    authselect integrity check failed. Remediation aborted!
    This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
    It is not recommended to manually edit the PAM files when authselect tool is available.
    In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
    exit 1
    fi
    authselect enable-feature without-nullok

    authselect apply-changes -b
    else

    if grep -qP '^\s*auth\s+'"sufficient"'\s+pam_unix.so\s.*\bnullok\b' "/etc/pam.d/system-auth"; then
        sed -i -E --follow-symlinks 's/(.*auth.*'"sufficient"'.*pam_unix.so.*)\snullok=?[[:alnum:]]*(.*)/\1\2/g' "/etc/pam.d/system-auth"
    fi

    if grep -qP '^\s*password\s+'"sufficient"'\s+pam_unix.so\s.*\bnullok\b' "/etc/pam.d/system-auth"; then
        sed -i -E --follow-symlinks 's/(.*password.*'"sufficient"'.*pam_unix.so.*)\snullok=?[[:alnum:]]*(.*)/\1\2/g' "/etc/pam.d/system-auth"
    fi

    if grep -qP '^\s*auth\s+'"sufficient"'\s+pam_unix.so\s.*\bnullok\b' "/etc/pam.d/password-auth"; then
        sed -i -E --follow-symlinks 's/(.*auth.*'"sufficient"'.*pam_unix.so.*)\snullok=?[[:alnum:]]*(.*)/\1\2/g' "/etc/pam.d/password-auth"
    fi

    if grep -qP '^\s*password\s+'"sufficient"'\s+pam_unix.so\s.*\bnullok\b' "/etc/pam.d/password-auth"; then
        sed -i -E --follow-symlinks 's/(.*password.*'"sufficient"'.*pam_unix.so.*)\snullok=?[[:alnum:]]*(.*)/\1\2/g' "/etc/pam.d/password-auth"
    fi
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | configure

    - name: Prevent Login to Accounts With Empty Password - Check if system relies on
        authselect
      ansible.builtin.stat:
        path: /usr/bin/authselect
      register: result_authselect_present
      when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - CJIS-5.5.2
      - DISA-STIG-RHEL-08-020331
      - DISA-STIG-RHEL-08-020332
      - NIST-800-171-3.1.1
      - NIST-800-171-3.1.5
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(a)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.3
      - PCI-DSSv4-8.3.1
      - configure_strategy
      - high_severity
      - low_complexity
      - medium_disruption
      - no_empty_passwords
      - no_reboot_needed

    - name: Prevent Login to Accounts With Empty Password - Remediate using authselect
      block:

      - name: Prevent Login to Accounts With Empty Password - Check integrity of authselect
          current profile
        ansible.builtin.command:
          cmd: authselect check
        register: result_authselect_check_cmd
        changed_when: false
        failed_when: false

      - name: Prevent Login to Accounts With Empty Password - Informative message based
          on the authselect integrity check result
        ansible.builtin.assert:
          that:
          - result_authselect_check_cmd.rc == 0
          fail_msg:
          - authselect integrity check failed. Remediation aborted!
          - This remediation could not be applied because an authselect profile was not
            selected or the selected profile is not intact.
          - It is not recommended to manually edit the PAM files when authselect tool
            is available.
          - In cases where the default authselect profile does not cover a specific demand,
            a custom authselect profile is recommended.
          success_msg:
          - authselect integrity check passed

      - name: Prevent Login to Accounts With Empty Password - Get authselect current features
        ansible.builtin.shell:
          cmd: authselect current | tail -n+3 | awk '{ print $2 }'
        register: result_authselect_features
        changed_when: false
        when:
        - result_authselect_check_cmd is success

      - name: Prevent Login to Accounts With Empty Password - Ensure "without-nullok"
          feature is enabled using authselect tool
        ansible.builtin.command:
          cmd: authselect enable-feature without-nullok
        register: result_authselect_enable_feature_cmd
        when:
        - result_authselect_check_cmd is success
        - result_authselect_features.stdout is not search("without-nullok")

      - name: Prevent Login to Accounts With Empty Password - Ensure authselect changes
          are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b
        when:
        - result_authselect_enable_feature_cmd is not skipped
        - result_authselect_enable_feature_cmd is success
      when:
      - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      - result_authselect_present.stat.exists
      tags:
      - CJIS-5.5.2
      - DISA-STIG-RHEL-08-020331
      - DISA-STIG-RHEL-08-020332
      - NIST-800-171-3.1.1
      - NIST-800-171-3.1.5
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(a)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.3
      - PCI-DSSv4-8.3.1
      - configure_strategy
      - high_severity
      - low_complexity
      - medium_disruption
      - no_empty_passwords
      - no_reboot_needed

    - name: Prevent Login to Accounts With Empty Password - Remediate directly editing
        PAM files
      ansible.builtin.replace:
        dest: '{{ item }}'
        regexp: nullok
      loop:
      - /etc/pam.d/system-auth
      - /etc/pam.d/password-auth
      when:
      - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      - not result_authselect_present.stat.exists
      tags:
      - CJIS-5.5.2
      - DISA-STIG-RHEL-08-020331
      - DISA-STIG-RHEL-08-020332
      - NIST-800-171-3.1.1
      - NIST-800-171-3.1.5
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(a)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.3
      - PCI-DSSv4-8.3.1
      - configure_strategy
      - high_severity
      - low_complexity
      - medium_disruption
      - no_empty_passwords
      - no_reboot_needed

Remediation Kubernetes snippet ⇲

    ---
    apiVersion: machineconfiguration.openshift.io/v1
    kind: MachineConfig
    spec:
      config:
        ignition:
          version: 3.1.0
        storage:
          files:
          - contents:
              source: data:,%23%20Generated%20by%20authselect%20on%20Sat%20Oct%2027%2014%3A59%3A36%202018%0A%23%20Do%20not%20modify%20this%20file%20manually.%0A%0Aauth%20%20%20%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_env.so%0Aauth%20%20%20%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_faildelay.so%20delay%3D2000000%0Aauth%20%20%20%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_fprintd.so%0Aauth%20%20%20%20%20%20%20%20%5Bdefault%3D1%20ignore%3Dignore%20success%3Dok%5D%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20uid%20%3E%3D%201000%20quiet%0Aauth%20%20%20%20%20%20%20%20%5Bdefault%3D1%20ignore%3Dignore%20success%3Dok%5D%20%20%20%20%20%20%20%20%20pam_localuser.so%0Aauth%20%20%20%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%20try_first_pass%0Aauth%20%20%20%20%20%20%20%20requisite%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20uid%20%3E%3D%201000%20quiet_success%0Aauth%20%20%20%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_sss.so%20forward_pass%0Aauth%20%20%20%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_deny.so%0A%0Aaccount%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%0Aaccount%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_localuser.so%0Aaccount%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20uid%20%3C%201000%20quiet%0Aaccount%20%20%20%20%20%5Bdefault%3Dbad%20success%3Dok%20user_unknown%3Dignore%5D%20pam_sss.so%0Aaccount%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_permit.so%0A%0Apassword%20%20%20%20requisite%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_pwquality.so%20try_first_pass%20local_users_only%0Apassword%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%20sha512%20shadow%20try_first_pass%20use_authtok%0Apassword%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_sss.so%20use_authtok%0Apassword%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_deny.so%0A%0Asession%20%20%20%20%20optional%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_keyinit.so%20revoke%0Asession%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_limits.so%0A-session%20%20%20%20optional%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_systemd.so%0Asession%20%20%20%20%20%5Bsuccess%3D1%20default%3Dignore%5D%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20service%20in%20crond%20quiet%20use_uid%0Asession%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%0Asession%20%20%20%20%20optional%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_sss.so%0A
            mode: 0644
            path: /etc/pam.d/password-auth
            overwrite: true
          - contents:
              source: data:,%23%20Generated%20by%20authselect%20on%20Sat%20Oct%2027%2014%3A59%3A36%202018%0A%23%20Do%20not%20modify%20this%20file%20manually.%0A%0Aauth%20%20%20%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_env.so%0Aauth%20%20%20%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_faildelay.so%20delay%3D2000000%0Aauth%20%20%20%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_fprintd.so%0Aauth%20%20%20%20%20%20%20%20%5Bdefault%3D1%20ignore%3Dignore%20success%3Dok%5D%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20uid%20%3E%3D%201000%20quiet%0Aauth%20%20%20%20%20%20%20%20%5Bdefault%3D1%20ignore%3Dignore%20success%3Dok%5D%20%20%20%20%20%20%20%20%20pam_localuser.so%0Aauth%20%20%20%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%20try_first_pass%0Aauth%20%20%20%20%20%20%20%20requisite%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20uid%20%3E%3D%201000%20quiet_success%0Aauth%20%20%20%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_sss.so%20forward_pass%0Aauth%20%20%20%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_deny.so%0A%0Aaccount%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%0Aaccount%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_localuser.so%0Aaccount%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20uid%20%3C%201000%20quiet%0Aaccount%20%20%20%20%20%5Bdefault%3Dbad%20success%3Dok%20user_unknown%3Dignore%5D%20pam_sss.so%0Aaccount%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_permit.so%0A%0Apassword%20%20%20%20requisite%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_pwquality.so%20try_first_pass%20local_users_only%0Apassword%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%20sha512%20shadow%20try_first_pass%20use_authtok%0Apassword%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_sss.so%20use_authtok%0Apassword%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_deny.so%0A%0Asession%20%20%20%20%20optional%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_keyinit.so%20revoke%0Asession%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_limits.so%0A-session%20%20%20%20optional%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_systemd.so%0Asession%20%20%20%20%20%5Bsuccess%3D1%20default%3Dignore%5D%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20service%20in%20crond%20quiet%20use_uid%0Asession%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%0Asession%20%20%20%20%20optional%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_sss.so%0A
            mode: 0644
            path: /etc/pam.d/system-auth
            overwrite: true

Group Restrict Root Logins Group contains 2 rules

[ref] Direct root logins should be allowed only for emergency use. In normal situations, the administrator should access the system via a unique unprivileged account, and then use `su` or `sudo` to execute privileged commands. Discouraging administrators from accessing the root account directly ensures an audit trail in organizations with multiple administrators. Locking down the channels through which root can connect directly also reduces opportunities for password-guessing against the root account. The `login` program uses the file `/etc/securetty` to determine which interfaces should allow root logins. The virtual devices `/dev/console` and `/dev/tty*` represent the system consoles (accessible via the Ctrl-Alt-F1 through Ctrl-Alt-F6 keyboard sequences on a default installation). The default securetty file also contains `/dev/vc/*`. These are likely to be deprecated in most environments, but may be retained for compatibility. Root should also be prohibited from connecting via network protocols. Other sections of this document include guidance describing how to prevent root from logging in via SSH.

#### Rule Verify Only Root Has UID 0 [ref]

If any account other than root has a UID of 0, this misconfiguration should be investigated and the accounts other than root should be removed or have their UID changed. If the account is associated with system commands or applications the UID should be changed to one greater than "0" but less than "1000." Otherwise assign a UID greater than "1000" that has not already been assigned.
Rationale: | An account has root authority if it has a UID of 0. Multiple accounts with a UID of 0 afford more opportunity for potential intruders to guess a password for a privileged account. Proper configuration of sudo is recommended to afford multiple system administrators access to root privileges in an accountable manner.
Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_no_uid_except_zero

Identifiers and References

References: 1, 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.10, 3.1.1, 3.1.5, CCI-000366, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.18.1.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, IA-2, AC-6(5), IA-4(b), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5, Req-8.5, 8.2.1, SRG-OS-000480-GPOS-00227, 6.2.8, SV-230534r627750_rule

Remediation Shell script ⇲

    awk -F: '$3 == 0 && $1 != "root" { print $1 }' /etc/passwd | xargs --no-run-if-empty --max-lines=1 passwd -l

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    - name: Get all /etc/passwd file entries
      getent:
        database: passwd
        split: ':'
      tags:
      - DISA-STIG-RHEL-08-040200
      - NIST-800-171-3.1.1
      - NIST-800-171-3.1.5
      - NIST-800-53-AC-6(5)
      - NIST-800-53-IA-2
      - NIST-800-53-IA-4(b)
      - PCI-DSS-Req-8.5
      - PCI-DSSv4-8.2.1
      - accounts_no_uid_except_zero
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy

    - name: Lock the password of the user accounts other than root with uid 0
      command: passwd -l {{ item.key }}
      loop: '{{ getent_passwd | dict2items | rejectattr(''key'', ''search'', ''root'')
        | list }}'
      when: item.value.1  == '0'
      tags:
      - DISA-STIG-RHEL-08-040200
      - NIST-800-171-3.1.1
      - NIST-800-171-3.1.5
      - NIST-800-53-AC-6(5)
      - NIST-800-53-IA-2
      - NIST-800-53-IA-4(b)
      - PCI-DSS-Req-8.5
      - PCI-DSSv4-8.2.1
      - accounts_no_uid_except_zero
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy

#### Rule Ensure that System Accounts Do Not Run a Shell Upon Login [ref]

Some accounts are not associated with a human user of the system, and exist to perform some administrative functions. Should an attacker be able to log into these accounts, they should not be granted access to a shell.
The login shell for each local account is stored in the last field of each line in `/etc/passwd`. System accounts are those user accounts with a user ID less than `1000`. The user ID is stored in the third field. If any system account other than `root` has a login shell, disable it with the command:

    $ sudo usermod -s /sbin/nologin account

Warning: Do not perform the steps in this section on the root account. Doing so might cause the system to become inaccessible.

Rationale: | Ensuring shells are not given to system accounts upon login makes it more difficult for attackers to make use of system accounts.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_no_shelllogin_for_systemaccounts

Identifiers and References

References: 1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS06.03, CCI-000366, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2, 1491, A.12.4.1, A.12.4.3, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, AC-6, CM-6(a), CM-6(b), CM-6.1(iv), DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, 8.2.2, SRG-OS-000480-GPOS-00227, 5.6.2

Remediation Shell script ⇲

Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | restrict

    readarray -t systemaccounts < <(awk -F: '($3 < 1000 && $3 != root \
      && $7 != "\/sbin\/shutdown" && $7 != "\/sbin\/halt" && $7 != "\/bin\/sync") \
      { print $1 }' /etc/passwd)

    for systemaccount in "${systemaccounts[@]}"; do
        usermod -s /sbin/nologin "$systemaccount"
    done

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | restrict

    - name: Ensure that System Accounts Do Not Run a Shell Upon Login - Get All Local
        Users From /etc/passwd
      ansible.builtin.getent:
        database: passwd
        split: ':'
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - PCI-DSSv4-8.2.2
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - no_shelllogin_for_systemaccounts
      - restrict_strategy

    - name: Ensure that System Accounts Do Not Run a Shell Upon Login - Create local_users
        Variable From getent_passwd Facts
      ansible.builtin.set_fact:
        local_users: '{{ ansible_facts.getent_passwd | dict2items }}'
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - PCI-DSSv4-8.2.2
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - no_shelllogin_for_systemaccounts
      - restrict_strategy

    - name: Ensure that System Accounts Do Not Run a Shell Upon Login -  Disable Login
        Shell for System Accounts
      ansible.builtin.user:
        name: '{{ item.key }}'
        shell: /sbin/nologin
      loop: '{{ local_users }}'
      when:
      - item.key not in ['root']
      - item.value[1]|int < 1000
      - item.value[5] not in ['/sbin/shutdown', '/sbin/halt', '/bin/sync']
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - PCI-DSSv4-8.2.2
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - no_shelllogin_for_systemaccounts
      - restrict_strategy

#### Rule Enable authselect [ref]

Configure user authentication setup to use the `authselect` tool. If authselect profile is selected, the rule will enable the sssd profile.
Warning: If the `sudo authselect select` command returns an error informing that the chosen profile cannot be selected, it is probably because PAM files have already been modified by the administrator. If this is the case, in order to not overwrite the desired changes made by the administrator, the current PAM settings should be investigated before forcing the selection of the chosen authselect profile.

Rationale: | Authselect is a successor to authconfig. It is a tool to select system authentication and identity sources from a list of supported profiles instead of letting the administrator manually build the PAM stack. That way, it avoids potential breakage of configuration, as it ships several tested profiles that are well tested and supported to solve different use-cases.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_enable_authselect
Identifiers and References | References: BP28(R31), CCI-000213, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), AC-3, FIA_UAU.1, FIA_AFL.1, SRG-OS-000480-GPOS-00227, 1.2.3

Remediation Shell script ⇲

    var_authselect_profile='sssd'

    authselect select "$var_authselect_profile"

    if test "$?" -ne 0; then
        if rpm --quiet --verify pam; then
            authselect select --force "$var_authselect_profile"
        else
    	echo "Files in the 'pam' package have been altered, so the authselect configuration won't be forced" >&2
        fi
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | configure

    - name: XCCDF Value var_authselect_profile # promote to variable
      set_fact:
        var_authselect_profile: !!str sssd
      tags:
        - always

    - name: Enable authselect - Select authselect profile
      ansible.builtin.command:
        cmd: authselect select "{{ var_authselect_profile }}"
      register: result_authselect_select
      failed_when: false
      tags:
      - NIST-800-53-AC-3
      - configure_strategy
      - enable_authselect
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: Enable authselect - Verify if PAM has been altered
      ansible.builtin.command:
        cmd: rpm -qV pam
      register: result_altered_authselect
      failed_when: false
      when: result_authselect_select.rc != 0
      tags:
      - NIST-800-53-AC-3
      - configure_strategy
      - enable_authselect
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: Enable authselect - Informative message based on the authselect integrity
        check
      ansible.builtin.assert:
        that:
        - result_altered_authselect is skipped or result_altered_authselect.rc == 0
        fail_msg:
        - Files in the 'pam' package have been altered, so the authselect configuration
          won't be forced.
      tags:
      - NIST-800-53-AC-3
      - configure_strategy
      - enable_authselect
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: Enable authselect - Force authselect profile select
      ansible.builtin.command:
        cmd: authselect select --force "{{ var_authselect_profile }}"
      when:
      - result_authselect_select.rc != 0
      - result_altered_authselect is skipped or result_altered_authselect.rc == 0
      tags:
      - NIST-800-53-AC-3
      - configure_strategy
      - enable_authselect
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

Group System Accounting with auditd Group contains 1 group and 1 rule

[ref] The audit service provides substantial capabilities for recording system activities. By default, the service audits about SELinux AVC denials and certain types of security-relevant events such as system logins, account modifications, and authentication events performed by programs such as sudo. Under its default configuration, `auditd` has modest disk space requirements, and should not noticeably impact system performance.
NOTE: The Linux Audit daemon `auditd` can be configured to use the `augenrules` program to read audit rules files (`*.rules`) located in `/etc/audit/rules.d` location and compile them to create the resulting form of the `/etc/audit/audit.rules` configuration file during the daemon startup (default configuration). Alternatively, the `auditd` daemon can use the `auditctl` utility to read audit rules from the `/etc/audit/audit.rules` configuration file during daemon startup, and load them into the kernel. The expected behavior is configured via the appropriate `ExecStartPost` directive setting in the `/usr/lib/systemd/system/auditd.service` configuration file. To instruct the `auditd` daemon to use the `augenrules` program to read audit rules (default configuration), use the following setting:

    ExecStartPost=-/sbin/augenrules --load

in the `/usr/lib/systemd/system/auditd.service` configuration file. In order to instruct the `auditd` daemon to use the `auditctl` utility to read audit rules, use the following setting:

    ExecStartPost=-/sbin/auditctl -R /etc/audit/audit.rules

in the `/usr/lib/systemd/system/auditd.service` configuration file. Refer to `[Service]` section of the `/usr/lib/systemd/system/auditd.service` configuration file for further details.
Government networks often have substantial auditing requirements and `auditd` can be configured to meet these requirements. Examining some example audit records demonstrates how the Linux audit system satisfies common requirements. The following example from Red Hat Enterprise Linux 7 Documentation available at `https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html-single/selinux_users_and_administrators_guide/index#sect-Security-Enhanced_Linux-Fixing_Problems-Raw_Audit_Messages` shows the substantial amount of information captured in a two typical "raw" audit messages, followed by a breakdown of the most important fields. In this example the message is SELinux-related and reports an AVC denial (and the associated system call) that occurred when the Apache HTTP Server attempted to access the `/var/www/html/file1` file (labeled with the `samba_share_t` type):

    type=AVC msg=audit(1226874073.147:96): avc:  denied  { getattr } for pid=2465 comm="httpd"
    path="/var/www/html/file1" dev=dm-0 ino=284133 scontext=unconfined_u:system_r:httpd_t:s0
    tcontext=unconfined_u:object_r:samba_share_t:s0 tclass=file

    type=SYSCALL msg=audit(1226874073.147:96): arch=40000003 syscall=196 success=no exit=-13
    a0=b98df198 a1=bfec85dc a2=54dff4 a3=2008171 items=0 ppid=2463 pid=2465 auid=502 uid=48
    gid=48 euid=48 suid=48 fsuid=48 egid=48 sgid=48 fsgid=48 tty=(none) ses=6 comm="httpd"
    exe="/usr/sbin/httpd" subj=unconfined_u:system_r:httpd_t:s0 key=(null)

- `msg=audit(1226874073.147:96)`
  - The number in parentheses is the unformatted time stamp (Epoch time) for the event, which can be converted to standard time by using the `date` command.
- `{ getattr }`
  - The item in braces indicates the permission that was denied. `getattr` indicates the source process was trying to read the target file's status information. This occurs before reading files. This action is denied due to the file being accessed having the wrong label. Commonly seen permissions include `getattr`, `read`, and `write`.
- `comm="httpd"`
  - The executable that launched the process. The full path of the executable is found in the `exe=` section of the system call (`SYSCALL`) message, which in this case, is `exe="/usr/sbin/httpd"`.
- `path="/var/www/html/file1"`
  - The path to the object (target) the process attempted to access.
- `scontext="unconfined_u:system_r:httpd_t:s0"`
  - The SELinux context of the process that attempted the denied action. In this case, it is the SELinux context of the Apache HTTP Server, which is running in the `httpd_t` domain.
- `tcontext="unconfined_u:object_r:samba_share_t:s0"`
  - The SELinux context of the object (target) the process attempted to access. In this case, it is the SELinux context of `file1`. Note: the `samba_share_t` type is not accessible to processes running in the `httpd_t` domain.
- From the system call (`SYSCALL`) message, two items are of interest:
  - `success=no`: indicates whether the denial (AVC) was enforced or not. `success=no` indicates the system call was not successful (SELinux denied access). `success=yes` indicates the system call was successful - this can be seen for permissive domains or unconfined domains, such as `initrc_t` and `kernel_t`.
  - `exe="/usr/sbin/httpd"`: the full path to the executable that launched the process, which in this case, is `exe="/usr/sbin/httpd"`.

Group Configure auditd Rules for Comprehensive Auditing Group contains 1 rule

[ref] The `auditd` program can perform comprehensive monitoring of system activity. This section describes recommended configuration settings for comprehensive auditing, but a full description of the auditing system's capabilities is beyond the scope of this guide. The mailing list linux-audit@redhat.com exists to facilitate community discussion of the auditing system.
The audit subsystem supports extensive collection of events, including:

- Tracing of arbitrary system calls (identified by name or number) on entry or exit.
- Filtering by PID, UID, call success, system call argument (with some limitations), etc.
- Monitoring of specific files for modifications to the file's contents or metadata.

Auditing rules at startup are controlled by the file `/etc/audit/audit.rules`. Add rules to it to meet the auditing requirements for your organization. Each line in `/etc/audit/audit.rules` represents a series of arguments that can be passed to `auditctl` and can be individually tested during runtime. See documentation in `/usr/share/doc/audit-VERSION` and in the related man pages for more details.
If copying any example audit rulesets from `/usr/share/doc/audit-VERSION`, be sure to comment out the lines containing `arch=` which are not appropriate for your system's architecture. Then review and understand the following rules, ensuring rules are activated as needed for the appropriate architecture.
After reviewing all the rules, reading the following sections, and editing as needed, the new rules can be activated as follows:

    $ sudo service auditd restart

#### Rule System Audit Logs Must Have Mode 0640 or Less Permissive [ref]

Determine where the audit logs are stored with the following command:

    $ sudo grep -iw log_file /etc/audit/auditd.conf
    log_file = /var/log/audit/audit.log

Configure the audit log to be protected from unauthorized read access by setting the correct permissive mode with the following command:

    $ sudo chmod 0600 audit_log_file

By default, audit_log_file is "/var/log/audit/audit.log".

Rationale: | If users can write to audit logs, audit trails can be modified or destroyed.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_var_log_audit

Identifiers and References

References: 1, 11, 12, 13, 14, 15, 16, 18, 19, 3, 4, 5, 6, 7, 8, 5.4.1.1, APO01.06, APO11.04, APO12.06, BAI03.05, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, DSS06.02, MEA02.01, 3.3.1, CCI-000162, CCI-000163, CCI-000164, CCI-001314, 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.7.3, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 5.2, SR 6.1, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), AU-9(4), DE.AE-3, DE.AE-5, PR.AC-4, PR.DS-5, PR.PT-1, RS.AN-1, RS.AN-4, Req-10.5, 10.3.1, SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029, SRG-OS-000206-GPOS-00084, SRG-APP-000118-CTR-000240, SV-230396r902733_rule

Remediation Shell script ⇲

    # Remediation is applicable only in certain platforms
    if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

    if LC_ALL=C grep -iw ^log_file /etc/audit/auditd.conf; then
        FILE=$(awk -F "=" '/^log_file/ {print $2}' /etc/audit/auditd.conf | tr -d ' ')
    else
        FILE="/var/log/audit/audit.log"
    fi

    chmod 0600 $FILE

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - DISA-STIG-RHEL-08-030070
      - NIST-800-171-3.3.1
      - NIST-800-53-AC-6(1)
      - NIST-800-53-AU-9(4)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5
      - PCI-DSSv4-10.3.1
      - file_permissions_var_log_audit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Get audit log files
      command: grep -iw ^log_file /etc/audit/auditd.conf
      failed_when: false
      register: log_file_exists
      when:
      - '"audit" in ansible_facts.packages'
      - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - CJIS-5.4.1.1
      - DISA-STIG-RHEL-08-030070
      - NIST-800-171-3.3.1
      - NIST-800-53-AC-6(1)
      - NIST-800-53-AU-9(4)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5
      - PCI-DSSv4-10.3.1
      - file_permissions_var_log_audit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Parse log file line
      command: awk -F '=' '/^log_file/ {print $2}' /etc/audit/auditd.conf
      register: log_file_line
      when:
      - '"audit" in ansible_facts.packages'
      - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      - (log_file_exists.stdout | length > 0)
      tags:
      - CJIS-5.4.1.1
      - DISA-STIG-RHEL-08-030070
      - NIST-800-171-3.3.1
      - NIST-800-53-AC-6(1)
      - NIST-800-53-AU-9(4)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5
      - PCI-DSSv4-10.3.1
      - file_permissions_var_log_audit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Set default log_file if not set
      set_fact:
        log_file: /var/log/audit/audit.log
      when:
      - '"audit" in ansible_facts.packages'
      - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      - (log_file_exists is undefined) or (log_file_exists.stdout | length == 0)
      tags:
      - CJIS-5.4.1.1
      - DISA-STIG-RHEL-08-030070
      - NIST-800-171-3.3.1
      - NIST-800-53-AC-6(1)
      - NIST-800-53-AU-9(4)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5
      - PCI-DSSv4-10.3.1
      - file_permissions_var_log_audit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Set log_file from log_file_line if not set already
      set_fact:
        log_file: '{{ log_file_line.stdout | trim }}'
      when:
      - '"audit" in ansible_facts.packages'
      - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      - (log_file_line.stdout is defined) and (log_file_line.stdout | length > 0)
      tags:
      - CJIS-5.4.1.1
      - DISA-STIG-RHEL-08-030070
      - NIST-800-171-3.3.1
      - NIST-800-53-AC-6(1)
      - NIST-800-53-AU-9(4)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5
      - PCI-DSSv4-10.3.1
      - file_permissions_var_log_audit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Apply mode to log file
      file:
        path: '{{ log_file }}'
        mode: 384
      failed_when: false
      when:
      - '"audit" in ansible_facts.packages'
      - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - CJIS-5.4.1.1
      - DISA-STIG-RHEL-08-030070
      - NIST-800-171-3.3.1
      - NIST-800-53-AC-6(1)
      - NIST-800-53-AU-9(4)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5
      - PCI-DSSv4-10.3.1
      - file_permissions_var_log_audit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

Group GRUB2 bootloader configuration Group contains 1 group and 4 rules

[ref] During the boot process, the boot loader is responsible for starting the execution of the kernel and passing options to it. The boot loader allows for the selection of different kernels - possibly on different partitions or media. The default Red Hat Enterprise Linux 8 boot loader for x86 systems is called GRUB2. Options it can pass to the kernel include single-user mode, which provides root access without any authentication, and the ability to disable SELinux. To prevent local users from modifying the boot parameters and endangering security, protect the boot loader configuration with a password and ensure its configuration file's permissions are set properly.

Group Non-UEFI GRUB2 bootloader configuration Group contains 4 rules
[ref] Non-UEFI GRUB2 bootloader configuration

#### Rule Verify /boot/grub2/grub.cfg Group Ownership [ref]

The file `/boot/grub2/grub.cfg` should be group-owned by the `root` group to prevent destruction or modification of the file. To properly set the group owner of `/boot/grub2/grub.cfg`, run the command:

    $ sudo chgrp root /boot/grub2/grub.cfg

Rationale: | The `root` group is a highly-privileged group. Furthermore, the group-owner of this file should not have any access privileges anyway.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_grub2_cfg

Identifiers and References

References: 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.4.5, CCI-000225, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-7.1, 2.2.6, SRG-OS-000480-GPOS-00227, 1.4.2

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    # Remediation is applicable only in certain platforms
    if [ ! -d /sys/firmware/efi ] && rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

    chgrp 0 /boot/grub2/grub.cfg

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.5.2.2
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-7.1
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_grub2_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /boot/grub2/grub.cfg
      stat:
        path: /boot/grub2/grub.cfg
      register: file_exists
      when:
      - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
      - '"grub2-common" in ansible_facts.packages'
      - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - CJIS-5.5.2.2
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-7.1
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_grub2_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner 0 on /boot/grub2/grub.cfg
      file:
        path: /boot/grub2/grub.cfg
        group: '0'
      when:
      - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
      - '"grub2-common" in ansible_facts.packages'
      - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-7.1
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_grub2_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

#### Rule Verify /boot/grub2/grub.cfg User Ownership [ref]

The file `/boot/grub2/grub.cfg` should be owned by the `root` user to prevent destruction or modification of the file. To properly set the owner of `/boot/grub2/grub.cfg`, run the command:

    $ sudo chown root /boot/grub2/grub.cfg

Rationale: | Only root should be able to modify important boot parameters.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_grub2_cfg

Identifiers and References

References: 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.4.5, CCI-000225, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-7.1, 2.2.6, SRG-OS-000480-GPOS-00227, 1.4.2

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    # Remediation is applicable only in certain platforms
    if [ ! -d /sys/firmware/efi ] && rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

    chown 0 /boot/grub2/grub.cfg

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.5.2.2
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-7.1
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_grub2_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /boot/grub2/grub.cfg
      stat:
        path: /boot/grub2/grub.cfg
      register: file_exists
      when:
      - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
      - '"grub2-common" in ansible_facts.packages'
      - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - CJIS-5.5.2.2
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-7.1
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_grub2_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner 0 on /boot/grub2/grub.cfg
      file:
        path: /boot/grub2/grub.cfg
        owner: '0'
      when:
      - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
      - '"grub2-common" in ansible_facts.packages'
      - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-7.1
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_grub2_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

#### Rule Verify /boot/grub2/grub.cfg Permissions [ref]

File permissions for `/boot/grub2/grub.cfg` should be set to 600. To properly set the permissions of `/boot/grub2/grub.cfg`, run the command:

    $ sudo chmod 600 /boot/grub2/grub.cfg

Rationale: | Proper permissions ensure that only the root user can modify important boot parameters.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_grub2_cfg

Identifiers and References

References: 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.4.5, CCI-000225, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, 2.2.6, 1.4.2

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    # Remediation is applicable only in certain platforms
    if [ ! -d /sys/firmware/efi ] && rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

    chmod u-xs,g-xwrs,o-xwrt /boot/grub2/grub.cfg

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_grub2_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /boot/grub2/grub.cfg
      stat:
        path: /boot/grub2/grub.cfg
      register: file_exists
      when:
      - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
      - '"grub2-common" in ansible_facts.packages'
      - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_grub2_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-xs,g-xwrs,o-xwrt on /boot/grub2/grub.cfg
      file:
        path: /boot/grub2/grub.cfg
        mode: u-xs,g-xwrs,o-xwrt
      when:
      - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
      - '"grub2-common" in ansible_facts.packages'
      - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_grub2_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

#### Rule Set Boot Loader Password in grub2 [ref]

The grub2 boot loader should have a superuser account and password protection enabled to protect boot-time settings.
Since plaintext passwords are a security risk, generate a hash for the password by running the following command:

    # grub2-setpassword

When prompted, enter the password that was selected.
Warning: To prevent hard-coded passwords, automatic remediation of this control is not available. Remediation must be automated as a component of machine provisioning, or followed manually as outlined above. Also, do NOT manually add the superuser account and password to the `grub.cfg` file as the grub2-mkconfig command overwrites this file.

Rationale: | Password protection on the boot loader configuration ensures users with physical access cannot trivially alter important bootloader settings. These include which kernel to use, and whether to enter single-user mode.
Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_grub2_password

Identifiers and References

References: BP28(R17), 1, 11, 12, 14, 15, 16, 18, 3, 5, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.06, DSS06.10, 3.4.5, CCI-000213, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, A.18.1.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CM-6(a), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.PT-3, FIA_UAU.1, SRG-OS-000080-GPOS-00048, 1.4.1, SV-230235r743925_rule

Group Network Configuration and Firewalls Group contains 4 groups and 4 rules

[ref] Most systems must be connected to a network of some sort, and this brings with it the substantial risk of network attack. This section discusses the security impact of decisions about networking which must be made when configuring a system.
This section also discusses firewalls, network access controls, and other network security frameworks, which allow system-level rules to be written that can limit an attackers' ability to connect to your system. These rules can specify that network traffic should be allowed or denied from certain IP addresses, hosts, and networks. The rules can also specify which of the system's network services are available to particular hosts or networks.

Group firewalld Group contains 2 groups and 2 rules

[ref] The dynamic firewall daemon `firewalld` provides a dynamically managed firewall with support for network “zones” to assign a level of trust to a network and its associated connections and interfaces. It has support for IPv4 and IPv6 firewall settings. It supports Ethernet bridges and has a separation of runtime and permanent configuration options. It also has an interface for services or applications to add firewall rules directly.
A graphical configuration tool, `firewall-config`, is used to configure `firewalld`, which in turn uses `iptables` tool to communicate with `Netfilter` in the kernel which implements packet filtering.
The firewall service provided by `firewalld` is dynamic rather than static because changes to the configuration can be made at anytime and are immediately implemented. There is no need to save or apply the changes. No unintended disruption of existing network connections occurs as no part of the firewall has to be reloaded.

Group Inspect and Activate Default firewalld Rules Group contains 1 rule

[ref] Firewalls can be used to separate networks into different zones based on the level of trust the user has decided to place on the devices and traffic within that network. `NetworkManager` informs firewalld to which zone an interface belongs. An interface's assigned zone can be changed by `NetworkManager` or via the `firewall-config` tool.
The zone settings in `/etc/firewalld/` are a range of preset settings which can be quickly applied to a network interface. These are the zones provided by firewalld sorted according to the default trust level of the zones from untrusted to trusted:

- `drop`

  Any incoming network packets are dropped, there is no reply. Only outgoing network connections are possible.

- `block`

  Any incoming network connections are rejected with an `icmp-host-prohibited` message for IPv4 and `icmp6-adm-prohibited` for IPv6. Only network connections initiated from within the system are possible.

- `public`

  For use in public areas. You do not trust the other computers on the network to not harm your computer. Only selected incoming connections are accepted.

- `external`

  For use on external networks with masquerading enabled especially for routers. You do not trust the other computers on the network to not harm your computer. Only selected incoming connections are accepted.

- `dmz`

  For computers in your demilitarized zone that are publicly-accessible with limited access to your internal network. Only selected incoming connections are accepted.

- `work`

  For use in work areas. You mostly trust the other computers on networks to not harm your computer. Only selected incoming connections are accepted.

- `home`

  For use in home areas. You mostly trust the other computers on networks to not harm your computer. Only selected incoming connections are accepted.

- `internal`

  For use on internal networks. You mostly trust the other computers on the networks to not harm your computer. Only selected incoming connections are accepted.

- `trusted`

  All network connections are accepted.

It is possible to designate one of these zones to be the default zone. When interface connections are added to `NetworkManager`, they are assigned to the default zone. On installation, the default zone in firewalld is set to be the public zone.
To find out all the settings of a zone, for example the `public zone,` enter the following command as root:

    # firewall-cmd --zone=public --list-all

Example output of this command might look like the following:

    # firewall-cmd --zone=public --list-all
    public
      interfaces:
      services: mdns dhcpv6-client ssh
      ports:
      forward-ports:
      icmp-blocks: source-quench

To view the network zones currently active, enter the following command as root:

    # firewall-cmd --get-service

The following listing displays the result of this command on common Red Hat Enterprise Linux 8 system:

    # firewall-cmd --get-service
    amanda-client bacula bacula-client dhcp dhcpv6 dhcpv6-client dns ftp
    high-availability http https imaps ipp ipp-client ipsec kerberos kpasswd
    ldap ldaps libvirt libvirt-tls mdns mountd ms-wbt mysql nfs ntp openvpn
    pmcd pmproxy pmwebapi pmwebapis pop3s postgresql proxy-dhcp radius rpc-bind
    samba samba-client smtp ssh telnet tftp tftp-client transmission-client
    vnc-server wbem-https

Finally to view the network zones that will be active after the next firewalld service reload, enter the following command as root:

    # firewall-cmd --get-service --permanent

#### Rule Verify firewalld Enabled [ref]

The `firewalld` service can be enabled with the following command:

    $ sudo systemctl enable firewalld.service

Rationale: | Access control methods provide the ability to enhance system security posture by restricting services and known good IP addresses and address ranges. This prevents connections from unknown hosts and protocols.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_service_firewalld_enabled

Identifiers and References

References: 11, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, 3.1.3, 3.4.7, CCI-000366, CCI-000382, CCI-002314, 4.3.4.3.2, 4.3.4.3.3, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, CIP-003-8 R4, CIP-003-8 R5, CIP-004-6 R3, AC-4, CM-7(b), CA-3(5), SC-7(21), CM-6(a), PR.IP-1, FMT_SMF_EXT.1, 1.2.1, SRG-OS-000096-GPOS-00050, SRG-OS-000297-GPOS-00115, SRG-OS-000480-GPOS-00227, SRG-OS-000480-GPOS-00231, SRG-OS-000480-GPOS-00232, 3.4.1.4, SV-244544r854073_rule

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable

    # Remediation is applicable only in certain platforms
    if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && { rpm --quiet -q firewalld; }; then

    SYSTEMCTL_EXEC='/usr/bin/systemctl'
    "$SYSTEMCTL_EXEC" unmask 'firewalld.service'
    "$SYSTEMCTL_EXEC" start 'firewalld.service'
    "$SYSTEMCTL_EXEC" enable 'firewalld.service'

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable

    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - DISA-STIG-RHEL-08-040101
      - NIST-800-171-3.1.3
      - NIST-800-171-3.4.7
      - NIST-800-53-AC-4
      - NIST-800-53-CA-3(5)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(21)
      - PCI-DSSv4-1.2.1
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - service_firewalld_enabled

    - name: Enable service firewalld
      block:

      - name: Gather the package facts
        package_facts:
          manager: auto

      - name: Enable service firewalld
        systemd:
          name: firewalld
          enabled: 'yes'
          state: started
          masked: 'no'
        when:
        - '"firewalld" in ansible_facts.packages'
      when:
      - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      - '"firewalld" in ansible_facts.packages'
      tags:
      - DISA-STIG-RHEL-08-040101
      - NIST-800-171-3.1.3
      - NIST-800-171-3.4.7
      - NIST-800-53-AC-4
      - NIST-800-53-CA-3(5)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(21)
      - PCI-DSSv4-1.2.1
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - service_firewalld_enabled

Remediation OSBuild Blueprint snippet ⇲

    [customizations.services]
    enabled = ["firewalld"]

Remediation Puppet snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable

    include enable_firewalld

    class enable_firewalld {
      service {'firewalld':
        enable => true,
        ensure => 'running',
      }
    }

Group Strengthen the Default Ruleset Group contains 1 rule

[ref] The default rules can be strengthened. The system scripts that activate the firewall rules expect them to be defined in configuration files under the `/etc/firewalld/services` and `/etc/firewalld/zones` directories.
The following recommendations describe how to strengthen the default ruleset configuration file. An alternative to editing this configuration file is to create a shell script that makes calls to the `firewall-cmd` program to load in rules under the `/etc/firewalld/services` and `/etc/firewalld/zones` directories.
Instructions apply to both unless otherwise noted. Language and address conventions for regular firewalld rules are used throughout this section.
Warning: The program `firewall-config` allows additional services to penetrate the default firewall rules and automatically adjusts the `firewalld` ruleset(s).

#### Rule Set Default firewalld Zone for Incoming Packets [ref]

To set the default zone to `drop` for the built-in default zone which processes incoming IPv4 and IPv6 packets, modify the following line in `/etc/firewalld/firewalld.conf` to be:

    DefaultZone=drop

Warning: To prevent denying any access to the system, automatic remediation of this control is not available. Remediation must be automated as a component of machine provisioning, or followed manually as outlined above.

Rationale: | In `firewalld` the default zone is applied only after all the applicable rules in the table are examined for a match. Setting the default zone to `drop` implements proper design for a firewall, i.e. any packets which are not explicitly permitted should not be accepted.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_set_firewalld_default_zone

Identifiers and References

References: 11, 14, 3, 9, 5.10.1, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.1.3, 3.4.7, 3.13.6, CCI-000366, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, 1416, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CA-3(5), CM-7(b), SC-7(23), CM-6(a), PR.IP-1, PR.PT-3, FMT_MOF_EXT.1, Req-1.4, 1.3.1, 1.5.1, SRG-OS-000480-GPOS-00227, 3.4.1.5, SV-230504r854047_rule

Group Uncommon Network Protocols Group contains 2 rules

[ref] The system includes support for several network protocols which are not commonly used. Although security vulnerabilities in kernel networking code are not frequently discovered, the consequences can be dramatic. Ensuring uncommon network protocols are disabled reduces the system's risk to attacks targeted at its implementation of those protocols.
Warning: Although these protocols are not commonly used, avoid disruption in your network environment by ensuring they are not needed prior to disabling them.

#### Rule Disable DCCP Support [ref]

The Datagram Congestion Control Protocol (DCCP) is a relatively new transport layer protocol, designed to support streaming media and telephony. To configure the system to prevent the `dccp` kernel module from being loaded, add the following line to the file `/etc/modprobe.d/dccp.conf`:

    install dccp /bin/true

To configure the system to prevent the `dccp` from being used, add the following line to file `/etc/modprobe.d/dccp.conf`:

    blacklist dccp

Rationale: | Disabling DCCP protects the system against exploitation of any flaws in its implementation.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_kernel_module_dccp_disabled

Identifiers and References

References: 11, 14, 3, 9, 5.10.1, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.4.6, CCI-001958, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, Req-1.4.2, 1.4.2, SRG-OS-000096-GPOS-00050, SRG-OS-000378-GPOS-00163, 3.1.3

Remediation Shell script ⇲

Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable

    # Remediation is applicable only in certain platforms
    if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

    if LC_ALL=C grep -q -m 1 "^install dccp" /etc/modprobe.d/dccp.conf ; then

    	sed -i 's#^install dccp.*#install dccp /bin/true#g' /etc/modprobe.d/dccp.conf
    else
    	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/dccp.conf
    	echo "install dccp /bin/true" >> /etc/modprobe.d/dccp.conf
    fi

    if ! LC_ALL=C grep -q -m 1 "^blacklist dccp$" /etc/modprobe.d/dccp.conf ; then
    	echo "blacklist dccp" >> /etc/modprobe.d/dccp.conf
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable

    - name: Ensure kernel module 'dccp' is disabled
      lineinfile:
        create: true
        dest: /etc/modprobe.d/dccp.conf
        regexp: install\s+dccp
        line: install dccp /bin/true
      when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - CJIS-5.10.1
      - NIST-800-171-3.4.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-1.4.2
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - kernel_module_dccp_disabled
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required

    - name: Ensure kernel module 'dccp' is blacklisted
      lineinfile:
        create: true
        dest: /etc/modprobe.d/dccp.conf
        regexp: ^blacklist dccp$
        line: blacklist dccp
      when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - CJIS-5.10.1
      - NIST-800-171-3.4.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-1.4.2
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - kernel_module_dccp_disabled
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required

Remediation Kubernetes snippet ⇲

Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable

    ---
    apiVersion: machineconfiguration.openshift.io/v1
    kind: MachineConfig
    spec:
      config:
        ignition:
          version: 3.1.0
        storage:
          files:
          - contents:
              source: data:,install%20dccp%20/bin/true%0Ablacklist%20dccp%0A
            mode: 0644
            path: /etc/modprobe.d/dccp.conf
            overwrite: true

#### Rule Disable SCTP Support [ref]

The Stream Control Transmission Protocol (SCTP) is a transport layer protocol, designed to support the idea of message-oriented communication, with several streams of messages within one connection. To configure the system to prevent the `sctp` kernel module from being loaded, add the following line to the file `/etc/modprobe.d/sctp.conf`:

    install sctp /bin/true

To configure the system to prevent the `sctp` from being used, add the following line to file `/etc/modprobe.d/sctp.conf`:

    blacklist sctp

Rationale: | Disabling SCTP protects the system against exploitation of any flaws in its implementation.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_kernel_module_sctp_disabled

Identifiers and References

References: 11, 14, 3, 9, 5.10.1, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.4.6, CCI-000381, CCI-000366, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, Req-1.4.2, 1.4.2, SRG-OS-000095-GPOS-00049, SRG-OS-000480-GPOS-00227, 3.1.2, SV-230496r792917_rule

Remediation Shell script ⇲

Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable

    # Remediation is applicable only in certain platforms
    if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

    if LC_ALL=C grep -q -m 1 "^install sctp" /etc/modprobe.d/sctp.conf ; then

    	sed -i 's#^install sctp.*#install sctp /bin/true#g' /etc/modprobe.d/sctp.conf
    else
    	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/sctp.conf
    	echo "install sctp /bin/true" >> /etc/modprobe.d/sctp.conf
    fi

    if ! LC_ALL=C grep -q -m 1 "^blacklist sctp$" /etc/modprobe.d/sctp.conf ; then
    	echo "blacklist sctp" >> /etc/modprobe.d/sctp.conf
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable

    - name: Ensure kernel module 'sctp' is disabled
      lineinfile:
        create: true
        dest: /etc/modprobe.d/sctp.conf
        regexp: install\s+sctp
        line: install sctp /bin/true
      when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - CJIS-5.10.1
      - DISA-STIG-RHEL-08-040023
      - NIST-800-171-3.4.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-1.4.2
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - kernel_module_sctp_disabled
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required

    - name: Ensure kernel module 'sctp' is blacklisted
      lineinfile:
        create: true
        dest: /etc/modprobe.d/sctp.conf
        regexp: ^blacklist sctp$
        line: blacklist sctp
      when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - CJIS-5.10.1
      - DISA-STIG-RHEL-08-040023
      - NIST-800-171-3.4.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-1.4.2
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - kernel_module_sctp_disabled
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required

Remediation Kubernetes snippet ⇲

Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable

    ---
    apiVersion: machineconfiguration.openshift.io/v1
    kind: MachineConfig
    spec:
      config:
        ignition:
          version: 3.1.0
        storage:
          files:
          - contents:
              source: data:,install%20sctp%20/bin/true%0Ablacklist%20sctp%0A
            mode: 0644
            path: /etc/modprobe.d/sctp.conf
            overwrite: true

Group File Permissions and Masks Group contains 3 groups and 16 rules

[ref] Traditional Unix security relies heavily on file and directory permissions to prevent unauthorized users from reading or modifying files to which they should not have access.
Several of the commands in this section search filesystems for files or directories with certain characteristics, and are intended to be run on every local partition on a given system. When the variable PART appears in one of the commands below, it means that the command is intended to be run repeatedly, with the name of each local partition substituted for PART in turn.
The following command prints a list of all xfs partitions on the local system, which is the default filesystem for Red Hat Enterprise Linux 8 installations:

    $ mount -t xfs | awk '{print $3}'

For any systems that use a different local filesystem type, modify this command as appropriate.

Group Verify Permissions on Important Files and Directories Group contains 2 groups and 16 rules
[ref] Permissions for many files on a system must be set restrictively to ensure sensitive information is properly protected. This section discusses important permission restrictions which can be verified to ensure that no harmful discrepancies have arisen.
Group Verify Permissions on Files with Local Account Information and Credentials Group contains 12 rules
[ref] The default restrictive permissions for files which act as important security databases such as `passwd`, `shadow`, `group`, and `gshadow` files must be maintained. Many utilities need read access to the `passwd` file in order to function properly, but read access to the `shadow` file allows malicious attacks against system passwords, and should never be enabled.

#### Rule Verify Group Who Owns group File [ref]

To properly set the group owner of `/etc/group`, run the command:

    $ sudo chgrp root /etc/group

Rationale: | The `/etc/group` file contains information regarding groups that are configured on the system. Protection of this file is important for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_etc_group

Identifiers and References

References: 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, 2.2.6, SRG-OS-000480-GPOS-00227, 6.1.5

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    chgrp 0 /etc/group

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    - name: Test for existence /etc/group
      stat:
        path: /etc/group
      register: file_exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_etc_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner 0 on /etc/group
      file:
        path: /etc/group
        group: '0'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_etc_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

#### Rule Verify Group Who Owns gshadow File [ref]

To properly set the group owner of `/etc/gshadow`, run the command:

    $ sudo chgrp root /etc/gshadow

Rationale: | The `/etc/gshadow` file contains group password hashes. Protection of this file is critical for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_etc_gshadow

Identifiers and References

References: 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 6.1.6

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    chgrp 0 /etc/gshadow

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    - name: Test for existence /etc/gshadow
      stat:
        path: /etc/gshadow
      register: file_exists
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_groupowner_etc_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner 0 on /etc/gshadow
      file:
        path: /etc/gshadow
        group: '0'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_groupowner_etc_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

#### Rule Verify Group Who Owns passwd File [ref]

To properly set the group owner of `/etc/passwd`, run the command:

    $ sudo chgrp root /etc/passwd

Rationale: | The `/etc/passwd` file contains information about the users that are configured on the system. Protection of this file is critical for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_etc_passwd

Identifiers and References

References: 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, 2.2.6, SRG-OS-000480-GPOS-00227, 6.1.3

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    chgrp 0 /etc/passwd

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    - name: Test for existence /etc/passwd
      stat:
        path: /etc/passwd
      register: file_exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_etc_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner 0 on /etc/passwd
      file:
        path: /etc/passwd
        group: '0'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_etc_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

#### Rule Verify Group Who Owns shadow File [ref]

To properly set the group owner of `/etc/shadow`, run the command:

    $ sudo chgrp root /etc/shadow

Rationale: | The `/etc/shadow` file stores password hashes. Protection of this file is critical for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_etc_shadow

Identifiers and References

References: 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, 2.2.6, SRG-OS-000480-GPOS-00227, 6.1.4

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    chgrp 0 /etc/shadow

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    - name: Test for existence /etc/shadow
      stat:
        path: /etc/shadow
      register: file_exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_etc_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner 0 on /etc/shadow
      file:
        path: /etc/shadow
        group: '0'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_etc_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

#### Rule Verify User Who Owns group File [ref]

To properly set the owner of `/etc/group`, run the command:

    $ sudo chown root /etc/group

Rationale: | The `/etc/group` file contains information regarding groups that are configured on the system. Protection of this file is important for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_etc_group

Identifiers and References

References: 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, 2.2.6, SRG-OS-000480-GPOS-00227, 6.1.5

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    chown 0 /etc/group

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    - name: Test for existence /etc/group
      stat:
        path: /etc/group
      register: file_exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_etc_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner 0 on /etc/group
      file:
        path: /etc/group
        owner: '0'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_etc_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

#### Rule Verify User Who Owns gshadow File [ref]

To properly set the owner of `/etc/gshadow`, run the command:

    $ sudo chown root /etc/gshadow

Rationale: | The `/etc/gshadow` file contains group password hashes. Protection of this file is critical for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_etc_gshadow

Identifiers and References

References: BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 6.1.6

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    chown 0 /etc/gshadow

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    - name: Test for existence /etc/gshadow
      stat:
        path: /etc/gshadow
      register: file_exists
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_owner_etc_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner 0 on /etc/gshadow
      file:
        path: /etc/gshadow
        owner: '0'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_owner_etc_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

#### Rule Verify User Who Owns passwd File [ref]

To properly set the owner of `/etc/passwd`, run the command:

    $ sudo chown root /etc/passwd

Rationale: | The `/etc/passwd` file contains information about the users that are configured on the system. Protection of this file is critical for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_etc_passwd

Identifiers and References

References: 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, 2.2.6, SRG-OS-000480-GPOS-00227, 6.1.3

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    chown 0 /etc/passwd

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    - name: Test for existence /etc/passwd
      stat:
        path: /etc/passwd
      register: file_exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_etc_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner 0 on /etc/passwd
      file:
        path: /etc/passwd
        owner: '0'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_etc_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

#### Rule Verify User Who Owns shadow File [ref]

To properly set the owner of `/etc/shadow`, run the command:

    $ sudo chown root /etc/shadow

Rationale: | The `/etc/shadow` file contains the list of local system accounts and stores password hashes. Protection of this file is critical for system security. Failure to give ownership of this file to root provides the designated owner with access to sensitive information which could weaken the system security posture.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_etc_shadow

Identifiers and References

References: BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, 2.2.6, SRG-OS-000480-GPOS-00227, 6.1.4

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    chown 0 /etc/shadow

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    - name: Test for existence /etc/shadow
      stat:
        path: /etc/shadow
      register: file_exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_etc_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner 0 on /etc/shadow
      file:
        path: /etc/shadow
        owner: '0'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_etc_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

#### Rule Verify Permissions on group File [ref]

To properly set the permissions of `/etc/passwd`, run the command:

    $ sudo chmod 0644 /etc/passwd

Rationale: | The `/etc/group` file contains information regarding groups that are configured on the system. Protection of this file is important for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_etc_group

Identifiers and References

References: BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, 2.2.6, SRG-OS-000480-GPOS-00227, 6.1.5

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    chmod u-xs,g-xws,o-xwt /etc/group

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    - name: Test for existence /etc/group
      stat:
        path: /etc/group
      register: file_exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_etc_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-xs,g-xws,o-xwt on /etc/group
      file:
        path: /etc/group
        mode: u-xs,g-xws,o-xwt
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_etc_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

#### Rule Verify Permissions on gshadow File [ref]

To properly set the permissions of `/etc/gshadow`, run the command:

    $ sudo chmod 0000 /etc/gshadow

Rationale: | The `/etc/gshadow` file contains group password hashes. Protection of this file is critical for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_etc_gshadow

Identifiers and References

References: BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 6.1.6

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    chmod u-xwrs,g-xwrs,o-xwrt /etc/gshadow

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    - name: Test for existence /etc/gshadow
      stat:
        path: /etc/gshadow
      register: file_exists
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_permissions_etc_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-xwrs,g-xwrs,o-xwrt on /etc/gshadow
      file:
        path: /etc/gshadow
        mode: u-xwrs,g-xwrs,o-xwrt
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_permissions_etc_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

#### Rule Verify Permissions on passwd File [ref]

To properly set the permissions of `/etc/passwd`, run the command:

    $ sudo chmod 0644 /etc/passwd

Rationale: | If the `/etc/passwd` file is writable by a group-owner or the world the risk of its compromise is increased. The file contains the list of accounts on the system and associated information, and protection of this file is critical for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_etc_passwd

Identifiers and References

References: BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, 2.2.6, SRG-OS-000480-GPOS-00227, 6.1.3

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    chmod u-xs,g-xws,o-xwt /etc/passwd

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    - name: Test for existence /etc/passwd
      stat:
        path: /etc/passwd
      register: file_exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_etc_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-xs,g-xws,o-xwt on /etc/passwd
      file:
        path: /etc/passwd
        mode: u-xs,g-xws,o-xwt
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_etc_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

#### Rule Verify Permissions on shadow File [ref]

To properly set the permissions of `/etc/shadow`, run the command:

    $ sudo chmod 0000 /etc/shadow

Rationale: | The `/etc/shadow` file contains the list of local system accounts and stores password hashes. Protection of this file is critical for system security. Failure to give ownership of this file to root provides the designated owner with access to sensitive information which could weaken the system security posture.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_etc_shadow

Identifiers and References

References: BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, 2.2.6, SRG-OS-000480-GPOS-00227, 6.1.4

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    chmod u-xwrs,g-xwrs,o-xwrt /etc/shadow

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    - name: Test for existence /etc/shadow
      stat:
        path: /etc/shadow
      register: file_exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_etc_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-xwrs,g-xwrs,o-xwrt on /etc/shadow
      file:
        path: /etc/shadow
        mode: u-xwrs,g-xwrs,o-xwrt
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_etc_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

Group Verify File Permissions Within Some Important Directories Group contains 4 rules
[ref] Some directories contain files whose confidentiality or integrity is notably important and may also be susceptible to misconfiguration over time, particularly if unpackaged software is installed. As such, an argument exists to verify that files' permissions within these directories remain configured correctly and restrictively.

#### Rule Verify that System Executables Have Root Ownership [ref]

System executables are stored in the following directories by default:

    /bin
    /sbin
    /usr/bin
    /usr/libexec
    /usr/local/bin
    /usr/local/sbin
    /usr/sbin

All files in these directories should be owned by the `root` user. If any file FILE in these directories is found to be owned by a user other than root, correct its ownership with the following command:

    $ sudo chown root FILE

Rationale: | System binaries are executed by privileged users as well as system services, and restrictive permissions are necessary to ensure that their execution of these programs cannot be co-opted.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_ownership_binary_dirs

Identifiers and References

References: 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-001499, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-5(6), CM-5(6).1, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000259-GPOS-00100, SV-230258r627750_rule

Remediation Shell script ⇲

    find /bin/ \
    /usr/bin/ \
    /usr/local/bin/ \
    /sbin/ \
    /usr/sbin/ \
    /usr/local/sbin/ \
    /usr/libexec \
    \! -user root -execdir chown root {} \;

Remediation Ansible snippet ⇲

Complexity: | medium
Disruption: | medium
Reboot: | false
Strategy: | restrict

    - name: Read list of system executables without root ownership
      command: find /bin/ /usr/bin/ /usr/local/bin/ /sbin/ /usr/sbin/ /usr/local/sbin/
        /usr/libexec \! -user root
      register: no_root_system_executables
      changed_when: false
      failed_when: false
      check_mode: false
      tags:
      - DISA-STIG-RHEL-08-010310
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-5(6)
      - NIST-800-53-CM-5(6).1
      - NIST-800-53-CM-6(a)
      - file_ownership_binary_dirs
      - medium_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Set ownership to root of system executables
      file:
        path: '{{ item }}'
        owner: root
      with_items: '{{ no_root_system_executables.stdout_lines }}'
      when: no_root_system_executables.stdout_lines | length > 0
      tags:
      - DISA-STIG-RHEL-08-010310
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-5(6)
      - NIST-800-53-CM-5(6).1
      - NIST-800-53-CM-6(a)
      - file_ownership_binary_dirs
      - medium_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

#### Rule Verify that Shared Library Files Have Root Ownership [ref]

System-wide shared library files, which are linked to executables during process load time or run time, are stored in the following directories by default:

    /lib
    /lib64
    /usr/lib
    /usr/lib64

Kernel modules, which can be added to the kernel during runtime, are also stored in `/lib/modules`. All files in these directories should be owned by the `root` user. If the directory, or any file in these directories, is found to be owned by a user other than root correct its ownership with the following command:

    $ sudo chown root FILE

Rationale: | Files from shared library directories are loaded into the address space of processes (including privileged ones) or of the kernel itself at runtime. Proper ownership is necessary to protect the integrity of the system.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_ownership_library_dirs

Identifiers and References

References: 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-001499, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-5(6), CM-5(6).1, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000259-GPOS-00100, SV-230261r627750_rule

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    find /lib/  -type f ! -uid 0 -regex '^.*$' -exec chown 0 {} \;

    find /lib64/  -type f ! -uid 0 -regex '^.*$' -exec chown 0 {} \;

    find /usr/lib/  -type f ! -uid 0 -regex '^.*$' -exec chown 0 {} \;

    find /usr/lib64/  -type f ! -uid 0 -regex '^.*$' -exec chown 0 {} \;

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    - name: Find /lib/ file(s) matching ^.*$ recursively
      command: find -H /lib/  -type f ! -uid 0 -regex "^.*$"
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      tags:
      - DISA-STIG-RHEL-08-010340
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-5(6)
      - NIST-800-53-CM-5(6).1
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_ownership_library_dirs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /lib/ file(s) matching ^.*$
      file:
        path: '{{ item }}'
        owner: '0'
        state: file
      with_items:
      - '{{ files_found.stdout_lines }}'
      tags:
      - DISA-STIG-RHEL-08-010340
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-5(6)
      - NIST-800-53-CM-5(6).1
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_ownership_library_dirs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find /lib64/ file(s) matching ^.*$ recursively
      command: find -H /lib64/  -type f ! -uid 0 -regex "^.*$"
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      tags:
      - DISA-STIG-RHEL-08-010340
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-5(6)
      - NIST-800-53-CM-5(6).1
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_ownership_library_dirs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /lib64/ file(s) matching ^.*$
      file:
        path: '{{ item }}'
        owner: '0'
        state: file
      with_items:
      - '{{ files_found.stdout_lines }}'
      tags:
      - DISA-STIG-RHEL-08-010340
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-5(6)
      - NIST-800-53-CM-5(6).1
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_ownership_library_dirs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find /usr/lib/ file(s) matching ^.*$ recursively
      command: find -H /usr/lib/  -type f ! -uid 0 -regex "^.*$"
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      tags:
      - DISA-STIG-RHEL-08-010340
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-5(6)
      - NIST-800-53-CM-5(6).1
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_ownership_library_dirs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /usr/lib/ file(s) matching ^.*$
      file:
        path: '{{ item }}'
        owner: '0'
        state: file
      with_items:
      - '{{ files_found.stdout_lines }}'
      tags:
      - DISA-STIG-RHEL-08-010340
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-5(6)
      - NIST-800-53-CM-5(6).1
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_ownership_library_dirs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find /usr/lib64/ file(s) matching ^.*$ recursively
      command: find -H /usr/lib64/  -type f ! -uid 0 -regex "^.*$"
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      tags:
      - DISA-STIG-RHEL-08-010340
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-5(6)
      - NIST-800-53-CM-5(6).1
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_ownership_library_dirs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /usr/lib64/ file(s) matching ^.*$
      file:
        path: '{{ item }}'
        owner: '0'
        state: file
      with_items:
      - '{{ files_found.stdout_lines }}'
      tags:
      - DISA-STIG-RHEL-08-010340
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-5(6)
      - NIST-800-53-CM-5(6).1
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_ownership_library_dirs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

#### Rule Verify that System Executables Have Restrictive Permissions [ref]

System executables are stored in the following directories by default:

    /bin
    /sbin
    /usr/bin
    /usr/libexec
    /usr/local/bin
    /usr/local/sbin
    /usr/sbin

All files in these directories should not be group-writable or world-writable. If any file FILE in these directories is found to be group-writable or world-writable, correct its permission with the following command:

    $ sudo chmod go-w FILE

Rationale: | System binaries are executed by privileged users, as well as system services, and restrictive permissions are necessary to ensure execution of these programs cannot be co-opted.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_binary_dirs

Identifiers and References

References: 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-001499, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-5(6), CM-5(6).1, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000259-GPOS-00100, SV-230257r792862_rule

Remediation Shell script ⇲

    DIRS="/bin /usr/bin /usr/local/bin /sbin /usr/sbin /usr/local/sbin /usr/libexec"
    for dirPath in $DIRS; do
    	find "$dirPath" -perm /022 -exec chmod go-w '{}' \;
    done

Remediation Ansible snippet ⇲

Complexity: | medium
Disruption: | medium
Reboot: | false
Strategy: | restrict

    - name: Read list of world and group writable system executables
      ansible.builtin.command: find /bin /usr/bin /usr/local/bin /sbin /usr/sbin /usr/local/sbin
        /usr/libexec -perm /022 -type f
      register: world_writable_library_files
      changed_when: false
      failed_when: false
      check_mode: false
      tags:
      - DISA-STIG-RHEL-08-010300
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-5(6)
      - NIST-800-53-CM-5(6).1
      - NIST-800-53-CM-6(a)
      - file_permissions_binary_dirs
      - medium_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Remove world/group writability of system executables
      ansible.builtin.file:
        path: '{{ item }}'
        mode: go-w
        state: file
      with_items: '{{ world_writable_library_files.stdout_lines }}'
      when: world_writable_library_files.stdout_lines | length > 0
      tags:
      - DISA-STIG-RHEL-08-010300
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-5(6)
      - NIST-800-53-CM-5(6).1
      - NIST-800-53-CM-6(a)
      - file_permissions_binary_dirs
      - medium_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

#### Rule Verify that Shared Library Files Have Restrictive Permissions [ref]

System-wide shared library files, which are linked to executables during process load time or run time, are stored in the following directories by default:

    /lib
    /lib64
    /usr/lib
    /usr/lib64

Kernel modules, which can be added to the kernel during runtime, are stored in `/lib/modules`. All files in these directories should not be group-writable or world-writable. If any file in these directories is found to be group-writable or world-writable, correct its permission with the following command:

    $ sudo chmod go-w FILE

Rationale: | Files from shared library directories are loaded into the address space of processes (including privileged ones) or of the kernel itself at runtime. Restrictive permissions are necessary to protect the integrity of the system.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_library_dirs

Identifiers and References

References: 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-001499, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), CM-5(6), CM-5(6).1, AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000259-GPOS-00100, SV-230260r792867_rule

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    find -H /lib/  -perm /g+w,o+w  -type f -regex '^.*$' -exec chmod g-w,o-w {} \;

    find -H /lib64/  -perm /g+w,o+w  -type f -regex '^.*$' -exec chmod g-w,o-w {} \;

    find -H /usr/lib/  -perm /g+w,o+w  -type f -regex '^.*$' -exec chmod g-w,o-w {} \;

    find -H /usr/lib64/  -perm /g+w,o+w  -type f -regex '^.*$' -exec chmod g-w,o-w {} \;

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    - name: Find /lib/ file(s) recursively
      command: find -H /lib/  -perm /g+w,o+w  -type f -regex "^.*$"
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      tags:
      - DISA-STIG-RHEL-08-010330
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-5(6)
      - NIST-800-53-CM-5(6).1
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_permissions_library_dirs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set permissions for /lib/ file(s)
      file:
        path: '{{ item }}'
        mode: g-w,o-w
        state: file
      with_items:
      - '{{ files_found.stdout_lines }}'
      tags:
      - DISA-STIG-RHEL-08-010330
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-5(6)
      - NIST-800-53-CM-5(6).1
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_permissions_library_dirs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find /lib64/ file(s) recursively
      command: find -H /lib64/  -perm /g+w,o+w  -type f -regex "^.*$"
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      tags:
      - DISA-STIG-RHEL-08-010330
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-5(6)
      - NIST-800-53-CM-5(6).1
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_permissions_library_dirs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set permissions for /lib64/ file(s)
      file:
        path: '{{ item }}'
        mode: g-w,o-w
        state: file
      with_items:
      - '{{ files_found.stdout_lines }}'
      tags:
      - DISA-STIG-RHEL-08-010330
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-5(6)
      - NIST-800-53-CM-5(6).1
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_permissions_library_dirs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find /usr/lib/ file(s) recursively
      command: find -H /usr/lib/  -perm /g+w,o+w  -type f -regex "^.*$"
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      tags:
      - DISA-STIG-RHEL-08-010330
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-5(6)
      - NIST-800-53-CM-5(6).1
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_permissions_library_dirs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set permissions for /usr/lib/ file(s)
      file:
        path: '{{ item }}'
        mode: g-w,o-w
        state: file
      with_items:
      - '{{ files_found.stdout_lines }}'
      tags:
      - DISA-STIG-RHEL-08-010330
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-5(6)
      - NIST-800-53-CM-5(6).1
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_permissions_library_dirs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find /usr/lib64/ file(s) recursively
      command: find -H /usr/lib64/  -perm /g+w,o+w  -type f -regex "^.*$"
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      tags:
      - DISA-STIG-RHEL-08-010330
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-5(6)
      - NIST-800-53-CM-5(6).1
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_permissions_library_dirs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set permissions for /usr/lib64/ file(s)
      file:
        path: '{{ item }}'
        mode: g-w,o-w
        state: file
      with_items:
      - '{{ files_found.stdout_lines }}'
      tags:
      - DISA-STIG-RHEL-08-010330
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-5(6)
      - NIST-800-53-CM-5(6).1
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_permissions_library_dirs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

Group SELinux Group contains 2 rules

[ref] SELinux is a feature of the Linux kernel which can be used to guard against misconfigured or compromised programs. SELinux enforces the idea that programs should be limited in what files they can access and what actions they can take.
The default SELinux policy, as configured on Red Hat Enterprise Linux 8, has been sufficiently developed and debugged that it should be usable on almost any system with minimal configuration and a small amount of system administrator training. This policy prevents system services - including most of the common network-visible services such as mail servers, FTP servers, and DNS servers - from accessing files which those services have no valid reason to access. This action alone prevents a huge amount of possible damage from network attacks against services, from trojaned software, and so forth.
This guide recommends that SELinux be enabled using the default (targeted) policy on every Red Hat Enterprise Linux 8 system, unless that system has unusual requirements which make a stronger policy appropriate.
For more information on SELinux, see https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/using_selinux.

#### Rule Configure SELinux Policy [ref]

The SELinux `targeted` policy is appropriate for general-purpose desktops and servers, as well as systems in many other roles. To configure the system to use this policy, add or correct the following line in `/etc/selinux/config`:

    SELINUXTYPE=targeted

Other policies, such as `mls`, provide additional security labeling and greater confinement but are not compatible with many general-purpose use cases.

Rationale:

Setting the SELinux policy to `targeted` or a more specialized policy ensures the system will confine processes that are likely to be targeted for exploitation, such as network or system services.
Note: During the development or debugging of SELinux modules, it is common to temporarily place non-production systems in `permissive` mode. In such temporary cases, SELinux policies should be developed, and once work is completed, the system should be reconfigured to `targeted`.

Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_selinux_policytype

Identifiers and References

References: BP28(R66), 1, 11, 12, 13, 14, 15, 16, 18, 3, 4, 5, 6, 8, 9, APO01.06, APO11.04, APO13.01, BAI03.05, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, MEA02.01, 3.1.2, 3.7.2, CCI-002165, CCI-002696, 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e), 4.2.3.4, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.2, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-004-6 R3.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, CIP-007-3 R6.5, AC-3, AC-3(3)(a), AU-9, SC-7(21), DE.AE-1, ID.AM-3, PR.AC-4, PR.AC-5, PR.AC-6, PR.DS-5, PR.PT-1, PR.PT-3, PR.PT-4, 1.2.6, SRG-OS-000445-GPOS-00199, SRG-APP-000233-CTR-000585, 1.6.1.3, SV-230282r854035_rule

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict

    # Remediation is applicable only in certain platforms
    if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

    var_selinux_policy_name='targeted'

    if [ -e "/etc/selinux/config" ] ; then

        LC_ALL=C sed -i "/^SELINUXTYPE=/Id" "/etc/selinux/config"
    else
        touch "/etc/selinux/config"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/selinux/config"

    cp "/etc/selinux/config" "/etc/selinux/config.bak"
    # Insert at the end of the file
    printf '%s\n' "SELINUXTYPE=$var_selinux_policy_name" >> "/etc/selinux/config"
    # Clean up after ourselves.
    rm "/etc/selinux/config.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict

    - name: XCCDF Value var_selinux_policy_name # promote to variable
      set_fact:
        var_selinux_policy_name: !!str targeted
      tags:
        - always

    - name: Configure SELinux Policy
      block:

      - name: Check for duplicate values
        lineinfile:
          path: /etc/selinux/config
          create: true
          regexp: ^SELINUXTYPE=
          state: absent
        check_mode: true
        changed_when: false
        register: dupes

      - name: Deduplicate values from /etc/selinux/config
        lineinfile:
          path: /etc/selinux/config
          create: true
          regexp: ^SELINUXTYPE=
          state: absent
        when: dupes.found is defined and dupes.found > 1

      - name: Insert correct line to /etc/selinux/config
        lineinfile:
          path: /etc/selinux/config
          create: true
          regexp: ^SELINUXTYPE=
          line: SELINUXTYPE={{ var_selinux_policy_name }}
          state: present
      when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - DISA-STIG-RHEL-08-010450
      - NIST-800-171-3.1.2
      - NIST-800-171-3.7.2
      - NIST-800-53-AC-3
      - NIST-800-53-AC-3(3)(a)
      - NIST-800-53-AU-9
      - NIST-800-53-SC-7(21)
      - PCI-DSSv4-1.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
      - selinux_policytype

#### Rule Ensure SELinux State is Enforcing [ref]

The SELinux state should be set to `enforcing` at system boot time. In the file `/etc/selinux/config`, add or correct the following line to configure the system to boot into enforcing mode:

    SELINUX=enforcing

Rationale: | Setting the SELinux state to enforcing ensures SELinux is able to confine potentially compromised processes to the security policy, which is designed to prevent them from causing damage to the system or further elevating their privileges.
Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_selinux_state

Identifiers and References

References: BP28(R4), BP28(R66), 1, 11, 12, 13, 14, 15, 16, 18, 3, 4, 5, 6, 8, 9, APO01.06, APO11.04, APO13.01, BAI03.05, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, MEA02.01, 3.1.2, 3.7.2, CCI-001084, CCI-002165, CCI-002696, 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e), 4.2.3.4, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.2, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-004-6 R3.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, CIP-007-3 R6.5, AC-3, AC-3(3)(a), AU-9, SC-7(21), DE.AE-1, ID.AM-3, PR.AC-4, PR.AC-5, PR.AC-6, PR.DS-5, PR.PT-1, PR.PT-3, PR.PT-4, SRG-OS-000445-GPOS-00199, SRG-OS-000134-GPOS-00068, 1.6.1.5, SV-230240r627750_rule

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict

    # Remediation is applicable only in certain platforms
    if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

    var_selinux_state='enforcing'

    if [ -e "/etc/selinux/config" ] ; then

        LC_ALL=C sed -i "/^SELINUX=/Id" "/etc/selinux/config"
    else
        touch "/etc/selinux/config"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/selinux/config"

    cp "/etc/selinux/config" "/etc/selinux/config.bak"
    # Insert at the end of the file
    printf '%s\n' "SELINUX=$var_selinux_state" >> "/etc/selinux/config"
    # Clean up after ourselves.
    rm "/etc/selinux/config.bak"

    fixfiles onboot
    fixfiles -f relabel

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    - name: XCCDF Value var_selinux_state # promote to variable
      set_fact:
        var_selinux_state: !!str enforcing
      tags:
        - always

    - name: Ensure SELinux State is Enforcing
      block:

      - name: Check for duplicate values
        lineinfile:
          path: /etc/selinux/config
          create: true
          regexp: ^SELINUX=
          state: absent
        check_mode: true
        changed_when: false
        register: dupes

      - name: Deduplicate values from /etc/selinux/config
        lineinfile:
          path: /etc/selinux/config
          create: true
          regexp: ^SELINUX=
          state: absent
        when: dupes.found is defined and dupes.found > 1

      - name: Insert correct line to /etc/selinux/config
        lineinfile:
          path: /etc/selinux/config
          create: true
          regexp: ^SELINUX=
          line: SELINUX={{ var_selinux_state }}
          state: present
      when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - DISA-STIG-RHEL-08-010170
      - NIST-800-171-3.1.2
      - NIST-800-171-3.7.2
      - NIST-800-53-AC-3
      - NIST-800-53-AC-3(3)(a)
      - NIST-800-53-AU-9
      - NIST-800-53-SC-7(21)
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy
      - selinux_state

Group Services Group contains 5 groups and 13 rules

[ref] The best protection against vulnerable software is running less software. This section describes how to review the software which Red Hat Enterprise Linux 8 installs on a system and disable software which is not needed. It then enumerates the software packages installed on a default Red Hat Enterprise Linux 8 system and provides guidance about which ones can be safely disabled.
Red Hat Enterprise Linux 8 provides a convenient minimal install option that essentially installs the bare necessities for a functional system. When building Red Hat Enterprise Linux 8 systems, it is highly recommended to select the minimal packages and then build up the system from there.

Group Base Services Group contains 1 rule
[ref] This section addresses the base services that are installed on a Red Hat Enterprise Linux 8 default installation which are not covered in other sections. Some of these services listen on the network and should be treated with particular discretion. Other services are local system utilities that may or may not be extraneous. In general, system services should be disabled if not required.

#### Rule Disable Automatic Bug Reporting Tool (abrtd) [ref]

The Automatic Bug Reporting Tool (`abrtd`) daemon collects and reports crash data when an application crash is detected. Using a variety of plugins, abrtd can email crash reports to system administrators, log crash reports to files, or forward crash reports to a centralized issue tracking system such as RHTSupport. The `abrtd` service can be disabled with the following command:

    $ sudo systemctl mask --now abrtd.service

Rationale: | Mishandling crash data could expose sensitive information about vulnerabilities in software executing on the system, as well as sensitive information from within a process's address space or registers.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_service_abrtd_disabled

Identifiers and References

References: 11, 12, 14, 15, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-6(a), PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable

    # Remediation is applicable only in certain platforms
    if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

    SYSTEMCTL_EXEC='/usr/bin/systemctl'
    "$SYSTEMCTL_EXEC" stop 'abrtd.service'
    "$SYSTEMCTL_EXEC" disable 'abrtd.service'
    "$SYSTEMCTL_EXEC" mask 'abrtd.service'
    # Disable socket activation if we have a unit file for it
    if "$SYSTEMCTL_EXEC" -q list-unit-files abrtd.socket; then
        "$SYSTEMCTL_EXEC" stop 'abrtd.socket'
        "$SYSTEMCTL_EXEC" mask 'abrtd.socket'
    fi
    # The service may not be running because it has been started and failed,
    # so let's reset the state so OVAL checks pass.
    # Service should be 'inactive', not 'failed' after reboot though.
    "$SYSTEMCTL_EXEC" reset-failed 'abrtd.service' || true

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable

    - name: Block Disable service abrtd
      block:

      - name: Disable service abrtd
        block:

        - name: Disable service abrtd
          systemd:
            name: abrtd.service
            enabled: 'no'
            state: stopped
            masked: 'yes'
        rescue:

        - name: Intentionally ignored previous 'Disable service abrtd' failure, service
            was already disabled
          meta: noop
      when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - disable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - service_abrtd_disabled

    - name: Unit Socket Exists - abrtd.socket
      command: systemctl -q list-unit-files abrtd.socket
      register: socket_file_exists
      changed_when: false
      failed_when: socket_file_exists.rc not in [0, 1]
      check_mode: false
      when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - disable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - service_abrtd_disabled

    - name: Disable socket abrtd
      systemd:
        name: abrtd.socket
        enabled: 'no'
        state: stopped
        masked: 'yes'
      when:
      - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      - socket_file_exists.stdout_lines is search("abrtd.socket",multiline=True)
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - disable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - service_abrtd_disabled

Remediation OSBuild Blueprint snippet ⇲

    [customizations.services]
    disabled = ["abrtd"]

Remediation Puppet snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable

    include disable_abrtd

    class disable_abrtd {
      service {'abrtd':
        enable => false,
        ensure => 'stopped',
      }
    }

Remediation Kubernetes snippet ⇲

Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable

    apiVersion: machineconfiguration.openshift.io/v1
    kind: MachineConfig
    spec:
      config:
        ignition:
          version: 3.1.0
        systemd:
          units:
          - name: abrtd.service
            enabled: false
            mask: true
          - name: abrtd.socket
            enabled: false
            mask: true

Group Obsolete Services Group contains 1 group and 3 rules

[ref] This section discusses a number of network-visible services which have historically caused problems for system security, and for which disabling or severely limiting the service has been the best available guidance for some time. As a result of this, many of these services are not installed as part of Red Hat Enterprise Linux 8 by default.
Organizations which are running these services should switch to more secure equivalents as soon as possible. If it remains absolutely necessary to run one of these services for legacy reasons, care should be taken to restrict the service as much as possible, for instance by configuring host firewall software such as `iptables` to restrict access to the vulnerable service to only those remote hosts which have a known need to use it.

Group Telnet Group contains 3 rules
[ref] The telnet protocol does not provide confidentiality or integrity for information transmitted on the network. This includes authentication information such as passwords. Organizations which use telnet should be actively working to migrate to a more secure protocol.

#### Rule Uninstall telnet-server Package [ref]

The `telnet-server` package can be removed with the following command:

    $ sudo yum erase telnet-server

Rationale:

It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities are often overlooked and therefore may remain unsecure. They increase the risk to the platform by providing additional attack vectors.
The telnet service provides an unencrypted remote access service which does not provide for the confidentiality and integrity of user passwords or the remote session. If a privileged user were to login using this service, the privileged user password could be compromised.
Removing the `telnet-server` package decreases the risk of the telnet service's accidental (or intentional) activation.

Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_package_telnet-server_removed

Identifiers and References

References: BP28(R1), 11, 12, 14, 15, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, CCI-000381, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, Req-2.2.2, 2.2.4, SRG-OS-000095-GPOS-00049, 2.2.16, SV-230487r627750_rule

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable

    # CAUTION: This remediation script will remove telnet-server
    #	   from the system, and may remove any packages
    #	   that depend on telnet-server. Execute this
    #	   remediation AFTER testing on a non-production
    #	   system!

    if rpm -q --quiet "telnet-server" ; then

        yum remove -y "telnet-server"

    fi

Remediation Anaconda snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable

    package --remove=telnet-server

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable

    - name: Ensure telnet-server is removed
      package:
        name: telnet-server
        state: absent
      tags:
      - DISA-STIG-RHEL-08-040000
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-2.2.2
      - PCI-DSSv4-2.2.4
      - disable_strategy
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - package_telnet-server_removed

Remediation Puppet snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable

    include remove_telnet-server

    class remove_telnet-server {
      package { 'telnet-server':
        ensure => 'purged',
      }
    }

#### Rule Remove telnet Clients [ref]

The telnet client allows users to start connections to other systems via the telnet protocol.
Rationale: | The `telnet` protocol is insecure and unencrypted. The use of an unencrypted transmission medium could allow an unauthorized user to steal credentials. The `ssh` package provides an encrypted session and stronger security and is included in Red Hat Enterprise Linux 8.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_package_telnet_removed
Identifiers and References | References: BP28(R1), 3.1.13, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), A.8.2.3, A.13.1.1, A.13.2.1, A.13.2.3, A.14.1.2, A.14.1.3, 2.2.4, 2.3.4

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable

    # CAUTION: This remediation script will remove telnet
    #	   from the system, and may remove any packages
    #	   that depend on telnet. Execute this
    #	   remediation AFTER testing on a non-production
    #	   system!

    if rpm -q --quiet "telnet" ; then

        yum remove -y "telnet"

    fi

Remediation Anaconda snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable

    package --remove=telnet

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable

    - name: Ensure telnet is removed
      package:
        name: telnet
        state: absent
      tags:
      - NIST-800-171-3.1.13
      - PCI-DSSv4-2.2.4
      - disable_strategy
      - low_complexity
      - low_disruption
      - low_severity
      - no_reboot_needed
      - package_telnet_removed

Remediation Puppet snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable

    include remove_telnet

    class remove_telnet {
      package { 'telnet':
        ensure => 'purged',
      }
    }

#### Rule Disable telnet Service [ref]

Make sure that the activation of the `telnet` service on system boot is disabled. The `telnet` socket can be disabled with the following command:

    $ sudo systemctl mask --now telnet.socket

Warning: If the system relies on `xinetd` to manage telnet sessions, ensure the telnet service is disabled by the following line: `disable = yes`. Note that the xinetd file for telnet is not created automatically, therefore it might have different names.

Rationale: | The telnet protocol uses unencrypted network communication, which means that data from the login session, including passwords and all other information transmitted during the session, can be stolen by eavesdroppers on the network. The telnet protocol is also subject to man-in-the-middle attacks.
Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_service_telnet_disabled

Identifiers and References

References: 1, 11, 12, 14, 15, 16, 3, 5, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.06, DSS06.10, 3.1.13, 3.4.7, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.18.1.4, A.6.2.1, A.6.2.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, CM-7(a), CM-7(b), CM-6(a), IA-5(1)(c), PR.AC-1, PR.AC-3, PR.AC-6, PR.AC-7, PR.IP-1, PR.PT-3, PR.PT-4

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable

    # Remediation is applicable only in certain platforms
    if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

    SYSTEMCTL_EXEC='/usr/bin/systemctl'
    "$SYSTEMCTL_EXEC" stop 'telnet.service'
    "$SYSTEMCTL_EXEC" disable 'telnet.service'
    "$SYSTEMCTL_EXEC" mask 'telnet.service'
    # Disable socket activation if we have a unit file for it
    if "$SYSTEMCTL_EXEC" -q list-unit-files telnet.socket; then
        "$SYSTEMCTL_EXEC" stop 'telnet.socket'
        "$SYSTEMCTL_EXEC" mask 'telnet.socket'
    fi
    # The service may not be running because it has been started and failed,
    # so let's reset the state so OVAL checks pass.
    # Service should be 'inactive', not 'failed' after reboot though.
    "$SYSTEMCTL_EXEC" reset-failed 'telnet.service' || true

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable

    - name: Block Disable service telnet
      block:

      - name: Disable service telnet
        block:

        - name: Disable service telnet
          systemd:
            name: telnet.service
            enabled: 'no'
            state: stopped
            masked: 'yes'
        rescue:

        - name: Intentionally ignored previous 'Disable service telnet' failure, service
            was already disabled
          meta: noop
      when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - NIST-800-171-3.1.13
      - NIST-800-171-3.4.7
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-IA-5(1)(c)
      - disable_strategy
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - service_telnet_disabled

    - name: Unit Socket Exists - telnet.socket
      command: systemctl -q list-unit-files telnet.socket
      register: socket_file_exists
      changed_when: false
      failed_when: socket_file_exists.rc not in [0, 1]
      check_mode: false
      when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - NIST-800-171-3.1.13
      - NIST-800-171-3.4.7
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-IA-5(1)(c)
      - disable_strategy
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - service_telnet_disabled

    - name: Disable socket telnet
      systemd:
        name: telnet.socket
        enabled: 'no'
        state: stopped
        masked: 'yes'
      when:
      - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      - socket_file_exists.stdout_lines is search("telnet.socket",multiline=True)
      tags:
      - NIST-800-171-3.1.13
      - NIST-800-171-3.4.7
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-IA-5(1)(c)
      - disable_strategy
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - service_telnet_disabled

Remediation OSBuild Blueprint snippet ⇲

    [customizations.services]
    disabled = ["telnet"]

Remediation Puppet snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable

    include disable_telnet

    class disable_telnet {
      service {'telnet':
        enable => false,
        ensure => 'stopped',
      }
    }

Remediation Kubernetes snippet ⇲

Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable

    apiVersion: machineconfiguration.openshift.io/v1
    kind: MachineConfig
    spec:
      config:
        ignition:
          version: 3.1.0
        systemd:
          units:
          - name: telnet.service
            enabled: false
            mask: true
          - name: telnet.socket
            enabled: false
            mask: true

Group SSH Server Group contains 1 group and 9 rules

[ref] The SSH protocol is recommended for remote login and remote file transfer. SSH provides confidentiality and integrity for data exchanged between two systems, as well as server authentication, through the use of public key cryptography. The implementation included with the system is called OpenSSH, and more detailed documentation is available from its website, https://www.openssh.com. Its server program is called `sshd` and provided by the RPM package `openssh-server`.

Group Configure OpenSSH Server if Necessary Group contains 9 rules
[ref] If the system needs to act as an SSH server, then certain changes should be made to the OpenSSH daemon configuration file `/etc/ssh/sshd_config`. The following recommendations can be applied to this file. See the `sshd_config(5)` man page for more detailed information.

#### Rule Set SSH Client Alive Count Max to zero [ref]

The SSH server sends at most `ClientAliveCountMax` messages during a SSH session and waits for a response from the SSH client. The option `ClientAliveInterval` configures timeout after each `ClientAliveCountMax` message. If the SSH server does not receive a response from the client, then the connection is considered unresponsive and terminated. To ensure the SSH timeout occurs precisely when the `ClientAliveInterval` is set, set the `ClientAliveCountMax` to value of `0` in `/etc/ssh/sshd_config`:

Rationale: | This ensures a user login will be terminated as soon as the `ClientAliveInterval` is reached.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sshd_set_keepalive_0

Identifiers and References

References: 1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8, 5.5.6, APO13.01, BAI03.01, BAI03.02, BAI03.03, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.1.11, CCI-000879, CCI-001133, CCI-002361, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2, A.12.4.1, A.12.4.3, A.14.1.1, A.14.2.1, A.14.2.5, A.18.1.4, A.6.1.2, A.6.1.5, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-004-6 R2.2.3, CIP-007-3 R5.1, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, AC-2(5), AC-12, AC-17(a), SC-10, CM-6(a), DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.IP-2, Req-8.1.8, SRG-OS-000126-GPOS-00066, SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109, 5.2.13

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    # Remediation is applicable only in certain platforms
    if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

    if [ -e "/etc/ssh/sshd_config" ] ; then

        LC_ALL=C sed -i "/^\s*ClientAliveCountMax\s\+/Id" "/etc/ssh/sshd_config"
    else
        touch "/etc/ssh/sshd_config"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/ssh/sshd_config"

    cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
    # Insert at the beginning of the file
    printf '%s\n' "ClientAliveCountMax 0" > "/etc/ssh/sshd_config"
    cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
    # Clean up after ourselves.
    rm "/etc/ssh/sshd_config.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    - name: Set SSH Client Alive Count Max to zero
      block:

      - name: Check for duplicate values
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*ClientAliveCountMax\s+
          state: absent
        check_mode: true
        changed_when: false
        register: dupes

      - name: Deduplicate values from /etc/ssh/sshd_config
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*ClientAliveCountMax\s+
          state: absent
        when: dupes.found is defined and dupes.found > 1

      - name: Insert correct line to /etc/ssh/sshd_config
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*ClientAliveCountMax\s+
          line: ClientAliveCountMax 0
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.11
      - NIST-800-53-AC-12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-2(5)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-10
      - PCI-DSS-Req-8.1.8
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_keepalive_0

#### Rule Set SSH Client Alive Interval [ref]

SSH allows administrators to set a network responsiveness timeout interval. After this interval has passed, the unresponsive client will be automatically logged out.
To set this timeout interval, edit the following line in `/etc/ssh/sshd_config` as follows:

    ClientAliveInterval 300

The timeout interval is given in seconds. For example, have a timeout of 10 minutes, set interval to 600.
If a shorter timeout has already been set for the login shell, that value will preempt any SSH setting made in `/etc/ssh/sshd_config`. Keep in mind that some processes may stop SSH from correctly detecting that the user is idle.
Warning: SSH disconnecting unresponsive clients will not have desired effect without also configuring ClientAliveCountMax in the SSH service configuration.
Warning: Following conditions may prevent the SSH session to time out:

- Remote processes on the remote machine generates output. As the output has to be transferred over the network to the client, the timeout is reset every time such transfer happens.
- Any `scp` or `sftp` activity by the same user to the host resets the timeout.

Rationale: | Terminating an idle ssh session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been let unattended.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sshd_set_idle_timeout

Identifiers and References

References: BP28(R29), 1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8, 5.5.6, APO13.01, BAI03.01, BAI03.02, BAI03.03, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.1.11, CCI-000879, CCI-001133, CCI-002361, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2, A.12.4.1, A.12.4.3, A.14.1.1, A.14.2.1, A.14.2.5, A.18.1.4, A.6.1.2, A.6.1.5, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-004-6 R2.2.3, CIP-007-3 R5.1, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, CM-6(a), AC-17(a), AC-2(5), AC-12, AC-17(a), SC-10, CM-6(a), DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.IP-2, Req-8.1.8, 8.2.8, SRG-OS-000126-GPOS-00066, SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109, SRG-OS-000395-GPOS-00175, 5.2.20, SV-244525r917886_rule

Remediation Shell script ⇲

    # Remediation is applicable only in certain platforms
    if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && { grep -qP "^ID=[\"']?rhel[\"']?$" "/etc/os-release" && { real="$(grep -P "^VERSION_ID=[\"']?[\w.]+[\"']?$" /etc/os-release | sed "s/^VERSION_ID=[\"']\?\([^\"']\+\)[\"']\?$/\1/")"; expected="8.5"; printf "%s\n%s" "$real" "$expected" | sort -VC; }; }; then

    sshd_idle_timeout_value='300'

    if [ -e "/etc/ssh/sshd_config" ] ; then

        LC_ALL=C sed -i "/^\s*ClientAliveInterval\s\+/Id" "/etc/ssh/sshd_config"
    else
        touch "/etc/ssh/sshd_config"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/ssh/sshd_config"

    cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
    # Insert at the beginning of the file
    printf '%s\n' "ClientAliveInterval $sshd_idle_timeout_value" > "/etc/ssh/sshd_config"
    cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
    # Clean up after ourselves.
    rm "/etc/ssh/sshd_config.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    - name: XCCDF Value sshd_idle_timeout_value # promote to variable
      set_fact:
        sshd_idle_timeout_value: !!str 300
      tags:
        - always

    - name: Set SSH Client Alive Interval
      block:

      - name: Check for duplicate values
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*ClientAliveInterval\s+
          state: absent
        check_mode: true
        changed_when: false
        register: dupes

      - name: Deduplicate values from /etc/ssh/sshd_config
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*ClientAliveInterval\s+
          state: absent
        when: dupes.found is defined and dupes.found > 1

      - name: Insert correct line to /etc/ssh/sshd_config
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*ClientAliveInterval\s+
          line: ClientAliveInterval {{ sshd_idle_timeout_value }}
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when:
      - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      - ansible_distribution == 'RedHat' and ansible_distribution_version is version('8.5',
        '<=')
      tags:
      - CJIS-5.5.6
      - DISA-STIG-RHEL-08-010201
      - NIST-800-171-3.1.11
      - NIST-800-53-AC-12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-2(5)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-10
      - PCI-DSS-Req-8.1.8
      - PCI-DSSv4-8.2.8
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_idle_timeout

#### Rule Disable Host-Based Authentication [ref]

SSH's cryptographic host-based authentication is more secure than `.rhosts` authentication. However, it is not recommended that hosts unilaterally trust one another, even within an organization.
The default SSH configuration disables host-based authentication. The appropriate configuration is used if no value is set for `HostbasedAuthentication`.
To explicitly disable host-based authentication, add or correct the following line in `/etc/ssh/sshd_config`:

    HostbasedAuthentication no

Rationale: | SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_disable_host_auth

Identifiers and References

References: 11, 12, 14, 15, 16, 18, 3, 5, 9, 5.5.6, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.03, DSS06.06, 3.1.12, CCI-000366, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, AC-3, AC-17(a), CM-7(a), CM-7(b), CM-6(a), PR.AC-4, PR.AC-6, PR.IP-1, PR.PT-3, FIA_UAU.1, 8.3.1, SRG-OS-000480-GPOS-00229, 5.2.8

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    # Remediation is applicable only in certain platforms
    if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

    if [ -e "/etc/ssh/sshd_config" ] ; then

        LC_ALL=C sed -i "/^\s*HostbasedAuthentication\s\+/Id" "/etc/ssh/sshd_config"
    else
        touch "/etc/ssh/sshd_config"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/ssh/sshd_config"

    cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
    # Insert at the beginning of the file
    printf '%s\n' "HostbasedAuthentication no" > "/etc/ssh/sshd_config"
    cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
    # Clean up after ourselves.
    rm "/etc/ssh/sshd_config.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    - name: Disable Host-Based Authentication
      block:

      - name: Check for duplicate values
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*HostbasedAuthentication\s+
          state: absent
        check_mode: true
        changed_when: false
        register: dupes

      - name: Deduplicate values from /etc/ssh/sshd_config
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*HostbasedAuthentication\s+
          state: absent
        when: dupes.found is defined and dupes.found > 1

      - name: Insert correct line to /etc/ssh/sshd_config
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*HostbasedAuthentication\s+
          line: HostbasedAuthentication no
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-3
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSSv4-8.3.1
      - disable_host_auth
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

Remediation Kubernetes snippet ⇲

    ---
    apiVersion: machineconfiguration.openshift.io/v1
    kind: MachineConfig
    spec:
      config:
        ignition:
          version: 3.1.0
        storage:
          files:
          - contents:
              source: data:,%23%09%24OpenBSD%3A%20sshd_config%2Cv%201.103%202018%2F04%2F09%2020%3A41%3A22%20tj%20Exp%20%24%0A%0A%23%20This%20is%20the%20sshd%20server%20system-wide%20configuration%20file.%20%20See%0A%23%20sshd_config%285%29%20for%20more%20information.%0A%0A%23%20This%20sshd%20was%20compiled%20with%20PATH%3D%2Fusr%2Flocal%2Fbin%3A%2Fusr%2Fbin%3A%2Fusr%2Flocal%2Fsbin%3A%2Fusr%2Fsbin%0A%0A%23%20The%20strategy%20used%20for%20options%20in%20the%20default%20sshd_config%20shipped%20with%0A%23%20OpenSSH%20is%20to%20specify%20options%20with%20their%20default%20value%20where%0A%23%20possible%2C%20but%20leave%20them%20commented.%20%20Uncommented%20options%20override%20the%0A%23%20default%20value.%0A%0A%23%20If%20you%20want%20to%20change%20the%20port%20on%20a%20SELinux%20system%2C%20you%20have%20to%20tell%0A%23%20SELinux%20about%20this%20change.%0A%23%20semanage%20port%20-a%20-t%20ssh_port_t%20-p%20tcp%20%23PORTNUMBER%0A%23%0A%23Port%2022%0A%23AddressFamily%20any%0A%23ListenAddress%200.0.0.0%0A%23ListenAddress%20%3A%3A%0A%0AHostKey%20%2Fetc%2Fssh%2Fssh_host_rsa_key%0AHostKey%20%2Fetc%2Fssh%2Fssh_host_ecdsa_key%0AHostKey%20%2Fetc%2Fssh%2Fssh_host_ed25519_key%0A%0A%23%20Ciphers%20and%20keying%0ARekeyLimit%20512M%201h%0A%0A%23%20System-wide%20Crypto%20policy%3A%0A%23%20This%20system%20is%20following%20system-wide%20crypto%20policy.%20The%20changes%20to%0A%23%20Ciphers%2C%20MACs%2C%20KexAlgoritms%20and%20GSSAPIKexAlgorithsm%20will%20not%20have%20any%0A%23%20effect%20here.%20They%20will%20be%20overridden%20by%20command-line%20options%20passed%20on%0A%23%20the%20server%20start%20up.%0A%23%20To%20opt%20out%2C%20uncomment%20a%20line%20with%20redefinition%20of%20%20CRYPTO_POLICY%3D%0A%23%20variable%20in%20%20%2Fetc%2Fsysconfig%2Fsshd%20%20to%20overwrite%20the%20policy.%0A%23%20For%20more%20information%2C%20see%20manual%20page%20for%20update-crypto-policies%288%29.%0A%0A%23%20Logging%0A%23SyslogFacility%20AUTH%0ASyslogFacility%20AUTHPRIV%0A%23LogLevel%20INFO%0A%0A%23%20Authentication%3A%0A%0A%23LoginGraceTime%202m%0APermitRootLogin%20no%0AStrictModes%20yes%0A%23MaxAuthTries%206%0A%23MaxSessions%2010%0A%0APubkeyAuthentication%20yes%0A%0A%23%20The%20default%20is%20to%20check%20both%20.ssh%2Fauthorized_keys%20and%20.ssh%2Fauthorized_keys2%0A%23%20but%20this%20is%20overridden%20so%20installations%20will%20only%20check%20.ssh%2Fauthorized_keys%0AAuthorizedKeysFile%09.ssh%2Fauthorized_keys%0A%0A%23AuthorizedPrincipalsFile%20none%0A%0A%23AuthorizedKeysCommand%20none%0A%23AuthorizedKeysCommandUser%20nobody%0A%0A%23%20For%20this%20to%20work%20you%20will%20also%20need%20host%20keys%20in%20%2Fetc%2Fssh%2Fssh_known_hosts%0AHostbasedAuthentication%20no%0A%23%20Change%20to%20yes%20if%20you%20don%27t%20trust%20~%2F.ssh%2Fknown_hosts%20for%0A%23%20HostbasedAuthentication%0AIgnoreUserKnownHosts%20yes%0A%23%20Don%27t%20read%20the%20user%27s%20~%2F.rhosts%20and%20~%2F.shosts%20files%0AIgnoreRhosts%20yes%0A%0A%23%20To%20disable%20tunneled%20clear%20text%20passwords%2C%20change%20to%20no%20here%21%0A%23PasswordAuthentication%20yes%0APermitEmptyPasswords%20no%0APasswordAuthentication%20no%0A%0A%23%20Change%20to%20no%20to%20disable%20s%2Fkey%20passwords%0A%23ChallengeResponseAuthentication%20yes%0AChallengeResponseAuthentication%20no%0A%0A%23%20Kerberos%20options%0AKerberosAuthentication%20no%0A%23KerberosOrLocalPasswd%20yes%0A%23KerberosTicketCleanup%20yes%0A%23KerberosGetAFSToken%20no%0A%23KerberosUseKuserok%20yes%0A%0A%23%20GSSAPI%20options%0AGSSAPIAuthentication%20no%0AGSSAPICleanupCredentials%20no%0A%23GSSAPIStrictAcceptorCheck%20yes%0A%23GSSAPIKeyExchange%20no%0A%23GSSAPIEnablek5users%20no%0A%0A%23%20Set%20this%20to%20%27yes%27%20to%20enable%20PAM%20authentication%2C%20account%20processing%2C%0A%23%20and%20session%20processing.%20If%20this%20is%20enabled%2C%20PAM%20authentication%20will%0A%23%20be%20allowed%20through%20the%20ChallengeResponseAuthentication%20and%0A%23%20PasswordAuthentication.%20%20Depending%20on%20your%20PAM%20configuration%2C%0A%23%20PAM%20authentication%20via%20ChallengeResponseAuthentication%20may%20bypass%0A%23%20the%20setting%20of%20%22PermitRootLogin%20without-password%22.%0A%23%20If%20you%20just%20want%20the%20PAM%20account%20and%20session%20checks%20to%20run%20without%0A%23%20PAM%20authentication%2C%20then%20enable%20this%20but%20set%20PasswordAuthentication%0A%23%20and%20ChallengeResponseAuthentication%20to%20%27no%27.%0A%23%20WARNING%3A%20%27UsePAM%20no%27%20is%20not%20supported%20in%20Fedora%20and%20may%20cause%20several%0A%23%20problems.%0AUsePAM%20yes%0A%0A%23AllowAgentForwarding%20yes%0A%23AllowTcpForwarding%20yes%0A%23GatewayPorts%20no%0AX11Forwarding%20yes%0A%23X11DisplayOffset%2010%0A%23X11UseLocalhost%20yes%0A%23PermitTTY%20yes%0A%0A%23%20It%20is%20recommended%20to%20use%20pam_motd%20in%20%2Fetc%2Fpam.d%2Fsshd%20instead%20of%20PrintMotd%2C%0A%23%20as%20it%20is%20more%20configurable%20and%20versatile%20than%20the%20built-in%20version.%0APrintMotd%20no%0A%0APrintLastLog%20yes%0A%23TCPKeepAlive%20yes%0APermitUserEnvironment%20no%0ACompression%20no%0AClientAliveInterval%20600%0AClientAliveCountMax%200%0A%23UseDNS%20no%0A%23PidFile%20%2Fvar%2Frun%2Fsshd.pid%0A%23MaxStartups%2010%3A30%3A100%0A%23PermitTunnel%20no%0A%23ChrootDirectory%20none%0A%23VersionAddendum%20none%0A%0A%23%20no%20default%20banner%20path%0ABanner%20%2Fetc%2Fissue%0A%0A%23%20Accept%20locale-related%20environment%20variables%0AAcceptEnv%20LANG%20LC_CTYPE%20LC_NUMERIC%20LC_TIME%20LC_COLLATE%20LC_MONETARY%20LC_MESSAGES%0AAcceptEnv%20LC_PAPER%20LC_NAME%20LC_ADDRESS%20LC_TELEPHONE%20LC_MEASUREMENT%0AAcceptEnv%20LC_IDENTIFICATION%20LC_ALL%20LANGUAGE%0AAcceptEnv%20XMODIFIERS%0A%0A%23%20override%20default%20of%20no%20subsystems%0ASubsystem%09sftp%09%2Fusr%2Flibexec%2Fopenssh%2Fsftp-server%0A%0A%23%20Example%20of%20overriding%20settings%20on%20a%20per-user%20basis%0A%23Match%20User%20anoncvs%0A%23%09X11Forwarding%20no%0A%23%09AllowTcpForwarding%20no%0A%23%09PermitTTY%20no%0A%23%09ForceCommand%20cvs%20server%0A%0AUsePrivilegeSeparation%20sandbox
            mode: 0600
            path: /etc/ssh/sshd_config
            overwrite: true

#### Rule Enable SSH Server firewalld Firewall Exception [ref]

If the SSH server is in use, inbound connections to SSH's port should be allowed to permit remote access through SSH. In more restrictive firewalld settings, the SSH port should be added to the proper firewalld zone in order to allow SSH remote access.
To configure `firewalld` to allow `ssh` access, run the following command(s):

    firewall-cmd --permanent --add-service=ssh

Then run the following command to load the newly created rule(s):

    firewall-cmd --reload

Warning: The remediation for this rule uses `firewall-cmd` and `nmcli` tools. Therefore, it will only be executed if `firewalld` and `NetworkManager` services are running. Otherwise, the remediation will be aborted and a informative message will be shown in the remediation report. These respective services will not be started in order to preserve any intentional change in network components related to firewall and network interfaces.
Warning: This rule also checks if the SSH port was modified by the administrator in the firewalld services definitions and is reflecting the expected port number. Although this is checked, fixing the custom ssh.xml file placed by the administrator at /etc/firewalld/services it is not in the scope of the remediation since there is no reliable way to manually change the respective file. If the default SSH port is modified, it is on the administrator responsibility to ensure the firewalld customizations in the service port level are properly configured.

Rationale: | If inbound SSH connections are expected, adding the SSH port to the proper firewalld zone will allow remote access through the SSH port.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_firewalld_sshd_port_enabled
Identifiers and References | References: 3.1.12, 1416, AC-17(a), CM-6(b), CM-7(a), CM-7(b), SRG-OS-000096-GPOS-00050

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    # Remediation is applicable only in certain platforms
    if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

    if ! rpm -q --quiet "firewalld" ; then
        yum install -y "firewalld"
    fi
    if ! rpm -q --quiet "NetworkManager" ; then
        yum install -y "NetworkManager"
    fi
    firewalld_sshd_zone='public'

    if systemctl is-active NetworkManager && systemctl is-active firewalld; then
        # First make sure the SSH service is enabled in run-time for the proper zone.
        # This is to avoid connection issues when new interfaces are addeded to this zone.
        firewall-cmd --zone="$firewalld_sshd_zone" --add-service=ssh

        # This will collect all NetworkManager connections names
        readarray -t nm_connections < <(nmcli -f UUID,TYPE con | grep ethernet | awk '{ print $1 }')
        # If the connection is not yet assigned to a firewalld zone, assign it to the proper zone.
        # This will not change connections which are already assigned to any firewalld zone.
        for connection in "${nm_connections[@]}"; do
            current_zone=$(nmcli -f connection.zone connection show "$connection" | awk '{ print $2}')
            if [ $current_zone = "--" ]; then
                nmcli connection modify "$connection" connection.zone $firewalld_sshd_zone
            fi
        done
        systemctl restart NetworkManager

        # Active zones are zones with at least one interface assigned to it.
        # It is possible that traffic is comming by any active interface and consequently any
        # active zone. So, this make sure all active zones are permanently allowing SSH service.
        readarray -t firewalld_active_zones < <(firewall-cmd --get-active-zones | grep -v interfaces)
        for zone in "${firewalld_active_zones[@]}"; do
            firewall-cmd --permanent --zone="$zone" --add-service=ssh
        done
        firewall-cmd --reload
    else
        echo "
        firewalld and NetworkManager services are not active. Remediation aborted!
        This remediation could not be applied because it depends on firewalld and NetworkManager services running.
        The service is not started by this remediation in order to prevent connection issues."
        exit 1
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure

    - name: XCCDF Value firewalld_sshd_zone # promote to variable
      set_fact:
        firewalld_sshd_zone: !!str public
      tags:
        - always

    - name: Enable SSH Server firewalld Firewall Exception - Ensure firewalld and NetworkManager
        packages are installed
      ansible.builtin.package:
        name: '{{ item }}'
        state: present
      with_items:
      - firewalld
      - NetworkManager
      when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - NIST-800-171-3.1.12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - configure_strategy
      - firewalld_sshd_port_enabled
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Enable SSH Server firewalld Firewall Exception - Collect facts about system
        services
      ansible.builtin.service_facts: null
      register: result_services_states
      when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - NIST-800-171-3.1.12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - configure_strategy
      - firewalld_sshd_port_enabled
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Enable SSH Server firewalld Firewall Exception - Remediation is applicable
        if firewalld and NetworkManager services are running
      block:

      - name: Enable SSH Server firewalld Firewall Exception - Collect NetworkManager
          connections names
        ansible.builtin.shell:
          cmd: nmcli -f UUID,TYPE con | grep ethernet | awk '{ print $1 }'
        register: result_nmcli_cmd_connections_names
        changed_when: false

      - name: Enable SSH Server firewalld Firewall Exception - Collect NetworkManager
          connections zones
        ansible.builtin.shell:
          cmd: nmcli -f connection.zone connection show {{ item | trim }} | awk '{ print
            $2}'
        register: result_nmcli_cmd_connections_zones
        changed_when: false
        with_items:
        - '{{ result_nmcli_cmd_connections_names.stdout_lines }}'

      - name: Enable SSH Server firewalld Firewall Exception - Ensure NetworkManager connections
          are assigned to a firewalld zone
        ansible.builtin.command:
          cmd: nmcli connection modify {{ item.0 }} connection.zone {{ firewalld_sshd_zone
            }}
        register: result_nmcli_cmd_connections_assignment
        with_together:
        - '{{ result_nmcli_cmd_connections_names.stdout_lines }}'
        - '{{ result_nmcli_cmd_connections_zones.results }}'
        when:
        - item.1.stdout == '--'

      - name: Enable SSH Server firewalld Firewall Exception - Ensure NetworkManager connections
          changes are applied
        ansible.builtin.service:
          name: NetworkManager
          state: restarted
        when:
        - result_nmcli_cmd_connections_assignment is changed

      - name: Enable SSH Server firewalld Firewall Exception - Collect firewalld active
          zones
        ansible.builtin.shell:
          cmd: firewall-cmd --get-active-zones | grep -v interfaces
        register: result_firewall_cmd_zones_names
        changed_when: false

      - name: Enable SSH Server firewalld Firewall Exception - Ensure firewalld zones
          allow SSH
        ansible.builtin.command:
          cmd: firewall-cmd --permanent --zone={{ item }} --add-service=ssh
        register: result_nmcli_cmd_connections_assignment
        changed_when:
        - '''ALREADY_ENABLED'' not in result_nmcli_cmd_connections_assignment.stderr'
        with_items:
        - '{{ result_firewall_cmd_zones_names.stdout_lines }}'

      - name: Enable SSH Server firewalld Firewall Exception - Ensure firewalld changes
          are applied
        ansible.builtin.service:
          name: firewalld
          state: reloaded
        when:
        - result_nmcli_cmd_connections_assignment is changed
      when:
      - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      - ansible_facts.services['firewalld.service'].state == 'running'
      - ansible_facts.services['NetworkManager.service'].state == 'running'
      tags:
      - NIST-800-171-3.1.12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - configure_strategy
      - firewalld_sshd_port_enabled
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Enable SSH Server firewalld Firewall Exception - Informative message based
        on services states
      ansible.builtin.assert:
        that:
        - ansible_facts.services['firewalld.service'].state == 'running'
        - ansible_facts.services['NetworkManager.service'].state == 'running'
        fail_msg:
        - firewalld and NetworkManager services are not active. Remediation aborted!
        - This remediation could not be applied because it depends on firewalld and NetworkManager
          services running.
        - The service is not started by this remediation in order to prevent connection
          issues.
        success_msg:
        - Enable SSH Server firewalld Firewall Exception remediation successfully executed
      when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - NIST-800-171-3.1.12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - configure_strategy
      - firewalld_sshd_port_enabled
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

#### Rule Allow Only SSH Protocol 2 [ref]

Only SSH protocol version 2 connections should be permitted. The default setting in `/etc/ssh/sshd_config` is correct, and can be verified by ensuring that the following line appears:

    Protocol 2

Warning: As of `openssh-server` version `7.4` and above, the only protocol supported is version 2, and line

    Protocol 2

in `/etc/ssh/sshd_config` is not necessary.

Rationale: | SSH protocol version 1 is an insecure implementation of the SSH protocol and has many well-known vulnerability exploits. Exploits of the SSH daemon could provide immediate root access to the system.
Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_sshd_allow_only_protocol2

Identifiers and References

References: NT007(R1), 1, 12, 15, 16, 5, 8, 5.5.6, APO13.01, DSS01.04, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.1.13, 3.5.4, CCI-000197, CCI-000366, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.6, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, 0487, 1449, 1506, A.11.2.6, A.13.1.1, A.13.2.1, A.14.1.3, A.18.1.4, A.6.2.1, A.6.2.2, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, CIP-003-8 R4.2, CIP-007-3 R5.1, CIP-007-3 R7.1, CM-6(a), AC-17(a), AC-17(2), IA-5(1)(c), SC-13, MA-4(6), PR.AC-1, PR.AC-3, PR.AC-6, PR.AC-7, PR.PT-4, SRG-OS-000074-GPOS-00042, SRG-OS-000480-GPOS-00227

Remediation Shell script ⇲

    # Remediation is applicable only in certain platforms
    if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^Protocol")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s %s" "$stripped_key" "2"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^Protocol\\>" "/etc/ssh/sshd_config"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^Protocol\\>.*/$escaped_formatted_output/gi" "/etc/ssh/sshd_config"
    else
        if [[ -s "/etc/ssh/sshd_config" ]] && [[ -n "$(tail -c 1 -- "/etc/ssh/sshd_config" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/ssh/sshd_config"
        fi
        cce=""
        printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/ssh/sshd_config" >> "/etc/ssh/sshd_config"
        printf '%s\n' "$formatted_output" >> "/etc/ssh/sshd_config"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    - name: Allow Only SSH Protocol 2
      block:

      - name: Check for duplicate values
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*Protocol\s+
          state: absent
        check_mode: true
        changed_when: false
        register: dupes

      - name: Deduplicate values from /etc/ssh/sshd_config
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*Protocol\s+
          state: absent
        when: dupes.found is defined and dupes.found > 1

      - name: Insert correct line to /etc/ssh/sshd_config
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*Protocol\s+
          line: Protocol 2
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.13
      - NIST-800-171-3.5.4
      - NIST-800-53-AC-17(2)
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-MA-4(6)
      - NIST-800-53-SC-13
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy
      - sshd_allow_only_protocol2

#### Rule Disable SSH Access via Empty Passwords [ref]

Disallow SSH login with empty passwords. The default SSH configuration disables logins with empty passwords. The appropriate configuration is used if no value is set for `PermitEmptyPasswords`.
To explicitly disallow SSH login from accounts with empty passwords, add or correct the following line in `/etc/ssh/sshd_config`:

    PermitEmptyPasswords no

Any accounts with empty passwords should be disabled immediately, and PAM configuration should prevent users from being able to assign themselves empty passwords.

Rationale: | Configuring this setting for the SSH daemon provides additional assurance that remote login via SSH will require a password, even in the event of misconfiguration elsewhere.
Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_sshd_disable_empty_passwords

Identifiers and References

References: NT007(R17), 11, 12, 13, 14, 15, 16, 18, 3, 5, 9, 5.5.6, APO01.06, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, 3.1.1, 3.1.5, CCI-000366, CCI-000766, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 5.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, AC-17(a), CM-7(a), CM-7(b), CM-6(a), PR.AC-4, PR.AC-6, PR.DS-5, PR.IP-1, PR.PT-3, FIA_UAU.1, Req-2.2.4, 2.2.6, SRG-OS-000106-GPOS-00053, SRG-OS-000480-GPOS-00229, SRG-OS-000480-GPOS-00227, 5.2.9, SV-230380r858715_rule

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    # Remediation is applicable only in certain platforms
    if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

    if [ -e "/etc/ssh/sshd_config" ] ; then

        LC_ALL=C sed -i "/^\s*PermitEmptyPasswords\s\+/Id" "/etc/ssh/sshd_config"
    else
        touch "/etc/ssh/sshd_config"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/ssh/sshd_config"

    cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
    # Insert at the beginning of the file
    printf '%s\n' "PermitEmptyPasswords no" > "/etc/ssh/sshd_config"
    cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
    # Clean up after ourselves.
    rm "/etc/ssh/sshd_config.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    - name: Disable SSH Access via Empty Passwords
      block:

      - name: Check for duplicate values
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*PermitEmptyPasswords\s+
          state: absent
        check_mode: true
        changed_when: false
        register: dupes

      - name: Deduplicate values from /etc/ssh/sshd_config
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*PermitEmptyPasswords\s+
          state: absent
        when: dupes.found is defined and dupes.found > 1

      - name: Insert correct line to /etc/ssh/sshd_config
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*PermitEmptyPasswords\s+
          line: PermitEmptyPasswords no
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - CJIS-5.5.6
      - DISA-STIG-RHEL-08-020330
      - NIST-800-171-3.1.1
      - NIST-800-171-3.1.5
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2.6
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_empty_passwords

#### Rule Disable SSH Root Login [ref]

The root user should never be allowed to login to a system directly over a network. To disable root login via SSH, add or correct the following line in `/etc/ssh/sshd_config`:

    PermitRootLogin no

Warning: This rule is disabled on Red Hat Virtualization Hosts and Managers, it will report not applicable. RHV hosts require root access to be managed by RHV Manager.

Rationale: | Even though the communications channel may be encrypted, an additional layer of security is gained by extending the policy of not logging directly on as root. In addition, logging in with a user-specific account provides individual accountability of actions performed on the system and also helps to minimize direct attack attempts on root's password.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sshd_disable_root_login

Identifiers and References

References: BP28(R19), NT007(R21), 1, 11, 12, 13, 14, 15, 16, 18, 3, 5, 5.5.6, APO01.06, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.06, DSS06.10, 3.1.1, 3.1.5, CCI-000366, CCI-000770, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.18.1.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, AC-6(2), AC-17(a), IA-2, IA-2(5), CM-7(a), CM-7(b), CM-6(a), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5, PR.PT-3, FAU_GEN.1, Req-2.2.4, 2.2.6, SRG-OS-000109-GPOS-00056, SRG-OS-000480-GPOS-00227, SRG-APP-000148-CTR-000335, SRG-APP-000190-CTR-000500, 5.2.7, SV-230296r858711_rule

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    # Remediation is applicable only in certain platforms
    if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

    if [ -e "/etc/ssh/sshd_config" ] ; then

        LC_ALL=C sed -i "/^\s*PermitRootLogin\s\+/Id" "/etc/ssh/sshd_config"
    else
        touch "/etc/ssh/sshd_config"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/ssh/sshd_config"

    cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
    # Insert at the beginning of the file
    printf '%s\n' "PermitRootLogin no" > "/etc/ssh/sshd_config"
    cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
    # Clean up after ourselves.
    rm "/etc/ssh/sshd_config.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    - name: Disable SSH Root Login
      block:

      - name: Check for duplicate values
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*PermitRootLogin\s+
          state: absent
        check_mode: true
        changed_when: false
        register: dupes

      - name: Deduplicate values from /etc/ssh/sshd_config
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*PermitRootLogin\s+
          state: absent
        when: dupes.found is defined and dupes.found > 1

      - name: Insert correct line to /etc/ssh/sshd_config
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*PermitRootLogin\s+
          line: PermitRootLogin no
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - CJIS-5.5.6
      - DISA-STIG-RHEL-08-010550
      - NIST-800-171-3.1.1
      - NIST-800-171-3.1.5
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(2)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-IA-2
      - NIST-800-53-IA-2(5)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_root_login

#### Rule Do Not Allow SSH Environment Options [ref]

Ensure that users are not able to override environment variables of the SSH daemon.
The default SSH configuration disables environment processing. The appropriate configuration is used if no value is set for `PermitUserEnvironment`.
To explicitly disable Environment options, add or correct the following `/etc/ssh/sshd_config`:

    PermitUserEnvironment no

Rationale: | SSH environment options potentially allow users to bypass access restriction in some configurations.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sshd_do_not_permit_user_env

Identifiers and References

References: 11, 3, 9, 5.5.6, BAI10.01, BAI10.02, BAI10.03, BAI10.05, 3.1.12, CCI-000366, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.4.3.2, 4.3.4.3.3, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, AC-17(a), CM-7(a), CM-7(b), CM-6(a), PR.IP-1, Req-2.2.4, 2.2.6, SRG-OS-000480-GPOS-00229, 5.2.10, SV-230330r877377_rule

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    # Remediation is applicable only in certain platforms
    if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

    if [ -e "/etc/ssh/sshd_config" ] ; then

        LC_ALL=C sed -i "/^\s*PermitUserEnvironment\s\+/Id" "/etc/ssh/sshd_config"
    else
        touch "/etc/ssh/sshd_config"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/ssh/sshd_config"

    cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
    # Insert at the beginning of the file
    printf '%s\n' "PermitUserEnvironment no" > "/etc/ssh/sshd_config"
    cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
    # Clean up after ourselves.
    rm "/etc/ssh/sshd_config.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    - name: Do Not Allow SSH Environment Options
      block:

      - name: Check for duplicate values
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*PermitUserEnvironment\s+
          state: absent
        check_mode: true
        changed_when: false
        register: dupes

      - name: Deduplicate values from /etc/ssh/sshd_config
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*PermitUserEnvironment\s+
          state: absent
        when: dupes.found is defined and dupes.found > 1

      - name: Insert correct line to /etc/ssh/sshd_config
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*PermitUserEnvironment\s+
          line: PermitUserEnvironment no
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - CJIS-5.5.6
      - DISA-STIG-RHEL-08-010830
      - NIST-800-171-3.1.12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_do_not_permit_user_env

#### Rule Enable SSH Warning Banner [ref]

To enable the warning banner and ensure it is consistent across the system, add or correct the following line in `/etc/ssh/sshd_config`:

    Banner /etc/issue

Another section contains information on how to create an appropriate system-wide warning banner.

Rationale: | The warning message reinforces policy awareness during the logon process and facilitates possible legal action against attackers. Alternatively, systems whose ownership should not be obvious should ensure usage of a banner that does not provide easy attribution.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sshd_enable_warning_banner

Identifiers and References

References: 1, 12, 15, 16, 5.5.6, DSS05.04, DSS05.10, DSS06.10, 3.1.9, CCI-000048, CCI-000050, CCI-001384, CCI-001385, CCI-001386, CCI-001387, CCI-001388, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, AC-8(a), AC-8(c), AC-17(a), CM-6(a), PR.AC-7, FTA_TAB.1, Req-2.2.4, SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088, SV-230225r858694_rule

Remediation Shell script ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    # Remediation is applicable only in certain platforms
    if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

    if [ -e "/etc/ssh/sshd_config" ] ; then

        LC_ALL=C sed -i "/^\s*Banner\s\+/Id" "/etc/ssh/sshd_config"
    else
        touch "/etc/ssh/sshd_config"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/ssh/sshd_config"

    cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
    # Insert at the beginning of the file
    printf '%s\n' "Banner /etc/issue" > "/etc/ssh/sshd_config"
    cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
    # Clean up after ourselves.
    rm "/etc/ssh/sshd_config.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi

Remediation Ansible snippet ⇲

Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict

    - name: Enable SSH Warning Banner
      block:

      - name: Check for duplicate values
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*Banner\s+
          state: absent
        check_mode: true
        changed_when: false
        register: dupes

      - name: Deduplicate values from /etc/ssh/sshd_config
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*Banner\s+
          state: absent
        when: dupes.found is defined and dupes.found > 1

      - name: Insert correct line to /etc/ssh/sshd_config
        lineinfile:
          path: /etc/ssh/sshd_config
          create: true
          regexp: (?i)^\s*Banner\s+
          line: Banner /etc/issue
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
      tags:
      - CJIS-5.5.6
      - DISA-STIG-RHEL-08-010040
      - NIST-800-171-3.1.9
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-8(a)
      - NIST-800-53-AC-8(c)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-2.2.4
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_enable_warning_banner

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