iPhone and iPad users running the latest iOS 6.1 platform can bypass the lock screen, even when a password is set. The flaw is relatively easy to exploit and this lets you bypass the security code and use the full Phone app. From there you have access to the address book, and the pictures app by trying to change a contacts picture. Apple promised to fix the bug in a forthcoming software update so perhaps they’ll fix this annoying glitch as well. Apple has faced a number challenges over the last year related to software errors and flaws on its flagship iPhone.
Source: https://thehackernews.com/2013/02/ios-61-hack-allows-iphone-lock-screen.html