Apple iOS 7 came into being with a number of bugs, the most prominent of which allows people to bypass the lockscreen passcode. The specific bug could grant anyone access to certain applications on the iPhone, and even make calls.
Now, Apple has released iOS 7.0.2 to fix the lockscreen bug. The update also brings the Greek keyboard option for passcodes.
The update has been released for iPhone 4, 4S, 5, 5C, 5S, iPad (2nd gen. and above), iPod (5th gen.) and iPad Mini. The 17.4MB update requires a WiFi connection to download and install the update on any supported device.
The rollout is gradual, which means it could take a day or two to reach your device, but you can manually check it by navigating to Settings > General > Software update. If you want to manually download iOS 7.0.2, you can check the source below for direct download links.