source: http://www.securityfocus.com/bid/50925/info

Simple Machines Forum is prone to an arbitrary-file-upload vulnerability because it fails to properly sanitize user-supplied input.

An attacker may leverage this issue to upload arbitrary files to the affected computer; this can result in arbitrary code execution within the context of the vulnerable application.

Simple Machines Forum 1.1.15 is vulnerable; other versions may also be affected. 

http://www.example.com/[patch]/FCKeditor/editor/filemanager/browser/default/browser.html?Type=File&Connector=connectors/php/connector.php