Edit: After half day, my wife’s Mac started having the same problem. I have then applied the solution that I found in the Apple
Apple Release iOS 7.0.2 With Lock Screen Security Flaw Fixed
Apple just pushed iOS 7.0.2 to the public meaning you can now update to 7.0.2 on your iPhone, iPad, and iPod touch. The update can be accessed over-the-air by going in to Settings > General > System Update.
The update fixes the issue of being able to bypass the lock screen with out knowing the passcode.