Information
The Red Hat Enterprise Linux operating system must enable a user session lock until that user re-establishes access using established identification and authentication procedures.
Rationale:
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 log out because of the temporary nature of the absence.
The session lock is implemented at the point where session activity can be determined.
Regardless of where the session lock is determined and implemented, once invoked, the session lock must remain in place until the user re-authenticates. No other activity aside from re-authentication must unlock the system.
Solution
Edit or create the file /etc/dconf/profile/gdm and add the following:
user-db:user
system-db:gdm
file-db:/usr/share/gdm/greeter-dconf-defaults
Edit or create a file in /etc/dconf/db/gdm.d/ and add the following: _(This is typically /etc/dconf/db/gdm.d/00-screensaver)
[org/gnome/desktop/screensaver]
# Set this to true to lock the screen when the screensaver activates
lock-enabled=true
Run the following command to update the system databases:
# dconf update
Note: Users must log out and back in again before the system-wide settings take effect.
Additional Information:
Red Hat Enterprise Linux 7 Security Technical Implementation Guide
Version 3, Release: 4 Benchmark Date: 23 Jul 2021
Vul ID: V-204396
Rule ID: SV-204396r603261_rule
STIG ID: RHEL-07-010060
Severity: CAT II