The IPv6 implementation in the kernel in Apple iOS before 7 allows remote attackers to cause a denial of service (CPU consumption) via crafted ICMPv6 packets.
https://support.apple.com/kb/HT6535
https://exchange.xforce.ibmcloud.com/vulnerabilities/87222
http://www.securitytracker.com/id/1029054
http://support.apple.com/kb/HT6442
http://support.apple.com/kb/HT6441
http://support.apple.com/kb/HT5934
http://support.apple.com/HT204244
http://secunia.com/advisories/54886
http://lists.apple.com/archives/security-announce/2015/Jan/msg00003.html
http://lists.apple.com/archives/security-announce/2013/Sep/msg00006.html
http://lists.apple.com/archives/security-announce/2013/Oct/msg00004.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