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.

Check

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

$ systemctl status ctrl-alt-del.target

reboot.target
Loaded: masked (Reason: Unit reboot.target is masked.)
Active: inactive (dead)

If the "reboot.target" is loaded and not masked, this is a finding.

Fix

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

$ systemctl disable --now reboot.target
$ systemctl mask --now reboot.target