MobileSafari in Apple iOS before 4.3 does not properly implement application launching through URL handlers, which allows remote attackers to cause a denial of service (persistent application crash) via crafted JavaScript code.
https://exchange.xforce.ibmcloud.com/vulnerabilities/66002
http://www.securitytracker.com/id?1025182
http://www.securityfocus.com/bid/46806
http://support.apple.com/kb/HT4564
http://lists.apple.com/archives/security-announce/2011//Mar/msg00003.html