iOS 7 users can grab the recently released 7.0.2 update using iTunes or over-the-air (OTA). The firmware update from Apple includes a security fix that plugs holes which allow someone to bypass the lock screen passcode. The vulnerability was first disclosed by Jose Rodriguez on YouTube. Although it may be difficult to reproduce, the bug made it possible to bypass the passcode with a sequence of inputs.
The steps involve accessing the Control Center from the lock screen, then opening the alarm clock application. After this, holding down the sleep/wake button until the iPhone displays slide to power off leads to the next step. Touching the Cancel button and quickly double pressing the home button launches the app switcher without a passcode. Obviously, this provides access to any running or recently opened apps with no passcode entry required.