Vulnerability Discussion
A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to logout because of the temporary nature of the absence.
Check
Verify RHEL 9 initiates a session lock for graphical user interfaces when the screensaver is activated with the following command:
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.
$ gsettings get org.gnome.desktop.screensaver lock-delay
uint32 5
If the "uint32" setting is not set to "5" or less, or is missing, this is a finding.
Fix
Configure RHEL 9 to initiate a session lock for graphical user interfaces when a screensaver is activated.
Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following command:
Note: The example below is using the database "local" for the system, so if the system is using another database in "/etc/dconf/profile/user", the file should be created under the appropriate subdirectory.
$ sudo touch /etc/dconf/db/local.d/00-screensaver
[org/gnome/desktop/screensaver]
lock-delay=uint32 5
The "uint32" must be included along with the integer key values as shown.
Update the system databases:
$ sudo dconf update