Vulnerability Discussion

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 a graphical user environment, risk of unintentional reboot from the Ctrl-Alt-Delete sequence is reduced because the user will be prompted before any action is taken.

Satisfies: SRG-OS-000324-GPOS-00125, SRG-OS-000480-GPOS-00227

Check

Verify RHEL 9 is not configured to reboot the system when Ctrl-Alt-Delete is pressed with the following command:

$ sudo systemctl status ctrl-alt-del.target

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

If the "ctrl-alt-del.target" is loaded and not masked, this is a finding.

Fix

Configure RHEL 9 to disable the ctrl-alt-del.target with the following command:

$ sudo systemctl disable --now ctrl-alt-del.target
$ sudo systemctl mask --now ctrl-alt-del.target