SLEM 5 must disable the x86 Ctrl-Alt-Delete key sequence.

A locally logged-on user who presses Ctrl-Alt-Delete when at the console can reboot the system. If accidentally pressed, as could happen in the case of a mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot. In the graphical user interface environment, risk of unintentional reboot from the Ctrl-Alt-Delete sequence is reduced because the user will be prompted before any action is taken.

Verify SLEM 5 is not configured to reboot the system when Ctrl-Alt-Delete is pressed with the following command:

     > systemctl status ctrl-alt-del.target
     ctrl-alt-del.target
          Loaded: masked (Reason: Unit ctrl-alt-del.target is masked.)
          Active: inactive (dead)

If ctrl-alt-del.target is not masked, this is a finding.

Configure the system to disable the Ctrl-Alt-Delete sequence for the command line with the following commands:

     > sudo systemctl disable ctrl-alt-del.target

     > sudo systemctl mask ctrl-alt-del.target

Then, reload the daemon to take effect:

     > sudo systemctl daemon-reload