RHEL 9 must prevent a user from overriding the Ctrl-Alt-Del sequence settings for the graphical user interface.

Documentable No

Rule ID SV-258032r1045117_rule

CCI References

CCI-000366

Discussion

A locally logged-in user who presses Ctrl-Alt-Del, when at the console, can reboot the system. If accidentally pressed, as could happen in the case of mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot.

Check Procedure

Note: This requirement assumes the use of the RHEL 9 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is Not Applicable.

Verify that users cannot enable the Ctrl-Alt-Del sequence in the GNOME desktop with the following command:

$ gsettings writable org.gnome.settings-daemon.plugins.media-keys logout
 
false
 
If "logout" is writable and the result is "true", this is a finding.

Fix Action

Configure RHEL 9 to disallow the user changing the Ctrl-Alt-Del sequence in the GNOME desktop.

Create a database to contain the systemwide graphical user logon settings (if it does not already exist) with the following command:

$ sudo touch /etc/dconf/db/local.d/locks/session

Add the following line to the session locks file to prevent nonprivileged users from modifying the Ctrl-Alt-Del setting:

/org/gnome/settings-daemon/plugins/media-keys/logout

Run the following command to update the database:

$ sudo dconf update