The GNOME Display Manager (GDM) is a program that manages graphical display servers and handles graphical user logins. If a Graphical User Interface (GUI) is not required, it should be removed to reduce the attack surface of the system.
Solution
Run the following command to uninstall gdm3 : # apt purge gdm3 Impact: Removing the GNOME Display manager will remove the Graphical User Interface (GUI) from the system.