PHP-Nuke versions 6.x through 7.2 have a flaw that allows for user level authentication bypass.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/33069/waraxe-2004-SA017.txt
Source: https://packetstormsecurity.com/files/33069/waraxe-2004-SA017.txt.html