In response to the unlock pattern security flaw discovered earlier by BGR, one of AT&T’s employees offered the quickest solution to fix this bypass until they will release a permanent fix. The phone is not officially released yet, it’s going to launch October 2nd, this Sunday.
For a temporary fix until they release a full patch update for its software you need to re-set your device time-out screen to the “Immediately” setting. This is done by going to the App Drawer -> Settings->Location and Security->Screen unlock settings->Timeout->Immediately.
Samsung and AT&T are aware of the user interface issue on the Galaxy S II with AT&T. Currently, when using a security screen lock on the device, the default setting is for a screen timeout. If a user presses the power button on the device after the timeout period it will always require a password. If a user presses the power button on the phone before the timeout period, the device requests a password – but the password is not actually necessary to unlock it.
Samsung and AT&T are investigating a permanent solution. In the meantime, owners of the Galaxy S II can remedy the situation by re-setting their time-out screen to the “immediately” setting. This is done by going to the Settings->Location and Security->Screen unlock settings->Timeout->Immediately.