Information

Default Port: 23

PORT   STATE SERVICE
23/tcp open  telnet

Enumeration

nc -vn 192.168.1.2 23
timeout 0.1 bash -c "nc -nv 192.168.1.2 23"

nmap -p23 -sS 192.168.1.2
nmap -p23 -sVC 192.168.1.2

nmap -p23 --script="telnet-brute.nse" 192.168.1.2
nmap -p23 --script="telnet-encryption.nse" 192.168.1.2
nmap -p23 --script="telnet-ntlm-info.nse" 192.168.1.2

Connect

telnet 192.168.1.2 23

Trying 192.168.1.2...
Connected to 192.168.1.2.
Escape character is '^]'.
Debian GNU/Linux 11
debian login: peter
Password: 
Linux teste 5.10.0-20-amd64 1 SMP Debian 5.10.158-2 (2022-12-13) x86_64

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

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
Last login: Sat Feb  4 21:03:00 CET 2023 from kali.home on pts/21

peter@debian:~$ id
uid=1000(peter) gid=1000(peter) grupos=1000(peter)

Brute Force

hydra -l peter -P rockyou.txt telnet://192.168.1.2 -F -I