Cross-site request forgery (CSRF) vulnerability in system_firmware_restorefullbackup.php in the WebGUI in pfSense before 2.2.1 allows remote attackers to hijack the authentication of administrators for requests that delete arbitrary files via the deletefile parameter.
https://www.pfsense.org/security/advisories/pfSense-SA-15_04.webgui.asc
https://www.exploit-db.com/exploits/36506/
http://www.securityfocus.com/bid/73344
http://www.securityfocus.com/archive/1/534987/100/0/threaded