Information
The GNOME Display Manager (GDM) is a program that manages graphical display servers and handles graphical user logins.
Rationale:
If a Graphical User Interface (GUI) is not required, it should be removed to reduce the attack surface of the system.
Impact:
Removing the GNOME Display manager will remove the GUI from the system.
Solution
Run the following command to remove the gdm package
# yum remove gdm