WebKit in Apple iOS before 5.1.1 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a crafted web site.
https://exchange.xforce.ibmcloud.com/vulnerabilities/75431
http://www.securityfocus.com/bid/53404
http://support.apple.com/kb/HT5282
http://secunia.com/advisories/47292
http://lists.apple.com/archives/security-announce/2012/May/msg00002.html
http://lists.apple.com/archives/security-announce/2012/May/msg00000.html
http://lists.apple.com/archives/security-announce/2012/Jun/msg00000.html