The (1) mdare64_48.sys, (2) mdare32_48.sys, (3) mdare32_52.sys, and (4) mdare64_52.sys drivers in Fortinet FortiClient before 5.2.4 allow local users to write to arbitrary memory locations via a 0x226108 ioctl call.
http://www.securitytracker.com/id/1033439
http://www.securityfocus.com/archive/1/536369/100/0/threaded
http://www.fortiguard.com/advisory/mulitple-vulnerabilities-in-forticlient
http://www.coresecurity.com/advisories/forticlient-antivirus-multiple-vulnerabilities
http://seclists.org/fulldisclosure/2015/Sep/0
http://fortiguard.com/advisory/mulitple-vulnerabilities-in-forticlient