Lab: Exploiting FTP

Hi! I have a question 4 u!

I wanted to try accessing the FTP server (ProFTPD 1.3.5a) without brute-force (Lab: Exploiting FTP, PTSv2).
I found a module on Metasploit that I thought would work (exploit/unix/ftp/proftpd_modcopy_exec), but I get this error:

Exploit aborted due to failure: unknown: ip address - Failure copying from /proc/self/cmdline

Is it possible to attack the FTP service without brute-force in this lab?
Just curiosity.

Thanks!

PS: Alexis said in the video-lesson that it should be vulnerable and invited us to try.