Ubuntu OS must generate audit records when successful/unsuccessful attempts to modify the /etc/sudoers file occur.

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).

Verify Ubuntu OS 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.

Configure Ubuntu OS 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 <keyname>" at the end of the line gives the rule a unique meaning to help during an audit investigation. The <keyname> does not need to match the example above.