Vulnerability Discussion

A user who is at the console can reboot the system at the login screen. If restart or shutdown buttons are pressed at the login screen, this can create the risk of short-term loss of availability of systems due to reboot.

Check

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 RHEL 9 prevents a user from overriding the disable-restart-buttons setting for graphical user interfaces.

$ gsettings writable org.gnome.login-screen disable-restart-buttons

false

If "disable-restart-buttons" is writable and the result is "true", this is a finding.

Fix

Configure RHEL 9 to prevent a user from overriding the disable-restart-buttons setting for graphical user interfaces.

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 prevent nonprivileged users from modifying it:

/org/gnome/login-screen/disable-restart-buttons

Run the following command to update the database:

$ sudo dconf update