Unrestricted file upload vulnerability in index.php in phpBP RC3 (2.204) and earlier allows remote administrators to inject arbitrary PHP code into an upload/banners/ file via a banners add operation that uploads the PHP code through an image_form parameter specifying a multiple-extension filename such as .jpg.vil.gif.php, which is stored in upload/banners/ under a different name, and executable via a direct request.  NOTE: a separate SQL injection issue could be leveraged to make this vulnerability reachable by remote unauthenticated attackers.