This is a security flaw in the Android phone’s from Samsung Phone, which allows an malicious user to bypass the security controls and get access to any app – even when the phone is "securely" locked with a pattern, PIN, password, or face detection.
Terence Eden found this weakness in the Samsung Android Phones. To bypass the screen lock in Samsung android phones like Galaxy S, Note etc.. you need to use a series of key press and issue some commands
According to Terence Eden, this flaw does not occur in stock Android from Google, but on in Samsung flavour of Android phones.
You might be able to reduce the time of display (yes, those flash seconds) which will increase the efforts of an attacker. This might help the attacker stop trying and thus will keep your phone safe