There have been a number of report of people being able to bypass the lock screen in iOS 7, Apple has now released a software update to fix in issue, in the form of the Apple iOS 7.0.2 update.
The Apple iOS 7.0.2 is a small update of just under 20MB in size, and is available for the iPhone 4, iPhone 4S, iPhone 5 and iPhone 5S and iPhone 5C, plus the iPad 2 and later.
Fixes bugs that could allow someone to bypass the Lock screen passcode.
Reintroduces a Greek keyboard option for passcode entry
You can find out more details about what is included in the iOS 7.0.2 update over at Apple.