Apple just released iOS 6.3.1 today to patch the lock screen security hole bug on iOS devices. The update Fixes a bug that could allow someone to bypass the passcode and access the Phone app and brings Improvements to Maps in Japan. You can grab the update from your device software update section or just plugin into iTunes.
- iPhone 3GS and later
- iPad 2 and later
- iPod touch 4th generation and later
- iPhone 5