Nmapping Link to heading
We start the box, and nmap it.
nmap:
nmap -sV 10.129.123.103
Starting Nmap 7.99 ( https://nmap.org ) at 2026-07-27 12:58 +0200
Nmap scan report for 10.129.123.103
Host is up (0.011s latency).
Not shown: 999 closed tcp ports (conn-refused)
PORT STATE SERVICE VERSION
23/tcp open telnet Linux telnetd
Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel
Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 13.21 seconds
Telnet is open for business. Let’s try to connect to it.
telnet 10.129.131.79
root as username, no password required.
This gives us instant root access to the box.