The Monitor Control Command Set kernel extension in the Display Drivers subsystem in Apple OS X before 10.10.4 allows attackers to execute arbitrary code in a privileged context via a crafted app that leverages control of a function pointer.
http://www.securitytracker.com/id/1032760
http://www.securityfocus.com/bid/75493
http://support.apple.com/kb/HT204942
http://lists.apple.com/archives/security-announce/2015/Jun/msg00002.html