The LaunchServices component in Apple iOS before 9.2 and watchOS before 2.1 allows attackers to execute arbitrary code in a privileged context or cause a denial of service (memory corruption) via a malformed plist.
http://lists.apple.com/archives/security-announce/2015/Dec/msg00000.html
http://lists.apple.com/archives/security-announce/2015/Dec/msg00002.html
https://support.apple.com/HT205635