Vulnerability Discussion

Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one.

Audit records can be generated from various components within the information system (e.g., module or policy filter).

The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records.

DoD has defined the list of events for which RHEL 8 will provide an audit record generation capability as the following:

1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels);

2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system;

3) All account creations, modifications, disabling, and terminations; and

4) All kernel module load, unload, and restart actions.

From "Pam_Faillock man" pages: Note the default directory that pam_faillock uses is usually cleared on system boot so the access will be reenabled after system reboot. If that is undesirable a different tally directory must be set with the "dir" option.

Satisfies: SRG-OS-000062-GPOS-00031, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000473-GPOS-00218

Check

Verify RHEL 8 generates an audit record when successful/unsuccessful modifications to the "faillock" file occur. First, determine where the faillock tallies are stored with the following commands:

For RHEL versions 8.0 and 8.1:

$ sudo grep -i pam_faillock.so /etc/pam.d/system-auth

auth required pam_faillock.so preauth dir=/var/log/faillock silent deny=3 fail_interval=900 even_deny_root

For RHEL versions 8.2 and newer:

$ sudo grep dir /etc/security/faillock.conf

dir=/var/log/faillock

Using the location of the faillock log file, check that the following calls are being audited by performing the following command to check the file system rules in "/etc/audit/audit.rules":

$ sudo grep -w faillock /etc/audit/audit.rules

-w /var/log/faillock -p wa -k logins

If the command does not return a line, or the line is commented out, this is a finding.

Fix

Configure the audit system to generate an audit event for any successful/unsuccessful modifications to the "faillock" file by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file:

-w /var/log/faillock -p wa -k logins

The audit daemon must be restarted for the changes to take effect.