PHP-Fusion 6.00.306 and earlier, running under Apache HTTP Server 1.3.27 and PHP 4.3.3, allows remote authenticated users to upload files of arbitrary types using a filename that contains two or more extensions that ends in an assumed-valid extension such as .gif, which bypasses the validation, as demonstrated by uploading then executing an avatar file that ends in ".php.gif" and contains PHP code in EXIF metadata.
https://exchange.xforce.ibmcloud.com/vulnerabilities/26388
http://www.vupen.com/english/advisories/2006/1735
http://www.securityfocus.com/archive/1/433277/100/0/threaded
http://www.php-fusion.co.uk/news.php