Apple has just released iOS 6.1.3 for iPhone, iPad, and iPod touch. The update brings a fix for a security bug that allows the home screen passcode to be bypassed through Passbook, as well as major map improvements in the Japan region. Jailbreakers beware, though, as it seems that Apple has also closed the software loophole that allows for the untethered jailbreak of iOS 6 in this version. If you're ready to update, head to the Settings apps, and then go into General, and select Software Update--or, just connect your iOS device to your PC or Mac and fire up iTunes.