SLEM 5 must generate audit records for all uses of the "umount" system call.

Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information.

At a minimum, the organization must audit the full-text recording of privileged commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise.

Verify SLEM 5 generates an audit record for all uses of the "umount" and "umount2" system calls with the following command:

     > sudo auditctl -l | grep 'umount'
     -a always,exit -F arch=b32 -S umount -F auid>=1000 -F auid!=-1 -F key=privileged-umount
     -a always,exit -F arch=b32 -S umount2 -F auid>=1000 -F auid!=-1 -F key=privileged-umount
     -a always,exit -F arch=b64 -S umount2 -F auid>=1000 -F auid!=-1 -F key=privileged-umount

If both the "b32" and "b64" audit rules are not defined for the "umount" syscall, this is a finding.

Note: The "key=" value is arbitrary and can be different from the example output above.

Configure SLEM 5 to generate an audit record for all uses of the "umount" and "umount2" system calls.

Add or modify the following lines in the "/etc/audit/rules.d/audit.rules" file:

-a always,exit -F arch=b32 -S umount -F auid>=1000 -F auid!=unset -k privileged-umount -a always,exit -F arch=b32 -S umount2 -F auid>=1000 -F auid!=unset -k privileged-umount -a always,exit -F arch=b64 -S umount2 -F auid>=1000 -F auid!=unset -k privileged-umount

To reload the rules file, restart the audit daemon:

     > sudo systemctl restart auditd.service

or issue the following command:

     > sudo augenrules --load