The Private Browsing feature in Safari in Apple iOS before 5.1 allows remote attackers to bypass intended privacy settings and insert history entries via JavaScript code that calls the (1) pushState or (2) replaceState method.
https://exchange.xforce.ibmcloud.com/vulnerabilities/73871
http://www.securitytracker.com/id?1026774
http://secunia.com/advisories/48377
http://secunia.com/advisories/48288
http://lists.apple.com/archives/security-announce/2012/Mar/msg00003.html
http://lists.apple.com/archives/security-announce/2012/Mar/msg00001.html