I am trying to secure root access on my Ubuntu servers (running 14.04 desktop and 16.04 server). I would like to disable root access on all TTYs except TTY1. I know this can be done by editing /etc/securetty, and commenting out all devices except TTY1, but I am unsure about the
Local X displays. Should I comment those out as well? what about the
UART serial ports,
Serial Mux devices,
Chase serial card,
Cyclades serial cards, etc, etc.
There are so many devices so I am unsure as to how to deal with securing this file. Can you lead me in the correct direction as to what devices I should disable for a working system but root can only log in from TTY1?