WebKit in Apple iOS before 9.3 and Safari before 9.1 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted web site.
https://support.apple.com/HT206171
https://support.apple.com/HT206166
http://www.zerodayinitiative.com/advisories/ZDI-16-200
http://www.securitytracker.com/id/1035353
http://www.securityfocus.com/archive/1/537948/100/0/threaded
http://lists.apple.com/archives/security-announce/2016/Mar/msg00005.html
http://lists.apple.com/archives/security-announce/2016/Mar/msg00000.html