CCE Identifiers in Guide to the Secure Configuration of Red Hat Enterprise Linux 6

CCE ID | Rule Title | Description

CCE-27115-5

Restrict Access to Anonymous Users if Possible

Is there a mission-critical reason for users to transfer files to/from their own accounts using FTP, rather than using a secure protocol like SCP/SFTP? If not, edit the vsftpd configuration file. Add or correct the following configuration option:

    local_enable=NO

If non-anonymous FTP logins are necessary, follow the guidance in the remainder of this section to secure these logins as much as possible.

Limit Users Allowed FTP Access if Necessary

If there is a mission-critical reason for users to access their accounts via the insecure FTP protocol, limit the set of users who are allowed this access. Edit the vsftpd configuration file. Add or correct the following configuration options:

    userlist_enable=YES
    userlist_file=/etc/vsftp.ftpusers
    userlist_deny=NO

Edit the file `/etc/vsftp.ftpusers`. For each user USERNAME who should be allowed to access the system via FTP, add a line containing that user's name:

    USERNAME

If anonymous access is also required, add the anonymous usernames to `/etc/vsftp.ftpusers` as well.

    anonymous
    ftp

Configure Firewalls to Protect the FTP Server

By default, `iptables` blocks access to the ports used by the web server. To configure `iptables` to allow port 21 traffic one must edit `/etc/sysconfig/iptables` and `/etc/sysconfig/ip6tables` (if IPv6 is in use). Add the following line, ensuring that it appears before the final LOG and DROP lines for the INPUT chain:

    -A INPUT -m state --state NEW -p tcp --dport 21 -j ACCEPT

Edit the file `/etc/sysconfig/iptables-config`. Ensure that the space-separated list of modules contains the FTP connection tracking module:

    IPTABLES_MODULES="ip_conntrack_ftp"

CCE-27145-2

Create Warning Banners for All FTP Users

Edit the vsftpd configuration file, which resides at `/etc/vsftpd/vsftpd.conf` by default. Add or correct the following configuration options:

    banner_file=/etc/issue

CCE-27142-9

Enable Logging of All FTP Transactions

Add or correct the following configuration options within the `vsftpd` configuration file, located at `/etc/vsftpd/vsftpd.conf`:

    xferlog_enable=YES
    xferlog_std_format=NO
    log_ftp_protocol=YES

CCE-27117-1

Disable FTP Uploads if Possible

Is there a mission-critical reason for users to upload files via FTP? If not, edit the vsftpd configuration file to add or correct the following configuration options:

    write_enable=NO

If FTP uploads are necessary, follow the guidance in the remainder of this section to secure these transactions as much as possible.

CCE-27411-8 | Place the FTP Home Directory on its Own Partition | By default, the anonymous FTP root is the home directory of the FTP user account. The df command can be used to verify that this directory is on its own partition.

CCE-27187-4

Install vsftpd Package

If this system must operate as an FTP server, install the `vsftpd` package via the standard channels.

    $ sudo yum install vsftpd

CCE-26948-0

Disable vsftpd Service

The `vsftpd` service can be disabled with the following command:

    $ sudo chkconfig vsftpd off

CCE-26687-4

Uninstall vsftpd Package

The `vsftpd` package can be removed with the following command:

    $ sudo yum erase vsftpd

CCE-27075-1

Disable httpd Service

The `httpd` service can be disabled with the following command:

    $ sudo chkconfig httpd off

CCE-27133-8

Uninstall httpd Package

The `httpd` package can be removed with the following command:

    $ sudo yum erase httpd

CCE-27425-8

Set httpd ServerTokens Directive to Prod

`ServerTokens Prod` restricts information in page headers, returning only the word "Apache."
Add or correct the following directive in `/etc/httpd/conf/httpd.conf`:

    ServerTokens Prod

CCE-27586-7

Set httpd ServerSignature Directive to Off

`ServerSignature Off` restricts `httpd` from displaying server version number on error pages.
Add or correct the following directive in `/etc/httpd/conf/httpd.conf`:

    ServerSignature Off

CCE-27487-8

Set Permissions on the /etc/httpd/conf/ Directory

Set permissions on the web server configuration directory to 750:

    $ sudo chmod 750 /etc/httpd/conf/

CCE-27316-9

Set Permissions on All Configuration Files Inside /etc/httpd/conf/

Set permissions on the web server configuration files to 640:

    $ sudo chmod 640 /etc/httpd/conf/*

CCE-27150-2

Set Permissions on the /var/log/httpd/ Directory

Ensure that the permissions on the web server log directory is set to 700:

    $ sudo chmod 700 /var/log/httpd/

This is its default setting.

CCE-27525-5

Install mod_security

Install the `security` module:

    $ sudo yum install mod_security

CCE-27403-5

Install mod_ssl

Install the `mod_ssl` module:

    $ sudo yum install mod_ssl

CCE-27574-3

Restrict Web Directory

The default configuration for the web (`/var/www/html`) Directory allows directory indexing (`Indexes`) and the following of symbolic links (`FollowSymLinks`). Neither of these is recommended.
The `/var/www/html` directory hierarchy should not be viewable via the web, and symlinks should only be followed if the owner of the symlink also owns the linked file.
Ensure that this policy is adhered to by altering the related section of the configuration:

    <Directory "/var/www/html">
    #  ...
       Options SymLinksIfOwnerMatch
    #  ...
    </Directory>

CCE-27565-1 | Restrict Other Critical Directories | All accessible web directories should be configured with similarly restrictive settings. The `Options` directive should be limited to necessary functionality and the `AllowOverride` directive should be used only if needed. The `Order` and `Deny` access control tags should be used to deny access by default, allowing access only where necessary.

CCE-27009-0

Restrict Root Directory

The `httpd` root directory should always have the most restrictive configuration enabled.

    <Directory / >
       Options None
       AllowOverride None
       Order allow,deny
    </Directory>

CCE-27581-8

Limit Available Methods

Web server methods are defined in section 9 of RFC 2616 (http://www.ietf.org/rfc/rfc2616.txt). If a web server does not require the implementation of all available methods, they should be disabled.
Note: `GET` and `POST` are the most common methods. A majority of the others are limited to the WebDAV protocol.

    <Directory /var/www/html>
    # ...
       # Only allow specific methods (this command is case-sensitive!)
       <LimitExcept GET POST>
          Order allow,deny
       </LimitExcept>
    # ...
    </Directory>

CCE-27395-3

Disable LDAP Support

The `ldap` module provides HTTP authentication via an LDAP directory. If its functionality is unnecessary, comment out the related modules:

    #LoadModule ldap_module modules/mod_ldap.so
    #LoadModule authnz_ldap_module modules/mod_authnz_ldap.so

If LDAP is to be used, SSL encryption should be used as well.

CCE-27362-3

Disable CGI Support

The `cgi` module allows HTML to interact with the CGI web programming language.
If this functionality is unnecessary, comment out the module:

    #LoadModule cgi_module modules/mod_cgi.so

If the web server requires the use of CGI, enable `mod_cgi`.

CCE-27276-5

Disable URL Correction on Misspelled Entries

The `speling` module attempts to find a document match by allowing one misspelling in an otherwise failed request. If this functionality is unnecessary, comment out the module:

    #LoadModule speling_module modules/mod_speling.so

This functionality weakens server security by making site enumeration easier.

CCE-27541-2

Disable MIME Magic

The `mime_magic` module provides a second layer of MIME support that in most configurations is likely extraneous. If its functionality is unnecessary, comment out the related module:

    #LoadModule mime_magic_module modules/mod_mime_magic.so

CCE-27468-8

Disable Server Activity Status

The `status` module provides real-time access to statistics on the internal operation of the web server. This may constitute an unnecessary information leak and should be disabled unless necessary. To do so, comment out the related module:

    #LoadModule status_module modules/mod_status.so

If there is a critical need for this module, ensure that access to the status page is properly restricted to a limited set of hosts in the status handler configuration.

CCE-27553-7

Disable HTTP Digest Authentication

The `auth_digest` module provides encrypted authentication sessions. If this functionality is unnecessary, comment out the related module:

    #LoadModule auth_digest_module modules/mod_auth_digest.so

CCE-27329-2

Disable WebDAV (Distributed Authoring and Versioning)

WebDAV is an extension of the HTTP protocol that provides distributed and collaborative access to web content. If its functionality is unnecessary, comment out the related modules:

    #LoadModule dav_module modules/mod_dav.so
    #LoadModule dav_fs_module modules/mod_dav_fs.so

If there is a critical need for WebDAV, extra care should be taken in its configuration. Since DAV access allows remote clients to manipulate server files, any location on the server that is DAV enabled should be protected by access controls.

CCE-27507-3

Disable Web Server Configuration Display

The `info` module creates a web page illustrating the configuration of the web server. This can create an unnecessary security leak and should be disabled. If its functionality is unnecessary, comment out the module:

    #LoadModule info_module modules/mod_info.so

If there is a critical need for this module, use the `Location` directive to provide an access control list to restrict access to the information.

CCE-27442-3

Disable Proxy Support

The `proxy` module provides proxying support, allowing `httpd` to forward requests and serve as a gateway for other servers. If its functionality is unnecessary, comment out the module:

    #LoadModule proxy_module modules/mod_proxy.so

If proxy support is needed, load `mod_proxy` and the appropriate proxy protocol handler module (one of `mod_proxy_http`, `mod_proxy_ftp`, or `mod_proxy_connect`). Additionally, make certain that a server is secure before enabling proxying, as open proxy servers are a security risk. `mod_proxy_balancer` enables load balancing, but requires that `mod status` be enabled.

CCE-26859-9

Disable Cache Support

The `cache` module allows `httpd` to cache data, optimizing access to frequently accessed content. However, it introduces potential security flaws such as the possibility of circumventing `Allow` and `Deny` directives.
If this functionality is unnecessary, comment out the module:

    #LoadModule cache_module modules/mod_cache.so

If caching is required, it should not be enabled for any limited-access content.

CCE-27570-1

Disable HTTP mod_rewrite

The `mod_rewrite` module is very powerful and can protect against certain classes of web attacks. However, it is also very complex and has a significant history of vulnerabilities itself. If its functionality is unnecessary, comment out the related module:

    #LoadModule rewrite_module modules/mod_rewrite.so

CCE-27558-6

Disable Server Side Includes

Server Side Includes provide a method of dynamically generating web pages through the insertion of server-side code. However, the technology is also deprecated and introduces significant security concerns. If this functionality is unnecessary, comment out the related module:

    #LoadModule include_module modules/mod_include.so

If there is a critical need for Server Side Includes, they should be enabled with the option `IncludesNoExec` to prevent arbitrary code execution. Additionally, user supplied data should be encoded to prevent cross-site scripting vulnerabilities.

CCE-RHEL6-CCE-TBD

Configure SSSD's Memory Cache to Expire

SSSD's memory cache should be configured to set to expire records after 1 day. To configure SSSD to expire memory cache, set `memcache_timeout` to `86400` under the `[nss]` section in `/etc/sssd/sssd.conf`. For example:

    [nss]
    memcache_timeout = 86400

CCE-RHEL6-CCE-TBD

Configure SSSD to Expire Offline Credentials

SSSD should be configured to expire offline credentials after 1 day. To configure SSSD to expire offline credentials, set `offline_credentials_expiration` to `1` under the `[pam]` section in `/etc/sssd/sssd.conf`. For example:

    [pam]
    offline_credentials_expiration = 1

CCE-RHEL6-CCE-TBD

Install the SSSD Package

The `sssd` package should be installed. The `sssd` package can be installed with the following command:

    $ sudo yum install sssd

CCE-RHEL6-CCE-TBD

Configure SSSD to Expire SSH Known Hosts

SSSD should be configured to expire keys from known SSH hosts after 1 day. To configure SSSD to known SSH hosts, set `ssh_known_hosts_timeout` to `86400` under the `[ssh]` section in `/etc/sssd/sssd.conf`. For example:

    [ssh]
    ssh_known_hosts_timeout = 86400

CCE-RHEL6-CCE-TBD

Enable the SSSD Service

The SSSD service should be enabled. The `sssd` service can be enabled with the following command:

    $ sudo systemctl enable sssd.service

CCE-27021-5

Disable DHCP Client

For each interface on the system (e.g. eth0), edit `/etc/sysconfig/network-scripts/ifcfg-interface` and make the following changes:

- Correct the BOOTPROTO line to read:

      BOOTPROTO=none

- Add or correct the following lines, substituting the appropriate values based on your site's addressing scheme:

      NETMASK=255.255.255.0
      IPADDR=192.168.1.2
      GATEWAY=192.168.1.1

CCE-27077-7

Deny BOOTP Queries

Unless your network needs to support older BOOTP clients, disable support for the bootp protocol by adding or correcting the global option:

    deny bootp;

CCE-27049-6

Do Not Use Dynamic DNS

To prevent the DHCP server from receiving DNS information from clients, edit `/etc/dhcp/dhcpd.conf`, and add or correct the following global option:

    ddns-update-style none;

Minimize Served Information

Edit /etc/dhcp/dhcpd.conf. Examine each address range section within the file, and ensure that the following options are not defined unless there is an operational need to provide this information via DHCP:

    option domain-name
    option domain-name-servers
    option nis-domain
    option nis-servers
    option ntp-servers
    option routers
    option time-offset

CCE-27106-4

Deny Decline Messages

Edit `/etc/dhcp/dhcpd.conf` and add or correct the following global option to prevent the DHCP server from responding the DHCPDECLINE messages, if possible:

    deny declines;

CCE-26898-7

Configure Logging

Ensure that the following line exists in `/etc/rsyslog.conf`:

    daemon.*           /var/log/daemon.log

Configure logwatch or other log monitoring tools to summarize error conditions reported by the dhcpd process.

CCE-27120-5

Uninstall DHCP Server Package

If the system does not need to act as a DHCP server, the dhcp package can be uninstalled. The `dhcp` package can be removed with the following command:

    $ sudo yum erase dhcp

CCE-27074-4

Disable DHCP Service

The `dhcpd` service should be disabled on any system that does not need to act as a DHCP server. The `dhcpd` service can be disabled with the following command:

    $ sudo chkconfig dhcpd off

Minimize the DHCP-Configured Options

Create the file `/etc/dhcp/dhclient.conf`, and add an appropriate setting for each of the ten configuration settings which can be obtained via DHCP. For each setting, do one of the following:
If the setting should not be configured remotely by the DHCP server, select an appropriate static value, and add the line:

    supersede setting value;

If the setting should be configured remotely by the DHCP server, add the lines:

    request setting;
    require setting;

For example, suppose the DHCP server should provide only the IP address itself and the subnet mask. Then the entire file should look like:

    supersede domain-name "example.com";
    supersede domain-name-servers 192.168.1.2;
    supersede nis-domain "";
    supersede nis-servers "";
    supersede ntp-servers "ntp.example.com ";
    supersede routers 192.168.1.1;
    supersede time-offset -18000;
    request subnet-mask;
    require subnet-mask;

CCE-27093-4

Enable the NTP Daemon

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

    $ sudo chkconfig --level 2345 ntpd on

CCE-26958-9

Specify Additional Remote NTP Servers

Additional NTP servers can be specified for time synchronization in the file `/etc/ntp.conf`. To do so, add additional lines of the following form, substituting the IP address or hostname of a remote NTP server for ntpserver:

    server ntpserver

CCE-27098-3

Specify a Remote NTP Server

To specify a remote NTP server for time synchronization, edit the file `/etc/ntp.conf`. Add or correct the following lines, substituting the IP or hostname of a remote NTP server for ntpserver:

    server ntpserver

This instructs the NTP software to contact that remote server to obtain time data.

CCE-27108-0

Disable Printer Browsing Entirely if Possible

By default, CUPS listens on the network for printer list broadcasts on UDP port 631. This functionality is called printer browsing. To disable printer browsing entirely, edit the CUPS configuration file, located at `/etc/cups/cupsd.conf`, to include the following:

    Browsing Off

CCE-27107-2

Disable Print Server Capabilities

To prevent remote users from potentially connecting to and using locally configured printers, disable the CUPS print server sharing capabilities. To do so, limit how the server will listen for print jobs by removing the more generic port directive from /etc/cups/cupsd.conf:

    Port 631

and replacing it with the `Listen` directive:

    Listen localhost:631

This will prevent remote users from printing to locally configured printers while still allowing local users on the system to print normally.

CCE-26899-5

Disable the CUPS Service

The `cups` service can be disabled with the following command:

    $ sudo chkconfig cups off

CCE-27365-6

Configure SNMP Service to Use Only SNMPv3 or Newer

Edit `/etc/snmp/snmpd.conf`, removing any references to `rocommunity`, `rwcommunity`, or `com2sec`. Upon doing that, restart the SNMP service:

    $ sudo service snmpd restart

CCE-27593-3

Ensure Default Password Is Not Used

Edit `/etc/snmp/snmpd.conf`, remove default community string `public`. Upon doing that, restart the SNMP service:

    $ sudo service snmpd restart

CCE-26332-7

Uninstall net-snmp Package

The `net-snmp` package provides the snmpd service. The `net-snmp` package can be removed with the following command:

    $ sudo yum erase net-snmp

CCE-26906-8

Disable snmpd Service

The `snmpd` service can be disabled with the following command:

    $ sudo chkconfig snmpd off

CCE-27359-9 | Uninstal rsh Package | The `rsh` package contains the client commands for the rsh services

CCE-26865-6

Disable rlogin Service

The `rlogin` service, which is available with the `rsh-server` package and runs as a service through xinetd, should be disabled. The `rlogin` service can be disabled with the following command:

    $ sudo chkconfig rlogin off

CCE-27208-8

Disable rexec Service

The `rexec` service, which is available with the `rsh-server` package and runs as a service through xinetd, should be disabled. The `rexec` service can be disabled with the following command:

    $ sudo chkconfig rexec off

CCE-26994-4

Disable rsh Service

The `rsh` service, which is available with the `rsh-server` package and runs as a service through xinetd, should be disabled. The `rsh` service can be disabled with the following command:

    $ sudo chkconfig rsh off

CCE-27062-9

Uninstall rsh-server Package

The `rsh-server` package can be uninstalled with the following command:

    $ sudo yum erase rsh-server

CCE-27270-8

Remove Rsh Trust Files

The files `/etc/hosts.equiv` and `~/.rhosts` (in each user's home directory) list remote hosts and users that are trusted by the local system when using the rshd daemon. To remove these files, run the following command to delete them from any location:

    $ sudo rm /etc/hosts.equiv

    $ rm ~/.rhosts

CCE-27428-2 | Remove telnet Clients | The telnet client allows users to start connections to other systems via the telnet protocol.

CCE-27073-6

Uninstall telnet-server Package

The `telnet-server` package can be uninstalled with the following command:

    $ sudo yum erase telnet-server

CCE-26836-7

Disable telnet Service

The `telnet` service can be disabled with the following command:

    $ sudo chkconfig telnet off

CCE-26894-6

Disable ypbind Service

The `ypbind` service, which allows the system to act as a client in a NIS or NIS+ domain, should be disabled. The `ypbind` service can be disabled with the following command:

    $ sudo chkconfig ypbind off

CCE-27372-2 | Remove NIS Client | The Network Information Service (NIS), formerly known as Yellow Pages, is a client-server directory service protocol used to distribute system configuration files. The NIS client (`ypbind`) was used to bind a system to an NIS server and receive the distributed configuration files.

CCE-27079-3

Uninstall ypserv Package

The `ypserv` package can be uninstalled with the following command:

    $ sudo yum erase ypserv

CCE-27448-0 | Remove tftp | Trivial File Transfer Protocol (TFTP) is a simple file transfer protocol, typically used to automatically transfer configuration or boot files between systems. TFTP does not support authentication and can be easily hacked. The package `tftp` is a client program that allows for connections to a `tftp` server.

CCE-27055-3

Disable tftp Service

The `tftp` service should be disabled. The `tftp` service can be disabled with the following command:

    $ sudo chkconfig tftp off

CCE-27272-4

Ensure tftp Daemon Uses Secure Mode

If running the `tftp` service is necessary, it should be configured to change its root directory at startup. To do so, ensure `/etc/xinetd.d/tftp` includes `-s` as a command line argument, as shown in the following example (which is also the default):

    server_args = -s /var/lib/tftpboot

CCE-26946-4

Uninstall tftp-server Package

The `tftp-server` package can be removed with the following command:

    $ sudo yum erase tftp-server

CCE-27046-2

Disable xinetd Service

The `xinetd` service can be disabled with the following command:

    $ sudo chkconfig xinetd off

CCE-27005-8

Uninstall xinetd Package

The `xinetd` package can be uninstalled with the following command:

    $ sudo yum erase xinetd

CCE-27373-0 | Uninstall talk Package | The `talk` package contains the client program for the Internet talk protocol, which allows the user to chat with other users on different systems. Talk is a communication program which copies lines from one terminal to the terminal of another user.

CCE-27427-4

Uninstall talk-server Package

The `talk-server` package can be removed with the following command:

    $ sudo yum erase talk-server

CCE-27158-5

Disable anacron Service

The `cronie-anacron` package, which provides `anacron` functionality, is installed by default. The `cronie-anacron` package can be removed with the following command:

    $ sudo yum erase cronie-anacron

CCE-27070-2

Enable cron Service

The `crond` service is used to execute commands at preconfigured times. It is required by almost all systems to perform necessary maintenance tasks, such as notifying root of system activity. The `crond` service can be enabled with the following command:

    $ sudo chkconfig --level 2345 crond on

CCE-27249-2

Disable At Service (atd)

The `at` and `batch` commands can be used to schedule tasks that are meant to be executed only once. This allows delayed execution in a manner similar to cron, except that it is not recurring. The daemon `atd` keeps track of tasks scheduled via `at` and `batch`, and executes them at the specified time. The `atd` service can be disabled with the following command:

    $ sudo chkconfig atd off

CCE-27138-7

Use Root-Squashing on All Exports

If a filesystem is exported using root squashing, requests from root on the client are considered to be unprivileged (mapped to a user such as nobody). This provides some mild protection against remote abuse of an NFS server. Root squashing is enabled by default, and should not be disabled.
Ensure that no line in `/etc/exports` contains the option `no_root_squash`.

CCE-27121-3

Restrict NFS Clients to Privileged Ports

By default, the server NFS implementation requires that all client requests be made from ports less than 1024. If your organization has control over systems connected to its network, and if NFS requests are prohibited at the border firewall, this offers some protection against malicious requests from unprivileged users. Therefore, the default should not be changed.
To ensure that the default has not been changed, ensure no line in `/etc/exports` contains the option `insecure`.

CCE-80505-1 | Ensure All-Squashing Disabled On All Exports | The `all_squash` maps all uids and gids to an anonymous user. This should be disabled by removing any instances of the `all_squash` option from the file `/etc/exports`.

CCE-27167-6

Ensure Insecure File Locking is Not Allowed

By default the NFS server requires secure file-lock requests, which require credentials from the client in order to lock a file. Most NFS clients send credentials with file lock requests, however, there are a few clients that do not send credentials when requesting a file-lock, allowing the client to only be able to lock world-readable files. To get around this, the `insecure_locks` option can be used so these clients can access the desired export. This poses a security risk by potentially allowing the client access to data for which it does not have authorization. Remove any instances of the `insecure_locks` option from the file `/etc/exports`.

CCE-26864-9

Disable Secure RPC Client Service (rpcgssd)

The rpcgssd service manages RPCSEC GSS contexts required to secure protocols that use RPC (most often Kerberos and NFS). The rpcgssd service is the client-side of RPCSEC GSS. If the system does not require secure RPC then this service should be disabled. The `rpcgssd` service can be disabled with the following command:

    $ sudo chkconfig rpcgssd off

CCE-26870-6

Disable RPC ID Mapping Service (rpcidmapd)

The rpcidmapd service is used to map user names and groups to UID and GID numbers on NFSv4 mounts. If NFS is not in use on the local system then this service should be disabled. The `rpcidmapd` service can be disabled with the following command:

    $ sudo chkconfig rpcidmapd off

CCE-27104-9

Disable Network File System Lock Service (nfslock)

The Network File System Lock (nfslock) service starts the required remote procedure call (RPC) processes which allow clients to lock files on the server. If the local system is not configured to mount NFS filesystems then this service should be disabled. The `nfslock` service can be disabled with the following command:

    $ sudo chkconfig nfslock off

CCE-27430-8

Disable RPC Bind service (rpcbind)

The rpcbind utility is a server that converts RPC program numbers into universal addresses. If RPC calls are not made to servers on the local system then this service should be disabled. The `rpcbind` service can be disabled with the following command:

    $ sudo chkconfig rpcbind off

CCE-27137-9

Disable Network File Systems (netfs)

The netfs script manages the boot-time mounting of several types of networked filesystems, of which NFS and Samba are the most common. If these filesystem types are not in use, the script can be disabled, protecting the system somewhat against accidental or malicious changes to `/etc/fstab` and against flaws in the netfs script itself. The `netfs` service can be disabled with the following command:

    $ sudo chkconfig netfs off

CCE-27149-4

Configure lockd to use static TCP port

Configure the `lockd` daemon to use a static TCP port as opposed to letting the RPC Bind service dynamically assign a port. Edit the file `/etc/sysconfig/nfs`. Add or correct the following line:

    LOCKD_TCPPORT=lockd-port

Where `lockd-port` is a port which is not used by any other service on your network.

CCE-27063-7

Configure lockd to use static UDP port

Configure the `lockd` daemon to use a static UDP port as opposed to letting the RPC Bind service dynamically assign a port. Edit the file `/etc/sysconfig/nfs`. Add or correct the following line:

    LOCKD_UDPPORT=lockd-port

Where `lockd-port` is a port which is not used by any other service on your network.

CCE-26889-6

Configure statd to use static port

Configure the `statd` daemon to use a static port as opposed to letting the RPC Bind service dynamically assign a port. Edit the file `/etc/sysconfig/nfs`. Add or correct the following line:

    STATD_PORT=statd-port

Where `statd-port` is a port which is not used by any other service on your network.

CCE-27114-8

Configure mountd to use static port

Configure the `mountd` daemon to use a static port as opposed to letting the RPC Bind service dynamically assign a port. Edit the file `/etc/sysconfig/nfs`. Add or correct the following line:

    MOUNTD_PORT=statd-port

Where `mountd-port` is a port which is not used by any other service on your network.

CCE-26972-0 | Mount Remote Filesystems with nosuid | Add the `nosuid` option to the fourth column of `/etc/fstab` for the line which controls mounting of any NFS mounts.
CCE-27090-0 | Mount Remote Filesystems with nodev | Add the `nodev` option to the fourth column of `/etc/fstab` for the line which controls mounting of any NFS mounts.

CCE-27414-2

Specify UID and GID for Anonymous NFS Connections

To specify the UID and GID for remote root users, edit the `/etc/exports` file and add the following for each export:

    anonuid=value greater than UID_MAX from /etc/login.defs
    anongid=value greater than GID_MAX from /etc/login.defs

Note that a value of "-1" is technically acceptable as this will randomize the `anonuid` and `anongid` values on a Red Hat Enterprise Linux 6 based NFS server. While acceptable from a security perspective, a value of `-1` may cause interoperability issues, particularly with Red Hat Enterprise Linux 7 client systems.

CCE-27199-9

Disable Network File System (nfs)

The Network File System (NFS) service allows remote hosts to mount and interact with shared filesystems on the local system. If the local system is not designated as a NFS server then this service should be disabled. The `nfs` service can be disabled with the following command:

    $ sudo chkconfig nfs off

CCE-27122-1

Disable Secure RPC Server Service (rpcsvcgssd)

The rpcsvcgssd service manages RPCSEC GSS contexts required to secure protocols that use RPC (most often Kerberos and NFS). The rpcsvcgssd service is the server-side of RPCSEC GSS. If the system does not require secure RPC then this service should be disabled. The `rpcsvcgssd` service can be disabled with the following command:

    $ sudo chkconfig rpcsvcgssd off

CCE-27252-6

Disable Control Group Rules Engine (cgred)

The `cgred` service moves tasks into control groups according to parameters set in the `/etc/cgrules.conf` configuration file. The `cgred` service can be disabled with the following command:

    $ sudo chkconfig cgred off

CCE-26913-4

Disable D-Bus IPC Service (messagebus)

D-Bus provides an IPC mechanism used by a growing list of programs, such as those used for Gnome, Bluetooth, and Avahi. Due to these dependencies, disabling D-Bus may not be practical for many systems. The `messagebus` service can be disabled with the following command:

    $ sudo chkconfig messagebus off

CCE-27061-1

Disable Advanced Configuration and Power Interface (acpid)

The Advanced Configuration and Power Interface Daemon (`acpid`) dispatches ACPI events (such as power/reset button depressed) to userspace programs. The `acpid` service can be disabled with the following command:

    $ sudo chkconfig acpid off

CCE-27261-7

Disable Network Router Discovery Daemon (rdisc)

The `rdisc` service implements the client side of the ICMP Internet Router Discovery Protocol (IRDP), which allows discovery of routers on the local subnet. If a router is discovered then the local routing table is updated with a corresponding default route. By default this daemon is disabled. The `rdisc` service can be disabled with the following command:

    $ sudo chkconfig rdisc off

CCE-26973-8

Disable CPU Speed (cpuspeed)

The `cpuspeed` service can adjust the clock speed of supported CPUs based upon the current processing load thereby conserving power and reducing heat. The `cpuspeed` service can be disabled with the following command:

    $ sudo chkconfig cpuspeed off

CCE-27254-2

Disable Network Console (netconsole)

The `netconsole` service is responsible for loading the netconsole kernel module, which logs kernel printk messages over UDP to a syslog server. This allows debugging of problems where disk logging fails and serial consoles are impractical. The `netconsole` service can be disabled with the following command:

    $ sudo chkconfig netconsole off

CCE-27267-4

Disable Certmonger Service (certmonger)

Certmonger is a D-Bus based service that attempts to simplify interaction with certifying authorities on networks which use public-key infrastructure. It is often combined with Red Hat's IPA (Identity Policy Audit) security information management solution to aid in the management of certificates. The `certmonger` service can be disabled with the following command:

    $ sudo chkconfig certmonger off

CCE-27260-9

Disable Quota Netlink (quota_nld)

The `quota_nld` service provides notifications to users of disk space quota violations. It listens to the kernel via a netlink socket for disk quota violations and notifies the appropriate user of the violation using D-Bus or by sending a message to the terminal that the user has last accessed. The `quota_nld` service can be disabled with the following command:

    $ sudo chkconfig quota_nld off

CCE-27259-1

Enable Process Accounting (psacct)

The process accounting service, `psacct`, works with programs including `acct` and `ac` to allow system administrators to view user activity, such as commands issued by users of the system. The `psacct` service can be enabled with the following command:

    $ sudo chkconfig --level 2345 psacct on

CCE-26846-6

Disable Red Hat Network Service (rhnsd)

The Red Hat Network service automatically queries Red Hat Network servers to determine whether there are any actions that should be executed, such as package updates. This only occurs if the system was registered to an RHN server or satellite and managed as such. The `rhnsd` service can be disabled with the following command:

    $ sudo chkconfig rhnsd off

CCE-27193-2

Disable Software RAID Monitor (mdmonitor)

The `mdmonitor` service is used for monitoring a software RAID array; hardware RAID setups do not use this service. The `mdmonitor` service can be disabled with the following command:

    $ sudo chkconfig mdmonitor off

CCE-26990-2

Enable IRQ Balance (irqbalance)

The `irqbalance` service optimizes the balance between power savings and performance through distribution of hardware interrupts across multiple processors. The `irqbalance` service can be enabled with the following command:

    $ sudo chkconfig --level 2345 irqbalance on

CCE-27257-5

Disable Odd Job Daemon (oddjobd)

The `oddjobd` service exists to provide an interface and access control mechanism through which specified privileged tasks can run tasks for unprivileged client applications. Communication with `oddjobd` through the system message bus. The `oddjobd` service can be disabled with the following command:

    $ sudo chkconfig oddjobd off

CCE-27086-8

Disable Hardware Abstraction Layer Service (haldaemon)

The Hardware Abstraction Layer Daemon (`haldaemon`) collects and maintains information about the system's hardware configuration. This service is required on a workstation running a desktop environment, and may be necessary on any system which deals with removable media or devices. The `haldaemon` service can be disabled with the following command:

    $ sudo chkconfig haldaemon off

CCE-26853-2

Disable SMART Disk Monitoring Service (smartd)

SMART (Self-Monitoring, Analysis, and Reporting Technology) is a feature of hard drives that allows them to detect symptoms of disk failure and relay an appropriate warning. The `smartd` service can be disabled with the following command:

    $ sudo chkconfig smartd off

CCE-26928-2

Disable Apache Qpid (qpidd)

The `qpidd` service provides high speed, secure, guaranteed delivery services. It is an implementation of the Advanced Message Queuing Protocol. By default the qpidd service will bind to port 5672 and listen for connection attempts. The `qpidd` service can be disabled with the following command:

    $ sudo chkconfig qpidd off

CCE-27247-6

Disable Automatic Bug Reporting Tool (abrtd)

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 chkconfig abrtd off

CCE-27250-0

Disable Control Group Config (cgconfig)

Control groups allow an administrator to allocate system resources (such as CPU, memory, network bandwidth, etc) among a defined group (or groups) of processes executing on a system. The `cgconfig` daemon starts at boot and establishes the predefined control groups. The `cgconfig` service can be disabled with the following command:

    $ sudo chkconfig cgconfig off

CCE-27263-3

Disable Cyrus SASL Authentication Daemon (saslauthd)

The `saslauthd` service handles plaintext authentication requests on behalf of the SASL library. The service isolates all code requiring superuser privileges for SASL authentication into a single process, and can also be used to provide proxy authentication services to clients that do not understand SASL based authentication. The `saslauthd` service can be disabled with the following command:

    $ sudo chkconfig saslauthd off

CCE-27256-7

Disable ntpdate Service (ntpdate)

The `ntpdate` service sets the local hardware clock by polling NTP servers when the system boots. It synchronizes to the NTP servers listed in `/etc/ntp/step-tickers` or `/etc/ntp.conf` and then sets the local hardware clock to the newly synchronized system time. The `ntpdate` service can be disabled with the following command:

    $ sudo chkconfig ntpdate off

CCE-26850-8

Disable KDump Kernel Crash Analyzer (kdump)

The `kdump` service provides a kernel crash dump analyzer. It uses the `kexec` system call to boot a secondary kernel ("capture" kernel) following a system crash, which can load information from the crashed kernel for analysis. The `kdump` service can be disabled with the following command:

    $ sudo chkconfig kdump off

CCE-27262-5

Disable Red Hat Subscription Manager Daemon (rhsmcertd)

The Red Hat Subscription Manager (rhsmcertd) periodically checks for changes in the entitlement certificates for a registered system and updates it accordingly. The `rhsmcertd` service can be disabled with the following command:

    $ sudo chkconfig rhsmcertd off

CCE-27258-3

Disable Portreserve (portreserve)

The `portreserve` service is a TCP port reservation utility that can be used to prevent portmap from binding to well known TCP ports that are required for other services. The `portreserve` service can be disabled with the following command:

    $ sudo chkconfig portreserve off

CCE-27265-8

Disable System Statistics Reset Service (sysstat)

The `sysstat` service resets various I/O and CPU performance statistics to zero in order to begin counting from a fresh state at boot time. The `sysstat` service can be disabled with the following command:

    $ sudo chkconfig sysstat off

CCE-27124-7

Disable SSH Support for .rhosts Files

SSH can emulate the behavior of the obsolete rsh command in allowing users to enable insecure access to their accounts via `.rhosts` files.
To ensure this behavior is disabled, add or correct the following line in `/etc/ssh/sshd_config`:

    IgnoreRhosts yes

CCE-27556-0

Limit Users' SSH Access

By default, the SSH configuration allows any user with an account to access the system. In order to specify the users that are allowed to login via SSH and deny all other users, add or correct the following line in the `/etc/ssh/sshd_config` file:

    DenyUsers USER1 USER2

Where `USER1` and `USER2` are valid user names.

CCE-26919-1

Set SSH Idle Timeout Interval

SSH allows administrators to set an idle timeout interval. After this interval has passed, the idle user will be automatically logged out.
To set an idle timeout interval, edit the following line in `/etc/ssh/sshd_config` as follows:

    ClientAliveInterval

The timeout interval is given in seconds. To have a timeout of 15 minutes, set interval to 900.
If a shorter timeout has already been set for the login shell, that value will preempt any SSH setting made here. Keep in mind that some processes may stop SSH from correctly detecting that the user is idle.

CCE-80504-4

Print Last Log

When enabled, SSH will display the date and time of the last successful account logon. To enable LastLog in SSH, add or correct the following line in the `/etc/ssh/sshd_config` file:

    PrintLastLog yes

CCE-27112-2

Enable SSH Warning Banner

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.

CCE-27201-3

Do Not Allow SSH Environment Options

To ensure users are not able to present environment options to the SSH daemon, add or correct the following line in `/etc/ssh/sshd_config`:

    PermitUserEnvironment no

CCE-26887-0

Disable SSH Access via Empty Passwords

To explicitly disallow remote 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.

Use Only Approved MACs

Limit the MACs to those hash algorithms which are FIPS-approved. The following line in `/etc/ssh/sshd_config` demonstrates use of FIPS-approved MACs:

    MACs hmac-sha2-512,hmac-sha2-256,hmac-sha1

The man page `sshd_config(5)` contains a list of supported MACs.

CCE-26555-3

Use Only Approved Ciphers

Limit the ciphers to those algorithms which are FIPS-approved. Counter (CTR) mode is also preferred over cipher-block chaining (CBC) mode. The following line in `/etc/ssh/sshd_config` demonstrates use of FIPS-approved ciphers:

    Ciphers aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc

The man page `sshd_config(5)` contains a list of supported ciphers.

CCE-26282-4

Set SSH Client Alive Count

To ensure the SSH idle timeout occurs precisely when the `ClientAliveCountMax` is set, edit `/etc/ssh/sshd_config` as follows:

    ClientAliveCountMax 0

CCE-27091-8

Disable Host-Based Authentication

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.
To disable host-based authentication, add or correct the following line in `/etc/ssh/sshd_config`:

    HostbasedAuthentication no

CCE-27072-8

Allow Only SSH Protocol 2

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

CCE-27100-7

Disable SSH Root Login

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

CCE-27054-6

Disable SSH Server If Possible (Unusual)

The SSH server service, sshd, is commonly needed. However, if it can be disabled, do so. The `sshd` service can be disabled with the following command:

    $ sudo chkconfig sshd off

This is unusual, as SSH is a common method for encrypted and authenticated remote access.

CCE-27060-3

Remove SSH Server iptables Firewall exception (Unusual)

By default, inbound connections to SSH's port are allowed. If the SSH server is not being used, this exception should be removed from the firewall configuration.
Edit the files `/etc/sysconfig/iptables` and `/etc/sysconfig/ip6tables` (if IPv6 is in use). In each file, locate and delete the line:

    -A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT

This is unusual, as SSH is a common method for encrypted and authenticated remote access.

CCE-27528-9

Disable Zone Transfers from the Nameserver

Is it necessary for a secondary nameserver to receive zone data via zone transfer from the primary server? If not, follow the instructions in this section. If so, see the next section for instructions on protecting zone transfers. Add or correct the following directive within `/etc/named.conf`:

    options {
      allow-transfer { none; };
      ...
    }

CCE-27105-6

Disable Dynamic Updates

Is there a mission-critical reason to enable the risky dynamic update functionality? If not, edit `/etc/named.conf`. For each zone specification, correct the following directive if necessary:

    zone "example.com " IN {
      allow-update { none; };
      ...
    };

CCE-27496-9

Authenticate Zone Transfers

If it is necessary for a secondary nameserver to receive zone data via zone transfer from the primary server, follow the instructions here. Use dnssec-keygen to create a symmetric key file in the current directory:

    $ cd /tmp
    $ sudo dnssec-keygen -a HMAC-MD5 -b 128 -n HOST dns.example.com
    Kdns.example.com .+aaa +iiiii

This output is the name of a file containing the new key. Read the file to find the base64-encoded key string:

    $ sudo cat Kdns.example.com .+NNN +MMMMM .key
    dns.example.com IN KEY 512 3 157 base64-key-string

Add the directives to `/etc/named.conf` on the primary server:

    key zone-transfer-key {
      algorithm hmac-md5;
      secret "base64-key-string ";
    };
    zone "example.com " IN {
      type master;
      allow-transfer { key zone-transfer-key; };
      ...
    };

Add the directives below to `/etc/named.conf` on the secondary nameserver:

    key zone-transfer-key {
      algorithm hmac-md5;
      secret "base64-key-string ";
    };

    server IP-OF-MASTER {
      keys { zone-transfer-key; };
    };

    zone "example.com " IN {
      type slave;
      masters { IP-OF-MASTER ; };
      ...
    };

CCE-26873-0

Disable DNS Server

The `named` service can be disabled with the following command:

    $ sudo chkconfig named off

CCE-27030-6

Uninstall bind Package

To remove the `bind` package, which contains the `named` service, run the following command:

    $ sudo yum erase bind

CCE-26858-1

Uninstall openldap-servers Package

The `openldap-servers` package should be removed if not in use. Is this system the OpenLDAP server? If not, remove the package.

    $ sudo yum erase openldap-servers

The openldap-servers RPM is not installed by default on Red Hat Enterprise Linux 6 systems. It is needed only by the OpenLDAP server, not by the clients which use LDAP for authentication. If the system is not intended for use as an LDAP Server it should be removed.

CCE-26690-8

Configure LDAP Client to Use TLS For All Transactions

Configure LDAP to enforce TLS use. First, edit the file `/etc/pam_ldap.conf`, and add or correct the following lines:

    ssl start_tls

Then review the LDAP server and ensure TLS has been configured.

CCE-27189-0

Configure Certificate Directives for LDAP Use of TLS

Ensure a copy of a trusted CA certificate has been placed in the file `/etc/pki/tls/CA/cacert.pem`. Configure LDAP to enforce TLS use and to trust certificates signed by that CA. First, edit the file `/etc/pam_ldap.conf`, and add or correct either of the following lines:

    tls_cacertdir /etc/pki/tls/CA

or

    tls_cacertfile /etc/pki/tls/CA/cacert.pem

Then review the LDAP server and ensure TLS has been configured.

CCE-80508-5

Configure System to Forward All Mail For The Root Account

Set up an alias for root that forwards to a monitored email address:

    $ sudo echo "root: " >> /etc/aliases
    $ sudo newaliases

CCE-26780-7

Disable Postfix Network Listening

Edit the file `/etc/postfix/main.cf` to ensure that only the following `inet_interfaces` line appears:

    inet_interfaces = localhost

CCE-27508-1

Configure SMTP Greeting Banner

Edit `/etc/postfix/main.cf`, and add or correct the following line, substituting some other wording for the banner information if you prefer:

    smtpd_banner = $myhostname ESMTP

CCE-27515-6

Uninstall Sendmail Package

Sendmail is not the default mail transfer agent and is not installed by default. The `sendmail` package can be removed with the following command:

    $ sudo yum erase sendmail

CCE-26325-1

Enable Postfix Service

The Postfix mail transfer agent is used for local mail delivery within the system. The default configuration only listens for connections to the default SMTP port (port 25) on the loopback interface (127.0.0.1). It is recommended to leave this service enabled for local mail delivery. The `postfix` service can be enabled with the following command:

    $ sudo chkconfig --level 2345 postfix on

CCE-27087-6

Disable Avahi Server Software

The `avahi-daemon` service can be disabled with the following command:

    $ sudo chkconfig avahi-daemon off

CCE-27340-9

Check Avahi Responses' TTL Field

To make Avahi ignore packets unless the TTL field is 255, edit `/etc/avahi/avahi-daemon.conf` and ensure the following line appears in the `[server]` section:

    check-response-ttl=yes

CCE-27526-3

Disable Avahi Publishing

To prevent Avahi from publishing its records, edit `/etc/avahi/avahi-daemon.conf` and ensure the following line appears in the `[publish]` section:

    disable-publishing=yes

CCE-27300-3

Restrict Information Published by Avahi

If it is necessary to publish some information to the network, it should not be joined by any extraneous information, or by information supplied by a non-trusted source on the system. Prevent user applications from using Avahi to publish services by adding or correcting the following line in the `[publish]` section:

    disable-user-service-publishing=yes

Implement as many of the following lines as possible, to restrict the information published by Avahi.

    publish-addresses=no
    publish-hinfo=no
    publish-workstation=no
    publish-domain=no

Inspect the files in the directory `/etc/avahi/services/`. Unless there is an operational need to publish information about each of these services, delete the corresponding file.

CCE-27590-9

Serve Avahi Only via Required Protocol

If you are using only IPv4, edit `/etc/avahi/avahi-daemon.conf` and ensure the following line exists in the `[server]` section:

    use-ipv6=no

Similarly, if you are using only IPv6, disable IPv4 sockets with the line:

    use-ipv4=no

CCE-27308-6

Prevent Other Programs from Using Avahi's Port

To prevent other mDNS stacks from running, edit `/etc/avahi/avahi-daemon.conf` and ensure the following line appears in the `[server]` section:

    disallow-other-stacks=yes

CCE-27119-7

Disable X Windows Startup By Setting Runlevel

Setting the system's runlevel to 3 will prevent automatic startup of the X server. To do so, ensure the following line in `/etc/inittab` features a `3` as shown:

    id:3:initdefault:

CCE-27198-1

Remove the X Windows Package Group

Removing all packages which constitute the X Window System ensures users or malicious software cannot start X. To do so, run the following command:

    $ sudo yum groupremove "X Window System"

CCE-27633-7

Configure Dovecot to Use the SSL Key file

This option tells Dovecot where to find the the mail server's SSL Key.
Edit `/etc/dovecot/conf.d/10-ssl.conf` and add or correct the following line (note: the path below is the default path set by the Dovecot installation. If you are using a different path, ensure you reference the appropriate file):

    ssl_key = </etc/pki/dovecot/private/dovecot.pem

CCE-27144-5

Disable Plaintext Authentication

To prevent Dovecot from attempting plaintext authentication of clients, edit `/etc/dovecot/conf.d/10-auth.conf` and add or correct the following line:

    disable_plaintext_auth = yes

CCE-27571-9

Enable the SSL flag in /etc/dovecot.conf

To allow clients to make encrypted connections the `ssl` flag in Dovecot's configuration file needs to be set to `yes`.
Edit `/etc/dovecot/conf.d/10-ssl.conf` and add or correct the following line:

    ssl = yes

CCE-27459-7

Configure Dovecot to Use the SSL Certificate file

This option tells Dovecot where to find the the mail server's SSL Certificate.
Edit `/etc/dovecot/conf.d/10-ssl.conf` and add or correct the following line (note: the path below is the default path set by the Dovecot installation. If you are using a different path, ensure you reference the appropriate file):

    ssl_cert = </etc/pki/dovecot/certs/dovecot.pem

CCE-26922-5

Disable Dovecot Service

The `dovecot` service can be disabled with the following command:

    $ sudo chkconfig dovecot off

CCE-27039-7

Uninstall dovecot Package

The `dovecot` package can be uninstalled with the following command:

    $ sudo yum erase dovecot

CCE-27143-7

Disable Samba

The `smb` service can be disabled with the following command:

    $ sudo chkconfig smb off

CCE-27102-3

Uninstall samba Package

The `samba` package can be removed with the following command:

    $ sudo yum erase samba

CCE-RHEL6-CCE-TBD

Install the Samba Common Package

The `samba-common` package should be installed. The `samba-common` package can be installed with the following command:

    $ sudo yum install samba-common

CCE-27533-9

Disable Root Access to SMB Shares

Administrators should not use administrator accounts to access Samba file and printer shares. Disable the root user and the wheel administrator group:

    [share]
      invalid users = root @wheel

If administrator accounts cannot be disabled, ensure that local system passwords and Samba service passwords do not match.

CCE-26328-5

Require Client SMB Packet Signing, if using smbclient

To require samba clients running `smbclient` to use packet signing, add the following to the `[global]` section of the Samba configuration file, `/etc/samba/smb.conf`:

    client signing = mandatory

Requiring samba clients such as `smbclient` to use packet signing ensures they can only communicate with servers that support packet signing.

CCE-26792-2

Require Client SMB Packet Signing, if using mount.cifs

Require packet signing of clients who mount Samba shares using the `mount.cifs` program (e.g., those who specify shares in `/etc/fstab`). To do so, ensure signing options (either `sec=krb5i` or `sec=ntlmv2i`) are used.
See the `mount.cifs(8)` man page for more information. A Samba client should only communicate with servers who can support SMB packet signing.

CCE-27146-0

Disable Squid

The `squid` service can be disabled with the following command:

    $ sudo chkconfig squid off

CCE-26977-9

Uninstall squid Package

The `squid` package can be removed with the following command:

    $ sudo yum erase squid

CCE-26801-1

Ensure Logs Sent To Remote Host

To configure rsyslog to send logs to a remote log server, open `/etc/rsyslog.conf` and read and understand the last section of the file, which describes the multiple directives necessary to activate remote logging. Along with these other directives, the system can be configured to forward its logs to a particular log server by adding or correcting one of the following lines, substituting `loghost.example.com` appropriately. The choice of protocol depends on the environment of the system; although TCP and RELP provide more reliable message delivery, they may not be supported in all environments.
To use UDP for log message delivery:

    *.* @loghost.example.com

To use TCP for log message delivery:

    *.* @@loghost.example.com

To use RELP for log message delivery:

    *.* :omrelp:loghost.example.com

CCE-27190-8

Ensure System Log Files Have Correct Permissions

The file permissions for all log files written by `rsyslog` should be set to 600, or more restrictive. These log files are determined by the second part of each Rule line in `/etc/rsyslog.conf` and typically all appear in `/var/log`. For each log file LOGFILE referenced in `/etc/rsyslog.conf`, run the following command to inspect the file's permissions:

    $ ls -l LOGFILE

If the permissions are not 600 or more restrictive, run the following command to correct this:

    $ sudo chmod 0600 LOGFILE

CCE-26812-8

Ensure Log Files Are Owned By Appropriate User

The owner of all log files written by `rsyslog` should be root. These log files are determined by the second part of each Rule line in `/etc/rsyslog.conf` and typically all appear in `/var/log`. For each log file LOGFILE referenced in `/etc/rsyslog.conf`, run the following command to inspect the file's owner:

    $ ls -l LOGFILE

If the owner is not `root`, run the following command to correct this:

    $ sudo chown root LOGFILE

CCE-26821-9

Ensure Log Files Are Owned By Appropriate Group

The group-owner of all log files written by `rsyslog` should be root. These log files are determined by the second part of each Rule line in `/etc/rsyslog.conf` and typically all appear in `/var/log`. For each log file LOGFILE referenced in `/etc/rsyslog.conf`, run the following command to inspect the file's group owner:

    $ ls -l LOGFILE

If the owner is not `root`, run the following command to correct this:

    $ sudo chgrp root LOGFILE

CCE-27236-9

Enable rsyslog to Accept Messages via UDP, if Acting As Log Server

The `rsyslog` daemon should not accept remote messages unless the system acts as a log server. If the system needs to act as a central log server, add the following lines to `/etc/rsyslog.conf` to enable reception of messages over UDP:

    $ModLoad imudp
    $UDPServerRun 514

CCE-26803-7

Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server

The `rsyslog` daemon should not accept remote messages unless the system acts as a log server. To ensure that it is not listening on the network, ensure the following lines are not found in `/etc/rsyslog.conf`:

    $ModLoad imtcp
    $InputTCPServerRun port
    $ModLoad imudp
    $UDPServerRun port
    $ModLoad imrelp
    $InputRELPServerRun port

CCE-27235-1

Enable rsyslog to Accept Messages via TCP, if Acting As Log Server

The `rsyslog` daemon should not accept remote messages unless the system acts as a log server. If the system needs to act as a central log server, add the following lines to `/etc/rsyslog.conf` to enable reception of messages over TCP:

    $ModLoad imtcp
    $InputTCPServerRun 514

CCE-27069-4

Configure Logwatch SplitHosts Line

If `SplitHosts` is set, Logwatch will separate entries by hostname. This makes the report longer but significantly more usable. If it is not set, then Logwatch will not report which host generated a given log entry, and that information is almost always necessary

     SplitHosts = yes

CCE-27197-3

Configure Logwatch HostLimit Line

On a central logserver, you want Logwatch to summarize all syslog entries, including those which did not originate on the logserver itself. The `HostLimit` setting tells Logwatch to report on all hosts, not just the one on which it is running.

     HostLimit = no

CCE-27014-0

Ensure Logrotate Runs Periodically

The `logrotate` utility allows for the automatic rotation of log files. The frequency of rotation is specified in `/etc/logrotate.conf`, which triggers a cron task. To configure logrotate to run daily, add or correct the following line in `/etc/logrotate.conf`:

    # rotate log files frequency
    daily

CCE-27162-7

Disable Logwatch on Clients if a Logserver Exists

Does your site have a central logserver which has been configured to report on logs received from all systems? If so:

    $ sudo rm /etc/cron.daily/0logwatch

If no logserver exists, it will be necessary for each machine to run Logwatch individually. Using a central logserver provides the security and reliability benefits discussed earlier, and also makes monitoring logs easier and less time-intensive for administrators.

CCE-26807-8

Enable rsyslog Service

The `rsyslog` service provides syslog-style logging by default on Red Hat Enterprise Linux 6. The `rsyslog` service can be enabled with the following command:

    $ sudo chkconfig --level 2345 rsyslog on

CCE-26809-4

Ensure rsyslog is Installed

Rsyslog is installed by default. The `rsyslog` package can be installed with the following command:

    $ sudo yum install rsyslog

CCE-27626-1

Install openswan or libreswan Package

The openswan and libreswan packages provide an implementation of IPsec and IKE, which permits the creation of secure tunnels over untrusted networks. The `openswan` package can be installed with the following command:

    $ sudo yum install openswan

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

    $ sudo yum install libreswan

CCE-27186-6

Set Default iptables Policy for Forwarded Packets

To set the default policy to DROP (instead of ACCEPT) for the built-in FORWARD chain which processes packets that will be forwarded from one interface to another, add or correct the following line in `/etc/sysconfig/iptables`:

    :FORWARD DROP [0:0]

CCE-26444-0

Set Default iptables Policy for Incoming Packets

To set the default policy to DROP (instead of ACCEPT) for the built-in INPUT chain which processes incoming packets, add or correct the following line in `/etc/sysconfig/iptables`:

    :INPUT DROP [0:0]

CCE-27006-6

Verify ip6tables Enabled if Using IPv6

The `ip6tables` service can be enabled with the following command:

    $ sudo chkconfig --level 2345 ip6tables on

CCE-27317-7

Set Default ip6tables Policy for Incoming Packets

To set the default policy to DROP (instead of ACCEPT) for the built-in INPUT chain which processes incoming packets, add or correct the following line in `/etc/sysconfig/ip6tables`:

    :INPUT DROP [0:0]

If changes were required, reload the ip6tables rules:

    $ sudo service ip6tables reload

CCE-27018-1

Verify iptables Enabled

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

    $ sudo chkconfig --level 2345 iptables on

CCE-RHEL6-CCE-TBD

Configure Kernel Parameter for Accepting Source-Routed Packets for Interfaces By Default

To set the runtime status of the `net.ipv6.conf.default.accept_source_route` kernel parameter, run the following command:

    $ sudo sysctl -w net.ipv6.conf.default.accept_source_route=0

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    net.ipv6.conf.default.accept_source_route = 0

CCE-RHEL6-CCE-TBD

Configure Kernel Parameter for Accepting Source-Routed Packets for All Interfaces

To set the runtime status of the `net.ipv6.conf.all.accept_source_route` kernel parameter, run the following command:

    $ sudo sysctl -w net.ipv6.conf.all.accept_source_route=0

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    net.ipv6.conf.all.accept_source_route = 0

CCE-RHEL6-CCE-TBD

Disable Kernel Parameter for IPv6 Forwarding

To set the runtime status of the `net.ipv6.conf.all.forwarding` kernel parameter, run the following command:

    $ sudo sysctl -w net.ipv6.conf.all.forwarding=0

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    net.ipv6.conf.all.forwarding = 0

CCE-RHEL6-CCE-TBD

Configure Accepting IPv6 Redirects By Default

To set the runtime status of the `net.ipv6.conf.all.accept_redirects` kernel parameter, run the following command:

    $ sudo sysctl -w net.ipv6.conf.all.accept_redirects=0

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    net.ipv6.conf.all.accept_redirects = 0

CCE-27164-3

Configure Accepting IPv6 Router Advertisements

To set the runtime status of the `net.ipv6.conf.default.accept_ra` kernel parameter, run the following command:

    $ sudo sysctl -w net.ipv6.conf.default.accept_ra=0

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    net.ipv6.conf.default.accept_ra = 0

CCE-RHEL6-CCE-TBD

Configure Accepting IPv6 Router Advertisements

To set the runtime status of the `net.ipv6.conf.all.accept_ra` kernel parameter, run the following command:

    $ sudo sysctl -w net.ipv6.conf.all.accept_ra=0

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    net.ipv6.conf.all.accept_ra = 0

CCE-27166-8

Configure Accepting IPv6 Redirects By Default

To set the runtime status of the `net.ipv6.conf.default.accept_redirects` kernel parameter, run the following command:

    $ sudo sysctl -w net.ipv6.conf.default.accept_redirects=0

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    net.ipv6.conf.default.accept_redirects = 0

CCE-27234-4

Manually Assign IPv6 Router Address

Edit the file `/etc/sysconfig/network-scripts/ifcfg-interface`, and add or correct the following line (substituting your gateway IP as appropriate):

    IPV6_DEFAULTGW=2001:0DB8::0001

Router addresses should be manually set and not accepted via any auto-configuration or router advertisement.

CCE-27233-6

Manually Assign Global IPv6 Address

To manually assign an IP address for an interface, edit the file `/etc/sysconfig/network-scripts/ifcfg-interface`. Add or correct the following line (substituting the correct IPv6 address):

    IPV6ADDR=2001:0DB8::ABCD/64

Manually assigning an IP address is preferable to accepting one from routers or from the network otherwise. The example address here is an IPv6 address reserved for documentation purposes, as defined by RFC3849.

CCE-27154-4

Use Privacy Extensions for Address

To introduce randomness into the automatic generation of IPv6 addresses, add or correct the following line in `/etc/sysconfig/network-scripts/ifcfg-interface`:

    IPV6_PRIVACY=rfc3041

Automatically-generated IPv6 addresses are based on the underlying hardware (e.g. Ethernet) address, and so it becomes possible to track a piece of hardware over its lifetime using its traffic. If it is important for a system's IP address to not trivially reveal its hardware address, this setting should be applied.

CCE-27161-9

Disable Interface Usage of IPv6

To disable interface usage of IPv6, add or correct the following lines in `/etc/sysconfig/network`:

    NETWORKING_IPV6=no
    IPV6INIT=no

CCE-27232-8

Disable Support for RPC IPv6

RPC services for NFSv4 try to load transport modules for `udp6` and `tcp6` by default, even if IPv6 has been disabled in `/etc/modprobe.d`. To prevent RPC services such as `rpc.mountd` from attempting to start IPv6 network listeners, remove or comment out the following two lines in `/etc/netconfig`:

    udp6       tpi_clts      v     inet6    udp     -       -
    tcp6       tpi_cots_ord  v     inet6    tcp     -       -

CCE-27153-6

Disable IPv6 Networking Support Automatic Loading

To prevent the IPv6 kernel module (`ipv6`) from binding to the IPv6 networking stack, add the following line to `/etc/modprobe.d/disabled.conf` (or another file in `/etc/modprobe.d`):

    options ipv6 disable=1

This permits the IPv6 module to be loaded (and thus satisfy other modules that depend on it), while disabling support for the IPv6 protocol.

CCE-26983-7

Configure Kernel Parameter for Accepting Source-Routed Packets By Default

To set the runtime status of the `net.ipv4.conf.default.accept_source_route` kernel parameter, run the following command:

    $ sudo sysctl -w net.ipv4.conf.default.accept_source_route=0

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    net.ipv4.conf.default.accept_source_route = 0

CCE-26993-6

Configure Kernel Parameter to Ignore Bogus ICMP Error Responses

To set the runtime status of the `net.ipv4.icmp_ignore_bogus_error_responses` kernel parameter, run the following command:

    $ sudo sysctl -w net.ipv4.icmp_ignore_bogus_error_responses=1

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    net.ipv4.icmp_ignore_bogus_error_responses = 1

CCE-27015-7

Configure Kernel Parameter for Accepting ICMP Redirects By Default

To set the runtime status of the `net.ipv4.conf.default.accept_redirects` kernel parameter, run the following command:

    $ sudo sysctl -w net.ipv4.conf.default.accept_redirects=0

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    net.ipv4.conf.default.accept_redirects = 0

CCE-26915-9

Configure Kernel Parameter to Use Reverse Path Filtering by Default

To set the runtime status of the `net.ipv4.conf.default.rp_filter` kernel parameter, run the following command:

    $ sudo sysctl -w net.ipv4.conf.default.rp_filter=1

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    net.ipv4.conf.default.rp_filter = 1

CCE-26854-0

Configure Kernel Parameter for Accepting Secure Redirects for All Interfaces

To set the runtime status of the `net.ipv4.conf.all.secure_redirects` kernel parameter, run the following command:

    $ sudo sysctl -w net.ipv4.conf.all.secure_redirects=0

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    net.ipv4.conf.all.secure_redirects = 0

CCE-27053-8

Configure Kernel Parameter to Use TCP Syncookies

To set the runtime status of the `net.ipv4.tcp_syncookies` kernel parameter, run the following command:

    $ sudo sysctl -w net.ipv4.tcp_syncookies=1

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    net.ipv4.tcp_syncookies = 1

CCE-27027-2

Configure Kernel Parameter for Accepting ICMP Redirects for All Interfaces

To set the runtime status of the `net.ipv4.conf.all.accept_redirects` kernel parameter, run the following command:

    $ sudo sysctl -w net.ipv4.conf.all.accept_redirects=0

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    net.ipv4.conf.all.accept_redirects = 0

CCE-27066-0

Configure Kernel Parameter to Log Martian Packets

To set the runtime status of the `net.ipv4.conf.all.log_martians` kernel parameter, run the following command:

    $ sudo sysctl -w net.ipv4.conf.all.log_martians=1

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    net.ipv4.conf.all.log_martians = 1

CCE-26979-5

Configure Kernel Parameter to Use Reverse Path Filtering for All Interfaces

To set the runtime status of the `net.ipv4.conf.all.rp_filter` kernel parameter, run the following command:

    $ sudo sysctl -w net.ipv4.conf.all.rp_filter=1

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    net.ipv4.conf.all.rp_filter = 1

CCE-26883-9

Configure Kernel Parameter to Ignore ICMP Broadcast Echo Requests

To set the runtime status of the `net.ipv4.icmp_echo_ignore_broadcasts` kernel parameter, run the following command:

    $ sudo sysctl -w net.ipv4.icmp_echo_ignore_broadcasts=1

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    net.ipv4.icmp_echo_ignore_broadcasts = 1

CCE-26831-8

Configure Kernel Parameter for Accepting Secure Redirects By Default

To set the runtime status of the `net.ipv4.conf.default.secure_redirects` kernel parameter, run the following command:

    $ sudo sysctl -w net.ipv4.conf.default.secure_redirects=0

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    net.ipv4.conf.default.secure_redirects = 0

CCE-27037-1

Configure Kernel Parameter for Accepting Source-Routed Packets for All Interfaces

To set the runtime status of the `net.ipv4.conf.all.accept_source_route` kernel parameter, run the following command:

    $ sudo sysctl -w net.ipv4.conf.all.accept_source_route=0

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    net.ipv4.conf.all.accept_source_route = 0

CCE-26866-4

Disable Kernel Parameter for IP Forwarding

To set the runtime status of the `net.ipv4.ip_forward` kernel parameter, run the following command:

    $ sudo sysctl -w net.ipv4.ip_forward=0

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    net.ipv4.ip_forward = 0

CCE-27004-1

Disable Kernel Parameter for Sending ICMP Redirects for All Interfaces

To set the runtime status of the `net.ipv4.conf.all.send_redirects` kernel parameter, run the following command:

    $ sudo sysctl -w net.ipv4.conf.all.send_redirects=0

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    net.ipv4.conf.all.send_redirects = 0

CCE-27001-7

Disable Kernel Parameter for Sending ICMP Redirects by Default

To set the runtime status of the `net.ipv4.conf.default.send_redirects` kernel parameter, run the following command:

    $ sudo sysctl -w net.ipv4.conf.default.send_redirects=0

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    net.ipv4.conf.default.send_redirects = 0

CCE-26448-1

Disable DCCP Support

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 a file in the directory `/etc/modprobe.d`:

    install dccp /bin/true

CCE-26239-4

Disable RDS Support

The Reliable Datagram Sockets (RDS) protocol is a transport layer protocol designed to provide reliable high- bandwidth, low-latency communications between nodes in a cluster. To configure the system to prevent the `rds` kernel module from being loaded, add the following line to a file in the directory `/etc/modprobe.d`:

    install rds /bin/true

CCE-26410-1

Disable SCTP Support

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 a file in the directory `/etc/modprobe.d`:

    install sctp /bin/true

CCE-26696-5

Disable TIPC Support

The Transparent Inter-Process Communication (TIPC) protocol is designed to provide communications between nodes in a cluster. To configure the system to prevent the `tipc` kernel module from being loaded, add the following line to a file in the directory `/etc/modprobe.d`:

    install tipc /bin/true

CCE-26763-3

Disable Bluetooth Kernel Modules

The kernel's module loading system can be configured to prevent loading of the Bluetooth module. Add the following to the appropriate `/etc/modprobe.d` configuration file to prevent the loading of the Bluetooth module:

    install bluetooth /bin/true

CCE-26878-9 | Disable WiFi or Bluetooth in BIOS | Some systems that include built-in wireless support offer the ability to disable the device through the BIOS. This is system-specific; consult your hardware manual or explore the BIOS setup during boot.

CCE-27081-9

Disable Bluetooth Service

The `bluetooth` service can be disabled with the following command:

    $ sudo chkconfig bluetooth off

    $ sudo service bluetooth stop

CCE-27057-9

Deactivate Wireless Network Interfaces

Deactivating wireless network interfaces should prevent normal usage of the wireless capability.
First, identify the interfaces available with the command:

    $ ifconfig -a

Additionally, the following command may be used to determine whether wireless support is included for a particular interface, though this may not always be a clear indicator:

    $ iwconfig

After identifying any wireless interfaces (which may have names like `wlan0`, `ath0`, `wifi0`, `em1` or `eth0`), deactivate the interface with the command:

    $ sudo ifdown interface

These changes will only last until the next reboot. To disable the interface for future boots, remove the appropriate interface file from `/etc/sysconfig/network-scripts`:

    $ sudo rm /etc/sysconfig/network-scripts/ifcfg-interface

CCE-27152-8

Ensure System is Not Acting as a Network Sniffer

The system should not be acting as a network sniffer, which can capture all traffic on the network to which it is connected. Run the following to determine if any interface is running in promiscuous mode:

    $ ip link | grep PROMISC

CCE-27151-0

Disable Zeroconf Networking

Zeroconf networking allows the system to assign itself an IP address and engage in IP communication without a statically-assigned address or even a DHCP server. Automatic address assignment via Zeroconf (or DHCP) is not recommended. To disable Zeroconf automatic route assignment in the 169.254.0.0 subnet, add or correct the following line in `/etc/sysconfig/network`:

    NOZEROCONF=yes

CCE-27404-3

Uninstall mcstrans Package

The `mcstransd` daemon provides category label information to client processes requesting information. The label translations are defined in `/etc/selinux/targeted/setrans.conf`. The `mcstrans` package can be removed with the following command:

    $ sudo yum erase mcstrans

CCE-26875-5

Configure SELinux Policy

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=

Other policies, such as `mls`, provide additional security labeling and greater confinement but are not compatible with many general-purpose use cases.

CCE-27421-7

Uninstall setroubleshoot Package

The SETroubleshoot service notifies desktop users of SELinux denials. The service provides information around configuration errors, unauthorized intrusions, and other potential errors. The `setroubleshoot` package can be removed with the following command:

    $ sudo yum erase setroubleshoot

CCE-26956-3 | Ensure SELinux Not Disabled in /etc/grub.conf | SELinux can be disabled at boot time by an argument in `/etc/grub.conf`. Remove any instances of `selinux=0` from the kernel arguments in that file to prevent SELinux from being disabled at boot.

CCE-27111-4

Ensure No Daemons are Unconfined by SELinux

Daemons for which the SELinux policy does not contain rules will inherit the context of the parent process. Because daemons are launched during startup and descend from the `init` process, they inherit the `initrc_t` context.
To check for unconfined daemons, run the following command:

    $ sudo ps -eZ | egrep "initrc" | egrep -vw "tr|ps|egrep|bash|awk" | tr ':' ' ' | awk '{ print $NF }'

It should produce no output in a well-configured system.

CCE-26774-0 | Ensure No Device Files are Unknown to SELinux | Device files, which are used for communication with important system resources, should be labeled with proper SELinux types. If any device files carry the SELinux type `device_t`, report the bug so that policy can be corrected. Supply information about what the device is and what programs use it.

CCE-26969-6

Ensure SELinux State is Enforcing

The SELinux state should be set to `` 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=

CCE-26991-0

Enable the SELinux Context Restoration Service (restorecond)

The `restorecond` service utilizes `inotify` to look for the creation of new files listed in the `/etc/selinux/restorecond.conf` configuration file. When a file is created, `restorecond` ensures the file receives the proper SELinux security context. The `restorecond` service can be enabled with the following command:

    $ sudo chkconfig --level 2345 restorecond on

CCE-26966-2

Ensure that System Accounts Do Not Run a Shell Upon Login

Some accounts are not associated with a human user of the system, and exist to perform some administrative function. 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 UID_MIN, where value of the UID_MIN directive is set in /etc/login.defs configuration file. In the default configuration UID_MIN is set to 500, thus system accounts are those user accounts with a user ID less than 500. The user ID is stored in the third field. If any system account SYSACCT (other than root) has a login shell, disable it with the command:

    $ sudo usermod -s /sbin/nologin SYSACCT

CCE-27125-4

Root Path Must Be Vendor Default

Assuming root shell is bash, edit the following files:

    ~/.profile

    ~/.bashrc

Change any `PATH` variables to the vendor default for root and remove any empty `PATH` entries or references to relative paths.

CCE-26891-2

Direct root Logins Not Allowed

To further limit access to the `root` account, administrators can disable root logins at the console by editing the `/etc/securetty` file. This file lists all devices the root user is allowed to login to. If the file does not exist at all, the root user can login through any communication device on the system, whether via the console or via a raw network interface. This is dangerous as user can login to his machine as root via Telnet, which sends the password in plain text over the network. By default, Red Hat Enteprise Linux's `/etc/securetty` file only allows the root user to login at the console physically attached to the machine. To prevent root from logging in, remove the contents of this file. To prevent direct root logins, remove the contents of this file by typing the following command:

    $ sudo echo > /etc/securetty

CCE-26795-5 | Restrict Web Browser Use for Administrative Accounts | Enforce policy requiring administrative accounts use web browsers only for local service administration.

CCE-80510-1

Ensure that System Accounts Are Locked

Some accounts are not associated with a human user of the system, and exist to perform some administrative function. An attacker should not be able to log into these accounts.
System accounts are those user accounts with a user ID less than UID_MIN, where value of the UID_MIN directive is set in `/etc/login.defs` configuration file. In the default configuration UID_MIN is set to 500, thus system accounts are those user accounts with a user ID less than 500. If any system account SYSACCT (other than root) has an unlocked password, disable it with the command:

    $ sudo passwd -l SYSACCT

CCE-26855-7

Restrict Virtual Console Root Logins

To restrict root logins through the (deprecated) virtual console devices, ensure lines of this form do not appear in `/etc/securetty`:

    vc/1
    vc/2
    vc/3
    vc/4

CCE-27047-0

Restrict Serial Port Root Logins

To restrict root logins on serial ports, ensure lines of this form do not appear in `/etc/securetty`:

    ttyS0
    ttyS1

CCE-26971-2 | Verify Only Root Has UID 0 | 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.
CCE-27038-9 | Prevent Log In to Accounts With Empty Password | If an account is configured for password authentication but does not have an assigned password, it may be possible to log onto the account without authentication. Remove any instances of the `nullok` option in `/etc/pam.d/system-auth` to prevent logins with empty passwords.
CCE-27225-2 | Verify No netrc Files Exist | The `.netrc` files contain login information used to auto-login into FTP servers and reside in the user's home directory. These files may contain unencrypted passwords to remote FTP servers making them susceptible to access by unauthorized users and should not be used. Any `.netrc` files should be removed.
CCE-26476-2 | Verify All Account Password Hashes are Shadowed | If any password hashes are stored in `/etc/passwd` (in the second field, instead of an `x`), 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.
CCE-27379-7 | All GIDs referenced in /etc/passwd must be defined in /etc/group | Add a group to the system for each GID referenced without a corresponding group.

CCE-27002-5

Set Password Minimum Length in login.defs

To specify password length requirements for new accounts, edit the file `/etc/login.defs` and add or correct the following lines:

    PASS_MIN_LEN

As of the DISA Red Hat 6 STIG - Ver 1, Rel 13 (28-OCT-2016), the DoD requirement is now `15`. The FISMA requirement is `12`. If a program consults `/etc/login.defs` and also another PAM module (such as `pam_cracklib`) during a password change operation, then the most restrictive must be satisfied. See PAM section for more information about enforcing password quality requirements.

CCE-27013-2

Set Password Minimum Age

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

    PASS_MIN_DAYS

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

CCE-26985-2

Set Password Maximum Age

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

    PASS_MAX_DAYS

A value of 180 days is sufficient for many environments. The DoD requirement is 60.

CCE-26988-6

Set Password Warning Age

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

The DoD requirement is 7.

CCE-80509-3 | Use Centralized and Automated Authentication | Implement an automated system for managing user accounts that minimizes the risk of errors, either intentional or deliberate. This system should integrate with an existing enterprise user management system, such as one based on Identity Management tools such as Active Directory, Kerberos, Directory Server, etc.
CCE-27609-7 | Ensure All Accounts on the System Have Unique Names | Change usernames, or delete accounts, so each has a unique name.

CCE-27283-1

Set Account Expiration Following Inactivity

To specify the number of days after a password expires (which signifies inactivity) until an account is permanently disabled, add or correct the following lines in `/etc/default/useradd`, substituting `NUM_DAYS` appropriately:

    INACTIVE=

A value of 35 is recommended. If a password is currently on the verge of expiration, then 35 days remain until the account is automatically disabled. However, if the password will not expire for another 60 days, then 95 days could elapse until the account would be automatically disabled. See the `useradd` man page for more information. Determining the inactivity timeout must be done with careful consideration of the length of a "normal" period of inactivity for users in the particular environment. Setting the timeout too low incurs support costs and also has the potential to impact availability of the system to legitimate users.

CCE-27474-6

Assign Expiration Date to Temporary Accounts

In the event temporary or emergency accounts are required, configure the system to terminate them after a documented time period. For every temporary and emergency account, run the following command to set an expiration date on it, substituting `USER` and `YYYY-MM-DD` appropriately:

    $ sudo chage -E YYYY-MM-DD USER

`YYYY-MM-DD` indicates the documented expiration date for the account.

CCE-26940-7

Install the screen Package

To enable console screen locking, install the `screen` package:

    $ sudo yum install screen

Instruct users to begin new terminal sessions with the following command:

    $ screen

The console can now be locked with the following key combination:

    ctrl+a x

CCE-27440-7

Enable Smart Card Login

To enable smart card authentication, consult the documentation at:

- https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Managing_Smart_Cards/enabling-smart-card-login.html

For guidance on enabling SSH to authenticate against a Common Access Card (CAC), consult documentation at:

- https://access.redhat.com/solutions/82273

CCE-27022-3

Verify /etc/grub.conf Group Ownership

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

    $ sudo chgrp root /etc/grub.conf

CCE-26995-1

Verify /etc/grub.conf User Ownership

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

    $ sudo chown root /etc/grub.conf

CCE-26911-8

Set Boot Loader Password

The grub boot loader should have password protection enabled to protect boot-time settings. To do so, select a password and then generate a hash from it by running the following command:

    $ grub-crypt --sha-512

When prompted to enter a password, insert the following line into `/etc/grub.conf` immediately after the header comments. (Use the output from `grub-crypt` as the value of password-hash):

    password --encrypted password-hash

NOTE: To meet FISMA Moderate, the bootloader password MUST differ from the root password.

CCE-26949-8

Verify /boot/grub/grub.conf Permissions

File permissions for `/boot/grub/grub.conf` should be set to 600, which is the default. To properly set the permissions of `/boot/grub/grub.conf`, run the command:

    $ sudo chmod 600 /boot/grub/grub.conf

CCE-27043-9

Disable Interactive Boot

To disable the ability for users to perform interactive startups, perform both of the following:

1. Edit the file `/etc/sysconfig/init`. Add or correct the line:

       PROMPT=no

2. Inspect the kernel boot arguments (which follow the word `kernel`) in `/etc/grub.conf` and ensure the `confirm` argument is not present.

Both the `PROMPT` option of the `/etc/sysconfig/init` file and the `confirm` kernel boot argument of the `/etc/grub.conf` file allow the console user to perform an interactive system startup, in which it is possible to select the set of services which are started on boot.

CCE-27567-7

Disable Ctrl-Alt-Del Reboot Activation

By default, the system includes the following line in `/etc/init/control-alt-delete.conf` to reboot the system when the Ctrl-Alt-Del key sequence is pressed:

    exec /sbin/shutdown -r now "Control-Alt-Delete pressed"

To configure the system to log a message instead of rebooting the system, alter that line to read as follows:

    exec /usr/bin/logger -p security.info "Control-Alt-Delete pressed"

CCE-27040-5

Require Authentication for Single User Mode

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, no authentication is performed if single-user mode is selected.
To require entry of the root password even if the system is started in single-user mode, add or correct the following line in the file `/etc/sysconfig/init`:

    SINGLE=/sbin/sulogin

CCE-26826-8

Ensure that Root's Path Does Not Include Relative Paths or Null Directories

Ensure that none of the directories in root's path is equal to a single `.` character, or that it contains any instances that lead to relative path traversal, such as `..` or beginning a path without the slash (`/`) character. Also ensure that there are no "empty" elements in the path, such as in these examples:

    PATH=:/bin
    PATH=/bin:
    PATH=/bin::/sbin

These empty elements have the same effect as a single `.` character.

CCE-26768-2

Ensure that Root's Path Does Not Include World or Group-Writable Directories

For each element in root's path, run:

    $ sudo ls -ld DIR

and ensure that write permissions are disabled for group and other.

CCE-26371-5

Ensure the Default Umask is Set Correctly in login.defs

To ensure the default umask controlled by `/etc/login.defs` is set properly, add or correct the `UMASK` setting in `/etc/login.defs` to read as follows:

    UMASK

CCE-26917-5

Ensure the Default Bash Umask is Set Correctly

To ensure the default umask for users of the Bash shell is set properly, add or correct the `umask` setting in `/etc/bashrc` to read as follows:

    umask

CCE-27034-8

Ensure the Default C Shell Umask is Set Correctly

To ensure the default umask for users of the C shell is set properly, add or correct the `umask` setting in `/etc/csh.cshrc` to read as follows:

    umask

CCE-26669-2

Ensure the Default Umask is Set Correctly in /etc/profile

To ensure the default umask controlled by `/etc/profile` is set properly, add or correct the `umask` setting in `/etc/profile` to read as follows:

    umask

CCE-26981-1

Ensure that User Home Directories are not Group-Writable or World-Readable

For each human user of the system, view the permissions of the user's home directory:

    $ sudo ls -ld /home/USER

Ensure that the directory is not group-writable and that it is not world-readable. If necessary, repair the permissions:

    $ sudo chmod g-w /home/USER
    $ sudo chmod o-rwx /home/USER

CCE-27333-4 | Set Interactive Session Timeout | Terminating an idle 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 left unattended.

CCE-27457-1

Limit the Number of Concurrent Login Sessions Allowed Per User

Limiting the number of allowed users and sessions per user can limit risks related to Denial of Service attacks. This addresses concurrent sessions for a single account and does not address concurrent sessions by a single user via multiple accounts. The DoD requirement is 10. To set the number of concurrent sessions per user add the following line in `/etc/security/limits.conf`:

    * hard maxlogins

CCE-27195-7

Enable GUI Warning Banner

To enable displaying a login warning banner in the GNOME Display Manager's login screen, run the following command:

    $ sudo gconftool-2 --direct \
      --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
      --type bool \
      --set /apps/gdm/simple-greeter/banner_message_enable true

To display a banner, this setting must be enabled and then banner text must also be set.

CCE-27017-3

Set GUI Warning Banner Text

To set the text shown by the GNOME Display Manager in the login screen, run the following command:

    $ sudo gconftool-2 --direct \
      --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
      --type string \
      --set /apps/gdm/simple-greeter/banner_message_text \
      "Text of the warning banner here"

When entering a warning banner that spans several lines, remember to begin and end the string with `"`. This command writes directly either to the `/etc/gconf/gconf.xml.mandatory/%gconf-tree.xml` if it exists or to the file `/etc/gconf/gconf.xml.mandatory/apps/gdm/simple-greeter/%gconf.xml`. Either of these files can later be edited directly if necessary.

CCE-26974-6

Modify the System Login Banner

To configure the system login banner:
Edit `/etc/issue`. Replace the default text with a message compliant with the local site policy or a legal disclaimer. The DoD required text is either:
`You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions:
-The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations.
-At any time, the USG may inspect and seize data stored on this IS.
-Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose.
-This IS includes security measures (e.g., authentication and access controls) to protect USG interests -- not for your personal benefit or privacy.
-Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details.`
OR:
`Use of this or any other DoD interest computer system constitutes consent to monitoring at all times.
This is a DoD interest computer system. All DoD interest computer systems and related equipment are intended for the communication, transmission, processing, and storage of official U.S. Government or other authorized information only. All DoD interest computer systems are subject to monitoring at all times to ensure proper functioning of equipment and systems including security devices and systems, to prevent unauthorized use and violations of statutes and security regulations, to deter criminal activity, and for other similar purposes. Any user of a DoD interest computer system should be aware that any information placed in the system is subject to monitoring and is not subject to any expectation of privacy.
If monitoring of this or any other DoD interest computer system reveals possible evidence of violation of criminal statutes, this evidence and any other related information, including identification information about the user, may be provided to law enforcement officials. If monitoring of this or any other DoD interest computer systems reveals violations of security regulations or unauthorized use, employees who violate security regulations or make unauthorized use of DoD interest computer systems are subject to appropriate disciplinary action.
Use of this or any other DoD interest computer system constitutes consent to monitoring at all times.`
OR:
`I've read & consent to terms in IS user agreem't.`

CCE-27228-6

Set Password Hashing Algorithm in /etc/login.defs

In `/etc/login.defs`, add or correct the following line to ensure the system will use SHA-512 as the hashing algorithm:

    ENCRYPT_METHOD SHA512

CCE-26303-8

Set Password Hashing Algorithm in /etc/pam.d/system-auth

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.

CCE-27229-4

Set Password Hashing Algorithm in /etc/libuser.conf

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

CCE-27110-6

Set Lockout Time For Failed Password Attempts

To configure the system to lock out accounts after a number of incorrect login attempts and require an administrator to unlock the account using `pam_faillock.so`, modify the content of both `/etc/pam.d/system-auth` and `/etc/pam.d/password-auth` as follows:

- Add the following line immediately `before` the `pam_unix.so` statement in the `AUTH` section:

      auth required pam_faillock.so preauth silent deny= unlock_time= fail_interval=

- Add the following line immediately `after` the `pam_unix.so` statement in the `AUTH` section:

      auth [default=die] pam_faillock.so authfail deny= unlock_time= fail_interval=

- Add the following line immediately `before` the `pam_unix.so` statement in the `ACCOUNT` section:

      account required pam_faillock.so

CCE-26741-9

Limit Password Reuse

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. In the file `/etc/pam.d/system-auth`, append `remember=` to the line which refers to the `pam_unix.so` or `pam_pwhistory.so`module, as shown below:

- for the `pam_unix.so` case:

      password sufficient pam_unix.so existing_options remember=

- for the `pam_pwhistory.so` case:

      password requisite pam_pwhistory.so existing_options remember=

The DoD STIG requirement is 5 passwords.

CCE-27215-3

Set Interval For Counting Failed Password Attempts

Utilizing `pam_faillock.so`, the `fail_interval` directive configures the system to lock out accounts after a number of incorrect login attempts. Modify the content of both `/etc/pam.d/system-auth` and `/etc/pam.d/password-auth` as follows:

- Add the following line immediately `before` the `pam_unix.so` statement in the `AUTH` section:

      auth required pam_faillock.so preauth silent deny= unlock_time= fail_interval=

- Add the following line immediately `after` the `pam_unix.so` statement in the `AUTH` section:

      auth [default=die] pam_faillock.so authfail deny= unlock_time= fail_interval=

- Add the following line immediately `before` the `pam_unix.so` statement in the `ACCOUNT` section:

      account required pam_faillock.so

CCE-26844-1

Set Deny For Failed Password Attempts

To configure the system to lock out accounts after a number of incorrect login attempts using `pam_faillock.so`, modify the content of both `/etc/pam.d/system-auth` and `/etc/pam.d/password-auth` as follows:

- Add the following line immediately `before` the `pam_unix.so` statement in the `AUTH` section:

      auth required pam_faillock.so preauth silent deny= unlock_time= fail_interval=

- Add the following line immediately `after` the `pam_unix.so` statement in the `AUTH` section:

      auth [default=die] pam_faillock.so authfail deny= unlock_time= fail_interval=

- Add the following line immediately `before` the `pam_unix.so` statement in the `ACCOUNT` section:

      account required pam_faillock.so

CCE-26615-5 | Set Password Minimum Length | The pam_cracklib module's `minlen` parameter controls requirements for minimum characters required in a password. Add `minlen=` after pam_pwquality to set minimum password length requirements.

CCE-27227-8

Set Password to Maximum of Three Consecutive Repeating Characters

The pam_cracklib module's `maxrepeat` parameter controls requirements for consecutive repeating characters. When set to a positive number, it will reject passwords which contain more than that number of consecutive characters. Add `maxrepeat=` after pam_cracklib.so to prevent a run of ( + 1) or more identical characters:

    password required pam_cracklib.so maxrepeat=

CCE-26374-9

Set Password Strength Minimum Digit Characters

The pam_cracklib 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_cracklib will grant +1 additional length credit for each digit. Add `dcredit=-1` after pam_cracklib.so to require use of a digit in passwords.

CCE-27115-5

Set Password Strength Minimum Different Categories

The pam_cracklib module's `minclass` parameter controls requirements for usage of different character classes, or types, of character that must exist in a password before it is considered valid. For example, setting this value to three (3) requires that any password must have characters from at least three different categories in order to be approved. The default value is zero (0), meaning there are no required classes. There are four categories available:

    * Upper-case characters
    * Lower-case characters
    * Digits
    * Special characters (for example, punctuation)

Add `minclass=` after pam_cracklib.so entry into the `/etc/pam.d/system-auth` file in order to require differing categories of characters when changing passwords. For example to require at least three character classes to be used in password, use `minclass=3`.

CCE-26615-5 | Set Password Strength Minimum Different Characters | The pam_cracklib module's `difok` parameter controls requirements for usage of different characters during a password change. Add `difok=` after pam_cracklib.so to require differing characters when changing passwords. The DoD requirement is `4`.

CCE-26409-3

Set Password Strength Minimum Special Characters

The pam_cracklib 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_cracklib will grant +1 additional length credit for each special character. Add `ocredit=` after pam_cracklib.so to require use of a special character in passwords.

CCE-26631-2

Set Password Strength Minimum Lowercase Characters

The pam_cracklib 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_cracklib will grant +1 additional length credit for each lowercase character. Add `lcredit=-1` after pam_cracklib.so to require use of a lowercase character in passwords.

CCE-26601-5

Set Password Strength Minimum Uppercase Characters

The pam_cracklib 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_cracklib will grant +1 additional length credit for each uppercase character. Add `ucredit=-1` after pam_cracklib.so to require use of an upper case character in passwords.

CCE-27123-9 | Set Password Retry Prompts Permitted Per-Session | To configure the number of retry prompts that are permitted per-session: Edit the `pam_cracklib.so` statement in `/etc/pam.d/system-auth` to show `retry=`, or a lower value if site policy is more restrictive. The DoD requirement is a maximum of 3 prompts per session.

CCE-27291-4

Set Last Login/Access Notification

To configure the system to notify users of last login/access using `pam_lastlog`, add the following line immediately after `session required pam_limits.so`:

    session       required     pam_lastlog.so showfailed

Ensure Solid State Drives Do Not Contribute To Random-Number Entropy Pool

For each solid-state drive on the system, run:

     # echo 0 > /sys/block/DRIVE/queue/add_random

CCE-26992-8

Verify Permissions on shadow File

To properly set the permissions of `/etc/shadow`, run the command:

    $ sudo chmod 0000 /etc/shadow

CCE-26967-0

Verify Group Who Owns shadow File

To properly set the group owner of `/etc/shadow`, run the command:

    $ sudo chgrp root /etc/shadow

CCE-26822-7

Verify User Who Owns group File

To properly set the owner of `/etc/group`, run the command:

    $ sudo chown root /etc/group

CCE-26954-8

Verify Permissions on group File

To properly set the permissions of `/etc/group`, run the command:

    $ sudo chmod 644 /etc/group

CCE-26953-0

Verify User Who Owns passwd File

To properly set the owner of `/etc/passwd`, run the command:

    $ sudo chown root /etc/passwd

CCE-26975-3

Verify Group Who Owns gshadow File

To properly set the group owner of `/etc/gshadow`, run the command:

    $ sudo chgrp root /etc/gshadow

CCE-26856-5

Verify Group Who Owns passwd File

To properly set the group owner of `/etc/passwd`, run the command:

    $ sudo chgrp root /etc/passwd

CCE-27026-4

Verify User Who Owns gshadow File

To properly set the owner of `/etc/gshadow`, run the command:

    $ sudo chown root /etc/gshadow

CCE-26930-8

Verify Group Who Owns group File

To properly set the group owner of `/etc/group`, run the command:

    $ sudo chgrp root /etc/group

CCE-26951-4

Verify Permissions on gshadow File

To properly set the permissions of `/etc/gshadow`, run the command:

    $ sudo chmod 0000 /etc/gshadow

CCE-26947-2

Verify User Who Owns shadow File

To properly set the owner of `/etc/shadow`, run the command:

    $ sudo chown root /etc/shadow

CCE-26868-0

Verify Permissions on passwd File

To properly set the permissions of `/etc/passwd`, run the command:

    $ sudo chmod 0644 /etc/passwd

CCE-27424-1

Verify that Shared Library Files Have Root Ownership

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

CCE-27289-8

Verify that System Executables Have Restrictive Permissions

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

CCE-27623-8

Verify that System Executables Have Root Ownership

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

CCE-27381-3

Verify that Shared Library Files Have Restrictive Permissions

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

CCE-26769-0 | Ensure All SGID Executables Are Authorized | The SGID (set group id) bit should be set only on files that were installed via authorized means. A straightforward means of identifying unauthorized SGID files is determine if any were not installed as part of an RPM package, which is cryptographically verified. Investigate the origin of any unpackaged SGID files.
CCE-26872-2 | Ensure All Files Are Owned by a Group | If any files are not owned by a group, then the cause of their lack of group-ownership should be investigated. Following this, the files should be deleted or assigned to an appropriate group.
CCE-26642-9 | Ensure All World-Writable Directories Are Owned by a System Account | All directories in local partitions which are world-writable should be owned by root or another system account. If any world-writable directories are not owned by a system account, this should be investigated. Following this, the files should be deleted or assigned to an appropriate group.
CCE-27032-2 | Ensure All Files Are Owned by a User | If any files are not owned by a user, then the cause of their lack of ownership should be investigated. Following this, the files should be deleted or assigned to an appropriate user.

CCE-26910-0

Ensure No World-Writable Files Exist

It is generally a good idea to remove global (other) write access to a file when it is discovered. However, check with documentation for specific applications before making changes. Also, monitor for recurring world-writable files, as these may be symptoms of a misconfigured application or user account. Finally, this applies to real files and not virtual files that are a part of pseudo file systems such as `sysfs` or `procfs`.

CCE-26840-9

Verify that All World-Writable Directories Have Sticky Bits Set

When the so-called 'sticky bit' is set on a directory, only the owner of a given file may remove that file from the directory. Without the sticky bit, any user with write access to a directory may remove any file in the directory. Setting the sticky bit prevents users from removing each other's files. In cases where there is no reason for a directory to be world-writable, a better solution is to remove that permission rather than to set the sticky bit. However, if a directory is used by a particular application, consult that application's documentation instead of blindly changing modes.
To set the sticky bit on a world-writable directory DIR, run the following command:

    $ sudo chmod +t DIR

CCE-26497-8 | Ensure All SUID Executables Are Authorized | The SUID (set user id) bit should be set only on files that were installed via authorized means. A straightforward means of identifying unauthorized SGID files is determine if any were not installed as part of an RPM package, which is cryptographically verified. Investigate the origin of any unpackaged SUID files.

CCE-27016-5

Disable Modprobe Loading of USB Storage Driver

To prevent USB storage devices from being used, configure the kernel module loading system to prevent automatic loading of the USB storage driver. To configure the system to prevent the `usb-storage` kernel module from being loaded, add the following line to a file in the directory `/etc/modprobe.d`:

    install usb-storage /bin/true

This will prevent the `modprobe` program from loading the `usb-storage` module, but will not prevent an administrator (or another program) from using the `insmod` program to load the module manually.

CCE-27011-6

Disable Kernel Support for USB via Bootloader Configuration

All USB support can be disabled by adding the `nousb` argument to the kernel's boot loader configuration. To do so, append "nousb" to the kernel line in `/etc/grub.conf` as shown:

    kernel /vmlinuz-VERSION ro vga=ext root=/dev/VolGroup00/LogVol00 rhgb quiet nousb

WARNING: Disabling all kernel support for USB will cause problems for systems with USB-based keyboards, mice, or printers. This configuration is infeasible for systems which require USB devices, which is common.

CCE-27131-2 | Assign Password to Prevent Changes to Boot Firmware Configuration | Assign a password to the system boot firmware (historically called BIOS on PC systems) to require a password for any configuration changes.
CCE-26923-3 | Disable Booting from USB Devices in Boot Firmware | Configure the system boot firmware (historically called BIOS on PC systems) to disallow booting from USB drives.

CCE-26976-1

Disable the Automounter

The `autofs` daemon mounts and unmounts filesystems, such as user home directories shared via NFS, on demand. In addition, autofs can be used to handle removable media, and the default configuration provides the cdrom device as `/misc/cd`. However, this method of providing access to removable media is not common, so autofs can almost always be disabled if NFS is not in use. Even if NFS is required, it may be possible to configure filesystem mounts statically by editing `/etc/fstab` rather than relying on the automounter.
The `autofs` service can be disabled with the following command:

    $ sudo chkconfig autofs off

CCE-26677-5

Disable Mounting of udf

To configure the system to prevent the `udf` kernel module from being loaded, add the following line to a file in the directory `/etc/modprobe.d`:

    install udf /bin/true

This effectively prevents usage of this uncommon filesystem.

CCE-26404-4

Disable Mounting of squashfs

To configure the system to prevent the `squashfs` kernel module from being loaded, add the following line to a file in the directory `/etc/modprobe.d`:

    install squashfs /bin/true

This effectively prevents usage of this uncommon filesystem.

CCE-26361-6

Disable Mounting of hfsplus

To configure the system to prevent the `hfsplus` kernel module from being loaded, add the following line to a file in the directory `/etc/modprobe.d`:

    install hfsplus /bin/true

This effectively prevents usage of this uncommon filesystem.

CCE-26670-0

Disable Mounting of jffs2

To configure the system to prevent the `jffs2` kernel module from being loaded, add the following line to a file in the directory `/etc/modprobe.d`:

    install jffs2 /bin/true

This effectively prevents usage of this uncommon filesystem.

CCE-26800-3

Disable Mounting of hfs

To configure the system to prevent the `hfs` kernel module from being loaded, add the following line to a file in the directory `/etc/modprobe.d`:

    install hfs /bin/true

This effectively prevents usage of this uncommon filesystem.

CCE-26340-0

Disable Mounting of cramfs

To configure the system to prevent the `cramfs` kernel module from being loaded, add the following line to a file in the directory `/etc/modprobe.d`:

    install cramfs /bin/true

This effectively prevents usage of this uncommon filesystem.

CCE-26544-7

Disable Mounting of freevxfs

To configure the system to prevent the `freevxfs` kernel module from being loaded, add the following line to a file in the directory `/etc/modprobe.d`:

    install freevxfs /bin/true

This effectively prevents usage of this uncommon filesystem.

CCE-26622-1 | Add noexec Option to /dev/shm | The `noexec` mount option can be used to prevent binaries from being executed out of `/dev/shm`. It can be dangerous to allow the execution of binaries from world-writable temporary storage directories such as `/dev/shm`. Add the `noexec` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/dev/shm`.
CCE-26486-1 | Add nosuid Option to /dev/shm | The `nosuid` mount option can be used to prevent execution of setuid programs in `/dev/shm`. The SUID and SGID permissions should not be required in these world-writable directories. Add the `nosuid` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/dev/shm`.
CCE-26499-4 | Add nodev Option to /tmp | The `nodev` mount option can be used to prevent device files from being created in `/tmp`. Legitimate character and block devices should not exist within temporary directories like `/tmp`. Add the `nodev` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/tmp`.
CCE-26720-3 | Add noexec Option to /tmp | The `noexec` mount option can be used to prevent binaries from being executed out of `/tmp`. Add the `noexec` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/tmp`.
CCE-26762-5 | Add nosuid Option to /tmp | The `nosuid` mount option can be used to prevent execution of setuid programs in `/tmp`. The SUID and SGID permissions should not be required in these world-writable directories. Add the `nosuid` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/tmp`.

CCE-27056-1

Add nosuid Option to Removable Media Partitions

The `nosuid` mount option prevents set-user-identifier (SUID) and set-group-identifier (SGID) permissions from taking effect. These permissions allow users to execute binaries with the same permissions as the owner and group of the file respectively. Users should not be allowed to introduce SUID and SGID files into the system via partitions mounted from removeable media. Add the `nosuid` option to the fourth column of `/etc/fstab` for the line which controls mounting of any removable media partitions.

CCE-27045-4

Add nodev Option to Non-Root Local Partitions

The `nodev` mount option prevents files from being interpreted as character or block devices. Legitimate character and block devices should exist only in the `/dev` directory on the root partition or within chroot jails built for system services. Add the `nodev` option to the fourth column of `/etc/fstab` for the line which controls mounting of any non-root local partitions.

CCE-26860-7

Add nodev Option to Removable Media Partitions

The `nodev` mount option prevents files from being interpreted as character or block devices. Legitimate character and block devices should exist only in the `/dev` directory on the root partition or within chroot jails built for system services. Add the `nodev` option to the fourth column of `/etc/fstab` for the line which controls mounting of any removable media partitions.

CCE-27196-5

Add noexec Option to Removable Media Partitions

The `noexec` mount option prevents the direct execution of binaries on the mounted filesystem. Preventing the direct execution of binaries from removable media (such as a USB key) provides a defense against malicious software that may be present on such untrusted media. Add the `noexec` option to the fourth column of `/etc/fstab` for the line which controls mounting of any removable media partitions.

CCE-26582-7

Bind Mount /var/tmp To /tmp

The `/var/tmp` directory is a world-writable directory. Bind-mount it to `/tmp` in order to consolidate temporary storage into one location protected by the same techniques as `/tmp`. To do so, edit `/etc/fstab` and add the following line:

    /tmp     /var/tmp     none     rw,nodev,noexec,nosuid,bind     0 0

See the `mount(8)` man page for further explanation of bind mounting.

CCE-26778-1 | Add nodev Option to /dev/shm | The `nodev` mount option can be used to prevent creation of device files in `/dev/shm`. Legitimate character and block devices should not exist within temporary directories like `/dev/shm`. Add the `nodev` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/dev/shm`.

CCE-27031-4

Set Daemon Umask

The file `/etc/init.d/functions` includes initialization parameters for most or all daemons started at boot time. The default umask of 022 prevents creation of group- or world-writable files. To set the default umask for daemons, edit the following line, inserting 022 or 027 for umask appropriately:

    umask

Setting the umask to too restrictive a setting can cause serious errors at runtime. Many daemons on the system already individually restrict themselves to a umask of 077 in their own init scripts.

CCE-27010-8

Install PAE Kernel on Supported 32-bit x86 Systems

Systems that are using the 64-bit x86 kernel package do not need to install the kernel-PAE package because the 64-bit x86 kernel already includes this support. However, if the system is 32-bit and also supports the PAE and NX features as determined in the previous section, the kernel-PAE package should be installed to enable XD or NX support:

    $ sudo yum install kernel-PAE

The installation process should also have configured the bootloader to load the new kernel at boot. Verify this at reboot and modify `/etc/grub.conf` if necessary.

CCE-27163-5 | Enable NX or XD Support in the BIOS | Reboot the system and enter the BIOS or Setup configuration menu. Navigate the BIOS configuration menu and make sure that the option is enabled. The setting may be located under a Security section. Look for Execute Disable (XD) on Intel-based systems and No Execute (NX) on AMD-based systems.

CCE-27044-7

Disable Core Dumps for SUID programs

To set the runtime status of the `fs.suid_dumpable` kernel parameter, run the following command:

    $ sudo sysctl -w fs.suid_dumpable=0

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    fs.suid_dumpable = 0

CCE-27033-0

Disable Core Dumps for All Users

To disable core dumps for all users, add the following line to `/etc/security/limits.conf`:

    *     hard   core    0

CCE-27007-4

Enable ExecShield

To set the runtime status of the `kernel.exec-shield` kernel parameter, run the following command:

    $ sudo sysctl -w kernel.exec-shield=1

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    kernel.exec-shield = 1

CCE-26999-3

Enable Randomized Layout of Virtual Address Space

To set the runtime status of the `kernel.randomize_va_space` kernel parameter, run the following command:

    $ sudo sysctl -w kernel.randomize_va_space=2

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    kernel.randomize_va_space = 2

CCE-27366-4

Restrict Access to Kernel Message Buffer

To set the runtime status of the `kernel.dmesg_restrict` kernel parameter, run the following command:

    $ sudo sysctl -w kernel.dmesg_restrict=1

If this is not the system's default value, add the following line to `/etc/sysctl.conf`:

    kernel.dmesg_restrict = 1

Configure auditd flush priority

The `auditd` service can be configured to synchronously write audit event data to disk. Add or correct the following line in `/etc/audit/auditd.conf` to ensure that audit event data is fully synchronized with the log files on the disk:

    flush =

CCE-26933-2

Configure auditd to use audispd's syslog plugin

To configure the `auditd` service to use the `syslog` plug-in of the `audispd` audit event multiplexor, set the `active` line in `/etc/audisp/plugins.d/syslog.conf` to `yes`. Restart the `auditd` service:

    $ sudo service auditd restart

CCE-80500-2

Configure auditd Disk Full Action when Disk Space Is Full

The `auditd` service can be configured to take an action when disk space is running low but prior to running out of space completely. Edit the file `/etc/audit/auditd.conf`. Add or modify the following line, substituting ACTION appropriately:

    disk_full_action = ACTION

Set this value to `single` to cause the system to switch to single-user mode for corrective action. Acceptable values also include `syslog`, `exec`, `single`, and `halt`. For certain systems, the need for availability outweighs the need to log all actions, and a different setting should be determined. Details regarding all possible values for ACTION are described in the `auditd.conf` man page.

CCE-27550-3

Configure auditd Max Log File Size

Determine the amount of audit data (in megabytes) which should be retained in each log file. Edit the file `/etc/audit/auditd.conf`. Add or modify the following line, substituting the correct value of for STOREMB:

    max_log_file = STOREMB

Set the value to `6` (MB) or higher for general-purpose systems. Larger values, of course, support retention of even more audit data.

CCE-80507-7

Configure auditd space_left on Low Disk Space

The `auditd` service can be configured to take an action when disk space is running low but prior to running out of space completely. Edit the file `/etc/audit/auditd.conf`. Add or modify the following line, substituting SIZE_in_MB appropriately:

    space_left = SIZE_in_MB

Set this value to the appropriate size in Megabytes cause the system to notify the user of an issue.

CCE-27241-9

Configure auditd mail_acct Action on Low Disk Space

The `auditd` service can be configured to send email to a designated account in certain situations. Add or correct the following line in `/etc/audit/auditd.conf` to ensure that administrators are notified via email for those situations:

    action_mail_acct =

CCE-27239-3

Configure auditd admin_space_left Action on Low Disk Space

The `auditd` service can be configured to take an action when disk space is running low but prior to running out of space completely. Edit the file `/etc/audit/auditd.conf`. Add or modify the following line, substituting ACTION appropriately:

    admin_space_left_action = ACTION

Set this value to `single` to cause the system to switch to single-user mode for corrective action. Acceptable values also include `suspend` and `halt`. For certain systems, the need for availability outweighs the need to log all actions, and a different setting should be determined. Details regarding all possible values for ACTION are described in the `auditd.conf` man page.

CCE-27238-5

Configure auditd space_left Action on Low Disk Space

The `auditd` service can be configured to take an action when disk space starts to run low. Edit the file `/etc/audit/auditd.conf`. Modify the following line, substituting ACTION appropriately:

    space_left_action = ACTION

Possible values for ACTION are described in the `auditd.conf` man page. These include:

- `ignore`
- `syslog`
- `email`
- `exec`
- `suspend`
- `single`
- `halt`

Set this to `email` (instead of the default, which is `suspend`) as it is more likely to get prompt attention. Acceptable values also include `suspend`, `single`, and `halt`.

CCE-80501-0

Configure auditd Disk Error Action on Disk Error

The `auditd` service can be configured to take an action when there is a disk error. Edit the file `/etc/audit/auditd.conf`. Add or modify the following line, substituting ACTION appropriately:

    disk_error_action = ACTION

Set this value to `single` to cause the system to switch to single-user mode for corrective action. Acceptable values also include `syslog`, `exec`, `single`, and `halt`. For certain systems, the need for availability outweighs the need to log all actions, and a different setting should be determined. Details regarding all possible values for ACTION are described in the `auditd.conf` man page.

CCE-27522-2

Configure auditd Number of Logs Retained

Determine how many log files `auditd` should retain when it rotates logs. Edit the file `/etc/audit/auditd.conf`. Add or modify the following line, substituting NUMLOGS with the correct value of :

    num_logs = NUMLOGS

Set the value to 5 for general-purpose systems. Note that values less than 2 result in no log rotation.

CCE-27237-7

Configure auditd max_log_file_action Upon Reaching Maximum Log Size

The default action to take when the logs reach their maximum size is to rotate the log files, discarding the oldest one. To configure the action taken by `auditd`, add or correct the line in `/etc/audit/auditd.conf`:

    max_log_file_action = ACTION

Possible values for ACTION are described in the `auditd.conf` man page. These include:

- `ignore`
- `syslog`
- `suspend`
- `rotate`
- `keep_logs`

Set the `ACTION` to `rotate` to ensure log rotation occurs. This is the default. The setting is case-insensitive.

CCE-27177-5

Record Events that Modify the System's Discretionary Access Controls - fchown

At a minimum the audit system should collect file permission changes for all users and root. Add the following to `/etc/audit/audit.rules`:

    -a always,exit -F arch=b32 -S fchown -F auid>=500 -F auid!=4294967295 -k perm_mod

If the system is 64 bit then also add the following:

    -a always,exit -F arch=b64 -S fchown -F auid>=500 -F auid!=4294967295 -k perm_mod

CCE-27185-8

Record Events that Modify the System's Discretionary Access Controls - setxattr

At a minimum the audit system should collect file permission changes for all users and root. Add the following to `/etc/audit/audit.rules`:

    -a always,exit -F arch=b32 -S setxattr -F auid>=500 -F auid!=4294967295 -k perm_mod

If the system is 64 bit then also add the following:

    -a always,exit -F arch=b64 -S setxattr -F auid>=500 -F auid!=4294967295 -k perm_mod

CCE-27173-4

Record Events that Modify the System's Discretionary Access Controls - chown

At a minimum the audit system should collect file permission changes for all users and root. Add the following to `/etc/audit/audit.rules`:

    -a always,exit -F arch=b32 -S chown -F auid>=500 -F auid!=4294967295 -k perm_mod

If the system is 64 bit then also add the following:

    -a always,exit -F arch=b64 -S chown -F auid>=500 -F auid!=4294967295 -k perm_mod

CCE-27183-3

Record Events that Modify the System's Discretionary Access Controls - lsetxattr

At a minimum the audit system should collect file permission changes for all users and root. Add the following to `/etc/audit/audit.rules`:

    -a always,exit -F arch=b32 -S lsetxattr -F auid>=500 -F auid!=4294967295 -k perm_mod

If the system is 64 bit then also add the following:

    -a always,exit -F arch=b64 -S lsetxattr -F auid>=500 -F auid!=4294967295 -k perm_mod

CCE-27181-7

Record Events that Modify the System's Discretionary Access Controls - lchown

At a minimum the audit system should collect file permission changes for all users and root. Add the following to `/etc/audit/audit.rules`:

    -a always,exit -F arch=b32 -S lchown -F auid>=500 -F auid!=4294967295 -k perm_mod

If the system is 64 bit then also add the following:

    -a always,exit -F arch=b64 -S lchown -F auid>=500 -F auid!=4294967295 -k perm_mod

CCE-26280-8

Record Events that Modify the System's Discretionary Access Controls - chmod

At a minimum the audit system should collect file permission changes for all users and root. Add the following to `/etc/audit/audit.rules`:

    -a always,exit -F arch=b32 -S chmod -F auid>=500 -F auid!=4294967295 -k perm_mod

If the system is 64 bit then also add the following:

    -a always,exit -F arch=b64 -S chmod  -F auid>=500 -F auid!=4294967295 -k perm_mod

CCE-27184-1

Record Events that Modify the System's Discretionary Access Controls - removexattr

At a minimum the audit system should collect file permission changes for all users and root. Add the following to `/etc/audit/audit.rules`:

    -a always,exit -F arch=b32 -S removexattr -F auid>=500 -F auid!=4294967295 -k perm_mod

If the system is 64 bit then also add the following:

    -a always,exit -F arch=b64 -S removexattr -F auid>=500 -F auid!=4294967295 -k perm_mod

CCE-27174-2

Record Events that Modify the System's Discretionary Access Controls - fchmod

At a minimum the audit system should collect file permission changes for all users and root. Add the following to `/etc/audit/audit.rules`:

    -a always,exit -F arch=b32 -S fchmod -F auid>=500 -F auid!=4294967295 -k perm_mod

If the system is 64 bit then also add the following:

    -a always,exit -F arch=b64 -S fchmod -F auid>=500 -F auid!=4294967295 -k perm_mod

CCE-27178-3

Record Events that Modify the System's Discretionary Access Controls - fchownat

At a minimum the audit system should collect file permission changes for all users and root. Add the following to `/etc/audit/audit.rules`:

    -a always,exit -F arch=b32 -S fchownat -F auid>=500 -F auid!=4294967295 -k perm_mod

If the system is 64 bit then also add the following:

    -a always,exit -F arch=b64 -S fchownat -F auid>=500 -F auid!=4294967295 -k perm_mod

CCE-27179-1

Record Events that Modify the System's Discretionary Access Controls - fremovexattr

At a minimum the audit system should collect file permission changes for all users and root. Add the following to `/etc/audit/audit.rules`:

    -a always,exit -F arch=b32 -S fremovexattr -F auid>=500 -F auid!=4294967295 -k perm_mod

If the system is 64 bit then also add the following:

    -a always,exit -F arch=b64 -S fremovexattr -F auid>=500 -F auid!=4294967295 -k perm_mod

CCE-27182-5

Record Events that Modify the System's Discretionary Access Controls - lremovexattr

At a minimum the audit system should collect file permission changes for all users and root. Add the following to `/etc/audit/audit.rules`:

    -a always,exit -F arch=b32 -S lremovexattr -F auid>=500 -F auid!=4294967295 -k perm_mod

If the system is 64 bit then also add the following:

    -a always,exit -F arch=b64 -S lremovexattr -F auid>=500 -F auid!=4294967295 -k perm_mod

CCE-27180-9

Record Events that Modify the System's Discretionary Access Controls - fsetxattr

At a minimum the audit system should collect file permission changes for all users and root. Add the following to `/etc/audit/audit.rules`:

    -a always,exit -F arch=b32 -S fsetxattr -F auid>=500 -F auid!=4294967295 -k perm_mod

If the system is 64 bit then also add the following:

    -a always,exit -F arch=b64 -S fsetxattr -F auid>=500 -F auid!=4294967295 -k perm_mod

CCE-27175-9

Record Events that Modify the System's Discretionary Access Controls - fchmodat

At a minimum the audit system should collect file permission changes for all users and root. Add the following to `/etc/audit/audit.rules`:

    -a always,exit -F arch=b32 -S fchmodat -F auid>=500 -F auid!=4294967295 -k perm_mod

If the system is 64 bit then also add the following:

    -a always,exit -F arch=b64 -S fchmodat -F auid>=500 -F auid!=4294967295 -k perm_mod

CCE-27169-2

Record Attempts to Alter Time Through stime

Add the following line to `/etc/audit/audit.rules` for both 32-bit and 64-bit systems:

    # audit_time_rules
    -a always,exit -F arch=b32 -S stime -k audit_time_rules

Since the 64-bit version of the "stime" system call is not defined in the audit lookup table, the corresponding "-F arch=b64" form of this rule is not expected to be defined on 64-bit systems (the aforementioned "-F arch=b32" stime rule form itself is sufficient for both 32-bit and 64-bit systems). The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport. Multiple system calls can be defined on the same line to save space if desired, but is not required. See an example of multiple combined syscalls:

    -a always,exit -F arch=b64 -S adjtimex -S settimeofday -k audit_time_rules

CCE-27203-9

Record attempts to alter time through settimeofday

On a 32-bit system, add the following to `/etc/audit/audit.rules`:

    # audit_time_rules
    -a always,exit -F arch=b32 -S settimeofday -k audit_time_rules

On a 64-bit system, add the following to `/etc/audit/audit.rules`:

    # audit_time_rules
    -a always,exit -F arch=b64 -S settimeofday -k audit_time_rules

The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport. Multiple system calls can be defined on the same line to save space if desired, but is not required. See an example of multiple combined syscalls:

    -a always,exit -F arch=b64 -S adjtimex -S settimeofday -k audit_time_rules

CCE-27172-6

Record Attempts to Alter the localtime File

Add the following to `/etc/audit/audit.rules`:

    -w /etc/localtime -p wa -k audit_time_rules

The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport and should always be used.

CCE-27170-0

Record Attempts to Alter Time Through clock_settime

On a 32-bit system, add the following to `/etc/audit/audit.rules`:

    # time-change
    -a always,exit -F arch=b32 -S clock_settime -F a0=0x0 -F key=time-change

On a 64-bit system, add the following to `/etc/audit/audit.rules`:

    # time-change
    -a always,exit -F arch=b64 -S clock_settime -F a0=0x0 -F key=time-change

The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport. Multiple system calls can be defined on the same line to save space if desired, but is not required. See an example of multiple combined syscalls:

    -a always,exit -F arch=b64 -S adjtimex -S settimeofday -k audit_time_rules

CCE-26242-8

Record attempts to alter time through adjtimex

On a 32-bit system, add the following to `/etc/audit/audit.rules`:

    # audit_time_rules
    -a always,exit -F arch=b32 -S adjtimex -k audit_time_rules

On a 64-bit system, add the following to `/etc/audit/audit.rules`:

    # audit_time_rules
    -a always,exit -F arch=b64 -S adjtimex -k audit_time_rules

The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport. Multiple system calls can be defined on the same line to save space if desired, but is not required. See an example of multiple combined syscalls:

    -a always,exit -F arch=b64 -S adjtimex -S settimeofday -k audit_time_rules

CCE-26611-4

Ensure auditd Collects Information on Kernel Module Loading and Unloading

Add the following to `/etc/audit/audit.rules` in order to capture kernel module loading and unloading events, setting ARCH to either b32 or b64 as appropriate for your system:

    -w /sbin/insmod -p x -k modules
    -w /sbin/rmmod -p x -k modules
    -w /sbin/modprobe -p x -k modules
    -a always,exit -F arch=ARCH -S init_module -S delete_module -k modules

CCE-26457-2

Ensure auditd Collects Information on the Use of Privileged Commands

At a minimum the audit system should collect the execution of privileged commands for all users and root. To find the relevant setuid / setgid programs, run the following command for each local partition PART:

    $ sudo find PART -xdev -type f -perm -4000 -o -type f -perm -2000 2>/dev/null

Then, for each setuid / setgid program on the system, add a line of the following form to `/etc/audit/audit.rules`, where SETUID_PROG_PATH is the full path to each setuid / setgid program in the list:

    -a always,exit -F path=SETUID_PROG_PATH -F perm=x -F auid>=500 -F auid!=4294967295 -k privileged

CCE-26691-6

Record Attempts to Alter Login and Logout Events

The audit system already collects login info for all users and root. To watch for attempted manual edits of files involved in storing login events, add the following to `/etc/audit/audit.rules`:

    -w /var/log/tallylog -p wa -k logins
    -w /var/run/faillock/ -p wa -k logins
    -w /var/log/lastlog -p wa -k logins

CCE-26662-7

Ensure auditd Collects System Administrator Actions

At a minimum the audit system should collect administrator actions for all users and root. Add the following to `/etc/audit/audit.rules`:

    -w /etc/sudoers -p wa -k actions

CCE-26648-6

Record Events that Modify the System's Network Environment

Add the following to `/etc/audit/audit.rules`, setting ARCH to either b32 or b64 as appropriate for your system:

    # audit_rules_networkconfig_modification
    -a always,exit -F arch=ARCH -S sethostname -S setdomainname -k audit_rules_networkconfig_modification
    -w /etc/issue -p wa -k audit_rules_networkconfig_modification
    -w /etc/issue.net -p wa -k audit_rules_networkconfig_modification
    -w /etc/hosts -p wa -k audit_rules_networkconfig_modification
    -w /etc/sysconfig/network -p wa -k audit_rules_networkconfig_modification

CCE-26664-3

Record Events that Modify User/Group Information

Add the following to `/etc/audit/audit.rules`, in order to capture events that modify account changes:

    # audit_rules_usergroup_modification
    -w /etc/group -p wa -k audit_rules_usergroup_modification
    -w /etc/passwd -p wa -k audit_rules_usergroup_modification
    -w /etc/gshadow -p wa -k audit_rules_usergroup_modification
    -w /etc/shadow -p wa -k audit_rules_usergroup_modification
    -w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification

CCE-80502-8

System Audit Logs Must Have Mode 0750 or Less Permissive

If `log_group` in `/etc/audit/auditd.conf` is set to a group other than the `root` group account, change the mode of the audit log files with the following command:

    $ sudo chmod 0750 /var/log/audit

Otherwise, change the mode of the audit log files with the following command:

    $ sudo chmod 0700 /var/log/audit

CCE-26610-6

Record Attempts to Alter Process and Session Initiation Information

The audit system already collects process information for all users and root. To watch for attempted manual edits of files involved in storing such process information, add the following to `/etc/audit/audit.rules`:

    -w /var/run/utmp -p wa -k session
    -w /var/log/btmp -p wa -k session
    -w /var/log/wtmp -p wa -k session

CCE-26712-0

Ensure auditd Collects Unauthorized Access Attempts to Files (unsuccessful)

At a minimum the audit system should collect unauthorized file accesses for all users and root. Add the following to `/etc/audit/audit.rules`:

    -a always,exit -F arch=b32 -S creat -S open -S openat -S open_by_handle_at -S truncate -S ftruncate -F exit=-EACCES -F auid>=500 -F auid!=4294967295 -k access
    -a always,exit -F arch=b32 -S creat -S open -S openat -S open_by_handle_at -S truncate -S ftruncate -F exit=-EPERM -F auid>=500 -F auid!=4294967295 -k access

If the system is 64 bit then also add the following:

    -a always,exit -F arch=b64 -S creat -S open -S openat -S open_by_handle_at -S truncate -S ftruncate -F exit=-EACCES -F auid>=500 -F auid!=4294967295 -k access
    -a always,exit -F arch=b64 -S creat -S open -S openat -S open_by_handle_at -S truncate -S ftruncate -F exit=-EPERM -F auid>=500 -F auid!=4294967295 -k access

CCE-26651-0

Ensure auditd Collects File Deletion Events by User

At a minimum the audit system should collect file deletion events for all users and root. Add the following to `/etc/audit/audit.rules`, setting ARCH to either b32 or b64 as appropriate for your system:

    -a always,exit -F arch=ARCH -S rmdir -S unlink -S unlinkat -S rename -S renameat -F auid>=500 -F auid!=4294967295 -k delete

CCE-26573-6

Ensure auditd Collects Information on Exporting to Media (successful)

At a minimum the audit system should collect media exportation events for all users and root. Add the following to `/etc/audit/audit.rules`, setting ARCH to either b32 or b64 as appropriate for your system:

    -a always,exit -F arch=ARCH -S mount -F auid>=500 -F auid!=4294967295 -k export

CCE-26612-2

Make the auditd Configuration Immutable

Add the following to `/etc/audit/audit.rules` in order to make the configuration immutable:

    -e 2

With this setting, a reboot will be required to change any audit rules.

CCE-27244-3

System Audit Logs Must Be Owned By Root

To properly set the owner of `/var/log`, run the command:

    $ sudo chown root /var/log

CCE-27243-5

System Audit Logs Must Have Mode 0640 or Less Permissive

If `log_group` in `/etc/audit/auditd.conf` is set to a group other than the `root` group account, change the mode of the audit log files with the following command:

    $ sudo chmod 0640 audit_file

Otherwise, change the mode of the audit log files with the following command:

    $ sudo chmod 0600 audit_file

CCE-26657-7

Record Events that Modify the System's Mandatory Access Controls

Add the following to `/etc/audit/audit.rules`:

    -w /etc/selinux/ -p wa -k MAC-policy

CCE-26785-6

Enable Auditing for Processes Which Start Prior to the Audit Daemon

To ensure all processes can be audited, even those which start prior to the audit daemon, add the argument `audit=1` to the kernel line in `/etc/grub.conf`, in the manner below:

    kernel /vmlinuz-version ro vga=ext root=/dev/VolGroup00/LogVol00 rhgb quiet audit=1

CCE-27058-7

Enable auditd Service

The `auditd` service is an essential userspace component of the Linux Auditing System, as it is responsible for writing audit records to disk. The `auditd` service can be enabled with the following command:

    $ sudo chkconfig --level 2345 auditd on

CCE-80506-9

Ensure Users Re-Authenticate for Privilege Escalation - sudo

The sudo `NOPASSWD` and `!authenticate` option, when specified, allows a user to execute commands using sudo without having to authenticate. This should be disabled by making sure that `NOPASSWD` and/or `!authenticate` do not exist in `/etc/sudoers` configuration file or any sudo configuration snippets in `/etc/sudoers.d/`.

CCE-RHEL6-CCE-TBD

Install the dracut-fips Package

To enable FIPS, the system requires that the `dracut-fips` package be installed. The `dracut-fips` package can be installed with the following command:

    $ sudo yum install dracut-fips

CCE-RHEL6-CCE-TBD

Enable FIPS Mode in GRUB

To ensure FIPS mode is enabled, rebuild `initramfs` by running the following command:

    dracut -f

After the `dracut` command has been run, add the argument `fips=1` to the default GRUB kernel line for the Linux operating system in `/etc/grub.conf`, in the manner below:

    kernel /vmlinuz-version ro vga=ext root=/dev/VolGroup00/LogVol00 rhgb quiet fips=1

CCE-RHEL6-CCE-TBD | The Installed Operating System Is Vendor Supported and Certified | The installed operating system must be maintained and certified by a vendor. Red Hat Enterprise Linux is supported by Red Hat, Inc. As the Red Hat Enterprise Linux vendor, Red Hat, Inc. is responsible for providing security patches as well as meeting and maintaining goverment certifications and standards.

CCE-26731-0

Verify and Correct File Permissions with RPM

The RPM package management system can check file access permissions of installed software packages, including many that are important to system security. After locating a file with incorrect permissions which can be found with

    $ rpm -Va | grep '^.M'

, run the following command to determine which package owns it:

    $ rpm -qf FILENAME

Next, run the following command to reset its permissions to the correct values:

    $ sudo rpm --setperms PACKAGENAME

CCE-80499-7

Verify and Correct Ownership with RPM

The RPM package management system can check file ownership permissions of installed software packages, including many that are important to system security. After locating a file with incorrect permissions, which can be found with

    rpm -Va | grep "^.....\(U\|.G\)"

run the following command to determine which package owns it:

    $ rpm -qf FILENAME

Next, run the following command to reset its permissions to the correct values:

    $ sudo rpm --setugids PACKAGENAME

CCE-27223-7

Verify File Hashes with RPM

The RPM package management system can check the hashes of installed software packages, including many that are important to system security. Run the following command to list which files on the system have hashes that differ from what is expected by the RPM database:

    $ rpm -Va | grep '^..5'

A "c" in the second column indicates that a file is a configuration file, which may appropriately be expected to change. If the file was not expected to change, investigate the cause of the change using audit logs or other means. The package can then be reinstalled to restore the file. Run the following command to determine which package owns the file:

    $ rpm -qf FILENAME

The package can be reinstalled from a yum repository using the command:

    $ sudo yum reinstall PACKAGENAME

Alternatively, the package can be reinstalled from trusted media using the command:

    $ sudo rpm -Uvh PACKAGENAME

CCE-80511-9 | Configure Backups of User Data | The operating system must conduct backups of user data contained in the operating system. The operating system provides utilities for automating backups of user data. Commercial and open-source products are also available.

CCE-27529-7

Install Virus Scanning Software

Install virus scanning software, which uses signatures to search for the presence of viruses on the filesystem. The McAfee VirusScan Enterprise for Linux virus scanning tool is provided for DoD systems. Ensure virus definition files are no older than 7 days, or their last release. Configure the virus scanning software to perform scans dynamically on all accessed files. If this is not possible, configure the system to scan all altered files on the system on a daily basis. If the system processes inbound SMTP mail, configure the virus scanner to scan all received mail.

CCE-27409-2

Install Intrusion Detection Software

The base Red Hat platform already includes a sophisticated auditing system that can detect intruder activity, as well as SELinux, which provides host-based intrusion prevention capabilities by confining privileged programs and user sessions which may become compromised.
In DoD environments, supplemental intrusion detection tools, such as, the McAfee Host-based Security System, are available to integrate with existing infrastructure. When these supplemental tools interfere with the proper functioning of SELinux, SELinux takes precedence.

CCE-27024-9

Install AIDE

Install the AIDE package with the command:

    $ sudo yum install aide

CCE-27222-9

Configure Periodic Execution of AIDE

To implement a daily execution of AIDE at 4:05am using cron, add the following line to `/etc/crontab`:

    05 4 * * * root /usr/sbin/aide --check

AIDE can be executed periodically through other means; this is merely one example.

CCE-27135-3

Build and Test AIDE Database

Run the following command to generate a new database:

    $ sudo /usr/sbin/aide --init

By default, the database will be written to the file `/var/lib/aide/aide.db.new.gz`. Storing the database, the configuration file `/etc/aide.conf`, and the binary `/usr/sbin/aide` (or hashes of these files), in a secure location (such as on read-only media) provides additional assurance about their integrity. The newly-generated database can be installed as follows:

    $ sudo cp /var/lib/aide/aide.db.new.gz /var/lib/aide/aide.db.gz

To initiate a manual check, run the following command:

    $ sudo /usr/sbin/aide --check

If this check produces any unexpected output, investigate.

CCE-27221-1

Disable Prelinking

The prelinking feature changes binaries in an attempt to decrease their startup time. In order to disable it, change or add the following line inside the file `/etc/sysconfig/prelink`:

    PRELINKING=no

Next, run the following command to return binaries to a normal, non-prelinked state:

    $ sudo /usr/sbin/prelink -ua

CCE-26638-7

Implement Blank Screensaver

Run the following command to set the screensaver mode in the GNOME desktop to a blank screen:

    $ sudo gconftool-2 --direct \
      --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
      --type string \
      --set /apps/gnome-screensaver/mode blank-only

CCE-26235-2

Enable Screen Lock Activation After Idle Period

Run the following command to activate locking of the screensaver in the GNOME desktop when it is activated:

    $ sudo gconftool-2 --direct \
      --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
      --type bool \
      --set /apps/gnome-screensaver/lock_enabled true

CCE-26600-7

GNOME Desktop Screensaver Mandatory Use

Run the following command to activate the screensaver in the GNOME desktop after a period of inactivity:

    $ sudo gconftool-2 --direct \
      --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
      --type bool \
      --set /apps/gnome-screensaver/idle_activation_enabled true

CCE-80503-6

Set GNOME Screen Locking Keybindings

Run the following command to prevent changes to the screensaver lock keybindings:

    $ sudo gconftool-2 --direct \
      --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
      --type string \
      --set /apps/gnome_settings_daemon/keybindings/screensaver "<Control><Alt>l"

Set GNOME Login Maximum Allowed Inactivity

Run the following command to set the maximum allowed period of inactivity for an inactive user in the GNOME desktop to minutes:

    $ sudo gconftool-2 \
      --direct \
      --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
      --type int \
      --set /desktop/gnome/session/max_idle_time

Set GNOME Login Maximum Allowed Inactivity Action

Run the following command to set force logout an inactive user when the maximum allowed inactivity period has expired:

    $ sudo gconftool-2 --direct \
      --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
      --type string \
      --set /desktop/gnome/session/max_idle_action "forced-logout"

CCE-26828-4

Set GNOME Login Inactivity Timeout

Run the following command to set the idle time-out value for inactivity in the GNOME desktop to minutes:

    $ sudo gconftool-2 \
      --direct \
      --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
      --type int \
      --set /desktop/gnome/session/idle_delay

CCE-27035-5

Disable GNOME Automounting

The system's default desktop environment, GNOME, will mount devices and removable media (such as DVDs, CDs and USB flash drives) whenever they are inserted into the system. Disable automount and autorun within GNOME by running the following:

    $ sudo gconftool-2 --direct \
      --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
      --type bool \
      --set /apps/nautilus/preferences/media_automount false
    $ sudo gconftool-2 --direct \
      --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
      --type bool \
      --set /apps/nautilus/preferences/media_autorun_never true

CCE-27224-5

Disable All GNOME Thumbnailers

The system's default desktop environment, GNOME, uses a number of different thumbnailer programs to generate thumbnails for any new or modified content in an opened folder. The following command can disable the execution of these thumbnail applications:

    $ sudo gconftool-2 --direct \
      --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
      --type bool \
      --set /desktop/gnome/thumbnailers/disable_all true

This effectively prevents an attacker from gaining access to a system through a flaw in GNOME's Nautilus thumbnail creators.

Disable the GNOME Clock Temperature Feature

Run the following command to activate locking of the screensaver in the GNOME desktop when it is activated:

    $ sudo gconftool-2 --direct \
      --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
      --type bool \
      --set /apps/panel/applets/clock/prefs/show_temperature false

Disable the GNOME Clock Weather Feature

Run the following command to activate locking of the screensaver in the GNOME desktop when it is activated:

    $ sudo gconftool-2 --direct \
      --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
      --type bool \
      --set /apps/panel/applets/clock/prefs/show_weather false

Disable Ctrl-Alt-Del Reboot Key Sequence in GNOME

By default, `GNOME` will reboot the system if the `Ctrl-Alt-Del` key sequence is pressed.
To configure the system to ignore the `Ctrl-Alt-Del` key sequence from the Graphical User Interface (GUI) instead of rebooting the system, run the following:

    $ sudo gconftool-2 --direct \
      --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
      --type string \
      --set /apps/gnome_settings_daemon/keybindings/power ""

Disable GDM Guest Login

The GNOME Display Manager (GDM) can allow users to login without credentials which can be useful for public kiosk scenarios. Allowing users to login without credentials or "guest" account access has inherent security risks and should be disabled. To do disable timed logins or guest account access, set the `TimedLoginEnable` to `false` in the `[daemon]` section in `/etc/gdm/custom.conf`. For example:

    [daemon]
    TimedLoginEnable=false

Disable the GNOME Login Restart and Shutdown Buttons

In the default graphical environment, users logging directly into the system are greeted with a login screen that allows any user, known or unknown, the ability shutdown or restart the system. This functionality should be disabled by running the following:

    $ sudo gconftool-2 --direct \
      --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
      --type bool \
      --set /apps/gdm/simple-greeter/disable_restart_buttons true

Disable GDM Automatic Login

The GNOME Display Manager (GDM) can allow users to automatically login without user interaction or credentials. User should always be required to authenticate themselves to the system that they are authorized to use. To disable user ability to automatically login to the system, set the `AutomaticLoginEnable` to `false` in the `[daemon]` section in `/etc/gdm/custom.conf`. For example:

    [daemon]
    AutomaticLoginEnable=false

CCE-27230-2

Disable the User List

In the default graphical environment, users logging directly into the system are greeted with a login screen that displays all known users. This functionality should be disabled.
Run the following command to disable the user list:

    $ sudo gconftool-2 --direct \
      --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
      --type bool \
      --set /apps/gdm/simple-greeter/disable_user_list true

Disable WIFI Network Connection Creation in GNOME

`GNOME` allows users to create ad-hoc wireless connections through the `NetworkManager` applet. Wireless connections should be disabled by running the following:

    $ sudo gconftool-2 --direct \
      --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
      --type bool \
      --set /apps/nm-applet/disable-wifi-create true

Disable WIFI Network Connection Notification in GNOME

By default, `GNOME` disables WIFI notification when connecting to a wireless network. This should be permanently set so that users do not connect to a wireless network when the system finds one. While useful for mobile devices, this setting should be disabled for all other systems. To configure the system to disable the WIFI notication, run the following:

    $ sudo gconftool-2 --direct \
      --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
      --type bool \
      --set /apps/nm-applet/disable-connected-notifications true

Disable WIFI Network Disconnect Notification in GNOME

By default, `GNOME` disables WIFI notification when disconnecting from a wireless network. This should be permanently set so that users do not connect to a wireless network when the system finds one. While useful for mobile devices, this setting should be disabled for all other systems. To configure the system to disable the WIFI notication, run the following:

    $ sudo gconftool-2 --direct \
      --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
      --type bool \
      --set /apps/nm-applet/disable-disconnected-notifications true

CCE-26709-6

Ensure gpgcheck Enabled In Main Yum Configuration

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

CCE-27635-2

Ensure Software Patches Installed

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`.

CCE-26506-6

Ensure Red Hat GPG Key Installed

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

CCE-26647-8

Ensure gpgcheck Enabled For All Yum Package Repositories

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

CCE-27596-6

Encrypt Partitions

Red Hat Enterprise Linux 6 natively supports partition encryption through the Linux Unified Key Setup-on-disk-format (LUKS) technology. The easiest way to encrypt a partition is during installation time.
For manual installations, select the `Encrypt` checkbox during partition creation to encrypt the partition. When this option is selected the system will prompt for a passphrase to use in decrypting the partition. The passphrase will subsequently need to be entered manually every time the system boots.
For automated/unattended installations, it is possible to use Kickstart by adding the `--encrypted` and `--passphrase=` options to the definition of each partition to be encrypted. For example, the following line would encrypt the root partition:

    part / --fstype=ext3 --size=100 --onpart=hda1 --encrypted --passphrase=PASSPHRASE

Any PASSPHRASE is stored in the Kickstart in plaintext, and the Kickstart must then be protected accordingly. Omitting the `--passphrase=` option from the partition definition will cause the installer to pause and interactively ask for the passphrase during installation.
By default, the `Anaconda` installer uses `aes-xts-plain64` cipher with a minimum `512` bit key size which should be compatible with FIPS enabled.
Detailed information on encrypting partitions using LUKS or LUKS ciphers can be found on the Red Hat Documentation web site:
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Security_Guide/chap-Security_Guide-Encryption.html#sect-Security_Guide-LUKS_Disk_Encryption

CCE-26557-9 | Ensure /home Located On Separate Partition | If user home directories will be stored locally, create a separate partition for `/home` at installation time (or migrate it later using LVM). If `/home` will be mounted from another system such as an NFS server, then creating a separate partition is not necessary at installation time, and the mountpoint can instead be configured later.
CCE-26435-8 | Ensure /tmp Located On Separate Partition | 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.
CCE-26639-5 | Ensure /var Located On Separate Partition | 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.
CCE-26436-6 | Ensure /var/log/audit Located On Separate Partition | Audit logs are stored in the `/var/log/audit` directory. Ensure that it has its own partition or logical volume at installation time, or migrate it later using LVM. Make absolutely certain that it is large enough to store all audit logs that will be created by the auditing daemon.
CCE-26215-4 | Ensure /var/log Located On Separate Partition | System logs are stored in the `/var/log` directory. Ensure that it has its own partition or logical volume at installation time, or migrate it using LVM.