UIWebView in UIKit in Apple iOS before 6 does not properly use the Data Protection feature, which allows context-dependent attackers to obtain cleartext file content by leveraging direct access to a device's filesystem.
https://exchange.xforce.ibmcloud.com/vulnerabilities/78706
http://support.apple.com/kb/HT5503
http://lists.apple.com/archives/security-announce/2012/Sep/msg00003.html