After the pass code bypass of iOS which is recently fixed by 6.1.3 version of iOS, Samsung Galaxy Phones has the security flaw in passcode which is described by Terence Eden who claims to found it.
Same method that have used iOS bypass of passcode which the help of emergency dialer the user can access the home screen bypassing the lock code. Samsung is aware of the security flaw and currently working on it to fix the issue.
This type of security flaw is not seen in the other Android Version but it does in the modified version of Samsung Android 4.1.2. Both Galaxy SII and SIII has the issue says the claimer. Eden also post how to access the home screen in locked screen in his website.