Apple has released iOS 7.0.2 for iPhone, iPod and iPad after one week of original iOS 7 release. This update fixes bugs that could allow someone to bypass the lock screen passcode. Another fix includes the reintroduction of a Geek keyboard option for passcode entry.
However, the bug that lets people to call from lock screen still exist.
The update is available over-the-air and requires WiFi connection. The update site is about 20MB.