Vulnerability Discussion
Without generating audit records specific to the security and mission needs of the organization, 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).
Check
Verify Ubuntu 22.04 LTS generates audit records for all modifications that affect "/etc/sudoers" by using the following command:
$ sudo auditctl -l | grep sudoers
-w /etc/sudoers -p wa -k privilege_modification
If the command does not return a line that matches the example or the line is commented out, this is a finding.
Note: The "-k" value is arbitrary and can be different from the example output above.
Fix
Configure Ubuntu 22.04 LTS to generate audit records for all modifications that affect "/etc/sudoers".
Add or modify the following line to "/etc/audit/rules.d/stig.rules":
-w /etc/sudoers -p wa -k privilege_modification
To reload the rules file, issue the following command:
$ sudo augenrules --load
Note: The "-k " at the end of the line gives the rule a unique meaning to help during an audit investigation. The does not need to match the example above.