When I switch to VT 9 by pressing Ctrl+Alt+F9 I get a root shell by default without a password prompt. How can I change it to demand a password before giving root shell access? I am using Ubuntu 16.04 LTS.
In Sergiy's answer he has explained the methods to open VTs with and without
sudo and includes description of device files of VTs but he has not addressed this problem of mine where I have a default root shell on VT9.
lsof: WARNING: can't stat() fuse.gvfsd-fuse file system /run/user/1000/gvfs Output information may be incomplete. COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME bash 281 root 0u CHR 4,9 0t0 28 /dev/tty9 bash 281 root 1u CHR 4,9 0t0 28 /dev/tty9 bash 281 root 2u CHR 4,9 0t0 28 /dev/tty9 bash 281 root 255u CHR 4,9 0t0 28 /dev/tty9
systemctl status getty@9
● firstname.lastname@example.org - Getty on 9 Loaded: loaded (/lib/systemd/system/getty@.service; enabled; vendor preset: enabled) Active: inactive (dead) Docs: man:agetty(8) man:systemd-getty-generator(8) http://0pointer.de/blog/projects/serial-console.html