DISA STIGS Viewer

The Ubuntu operating system must enable the graphical user logon banner to display the Standard Mandatory DoD Notice and Consent Banner before granting local access to the system via a graphical user logon.

Overview

Finding ID Version Rule ID IA Controls Severity
V-238197 UBTU-20-010002 SV-238197r958390_rule   Medium
Description
STIG Date
Canonical Ubuntu 20.04 LTS Security Technical Implementation Guide 2025-05-16

Details

Check Text (C-41407r653764_chk)
Verify the Ubuntu operating system is configured to display the Standard Mandatory DoD Notice and Consent Banner before granting access to the operating system via a graphical user logon.

Note: If the system does not have a graphical user interface installed, this requirement is Not Applicable.

Check that the operating banner message for the graphical user logon is enabled with the following command:

$ grep ^banner-message-enable /etc/gdm3/greeter.dconf-defaults

banner-message-enable=true

If the line is commented out or set to "false", this is a finding.
Fix Text (F-41366r653765_fix)
Edit the "/etc/gdm3/greeter.dconf-defaults" file.

Look for the "banner-message-enable" parameter under the "[org/gnome/login-screen]" section and uncomment it (remove the leading "#" characters):

Note: The lines are all near the bottom of the file but not adjacent to each other.

[org/gnome/login-screen]

banner-message-enable=true

Update the GDM with the new configuration:

$ sudo dconf update
$ sudo systemctl restart gdm3