RHEL 9 must disable the user list at logon for graphical user interfaces.

Leaving the user list enabled is a security risk since it allows anyone with physical access to the system to enumerate known user accounts without authenticated access to the system.

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 RHEL 9 disables the user logon list for graphical user interfaces with the following command:

$ gsettings get org.gnome.login-screen disable-user-list

true

If the setting is "false", this is a finding.

Configure RHEL 9 to disable the user list at logon for graphical user interfaces.

Create a database to contain the systemwide screensaver settings (if it does not already exist) with the following command: Note: The example below is using the database "local" for the system. 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/02-login-screen

[org/gnome/login-screen] disable-user-list=true

Update the system databases:

$ sudo dconf update