A security flaw discovered by Terence Eden on the Galaxy Note II with Android 4.1.2 allows hackers to briefly bypass the phone’s lock screen without needing a password. The flaw appears to be similar to a screen lock vulnerability in newer Apple devices, including the iPhone 5. Not all apps will open in this manner, a demo video shows that Google Play does not respond to the bug. Samsung has yet to confirm if any other Samsung devices are affected by the flaw, Eden said.
Source: https://thehackernews.com/2013/03/samsung-galaxy-note-ii-lock-screen.html