source: https://www.securityfocus.com/bid/7218/info

Multiple path disclosure vulnerabilities have been reported in various PHP scripts used by PHP-Nuke. The issue occurs when an invalid URI parameter is passed to certain scripts. The affected scripts do not provide sufficient error handling for this circumstance and as such, may display an error page containing sensitive information path information.

http://www.target.com/modules.php?op=modload&name=Members_List&file=index&letter=All&sortby=uname1234