source: http://www.securityfocus.com/bid/19890/info The Book Catalog module for PHP-Nuke is prone to a vulnerability that lets attackers upload arbitrary files. Exploiting this issue may allow an attacker to compromise the application and the underlying system; other attacks are also possible. Book Catalog 1.0 is vulnerable; other versions may also be affected. http://www.example.com/modules/BookCatalog/upload.php Upload c99 or r57 shell scripts http://www.example.com/modules/BookCatalog/images/bookimg/c99safemod.php