This exploit makes the screen go black and allows an attacker to plug the device into the computer via USB and access user's data without entering the passcode.
"The vulnerability is located in the main login module of the mobile iOS device (iPhone or iPad) when processing to use the screenshot function in combination with the emergency call and power (standby) button. The vulnerability allows the local attacker to bypass the code lock in iTunes and via USB when a black screen bug occurs," Mejri wrote. "The vulnerability can be exploited by local attackers with physical device access without privileged iOS account or required user interaction. Successful exploitation of the vulnerability results in unauthorized device access and information disclosure."
Apple has released iOS 6.1.3 beta 2 to developers which includes a fix for the first lock screen bug. It's likely that the new bug will also be addressed when iOS 6.1.3 is released.
Read More [via ArsTechnica]