Race condition in Passcode Lock in Apple iOS before 4 on the iPhone and iPod touch allows physically proximate attackers to bypass intended passcode requirements, and pair a locked device with a computer and access arbitrary data, via vectors involving the initial boot.
https://exchange.xforce.ibmcloud.com/vulnerabilities/59637
http://www.securityfocus.com/bid/41016
http://support.apple.com/kb/HT4225
http://lists.apple.com/archives/security-announce/2010/Jun/msg00003.html