The IOHIDFamily kernel extension in Apple iOS before 8 and Apple TV before 7 lacks proper bounds checking on write operations, which allows attackers to execute arbitrary code in the kernel's context via a crafted application.
https://support.apple.com/kb/HT6535
https://support.apple.com/HT204659
https://exchange.xforce.ibmcloud.com/vulnerabilities/96110
http://www.securitytracker.com/id/1030866
http://www.securityfocus.com/bid/69942
http://www.securityfocus.com/bid/69882
http://support.apple.com/kb/HT6442
http://support.apple.com/kb/HT6441
http://lists.apple.com/archives/security-announce/2015/Apr/msg00001.html
http://archives.neohapsis.com/archives/bugtraq/2014-10/0101.html
http://archives.neohapsis.com/archives/bugtraq/2014-09/0107.html
http://archives.neohapsis.com/archives/bugtraq/2014-09/0106.html