An arbitrary file upload issue exists in Mara CMS 7.5. In order to exploit this, an attacker must have a valid authenticated (admin/manager) session and make a codebase/dir.php?type=filenew request to upload PHP code to codebase/handler.php.
https://www.exploit-db.com/exploits/48780
https://sourceforge.net/projects/maracms/
http://packetstormsecurity.com/files/159304/MaraCMS-7.5-Remote-Code-Execution.html