Soon after Apple released iOS 7 to the public on September 18th, a bug was discovered in the lock screen. The bug could be exploited to gain unauthorized access to the e-mail, messages, Twitter, Photos and more of an iOS 7 device, even if a passcode was in place. Today, Apple has released iOS 7.0.2 for iPhone, iPad and iPod touch to fix this bug. The update weighs in at roughly 17MB, so there’s nothing major there except the bug fix and the reintroduction of a Greek keyboard option for passcode entry.
A few days ago, yet another bug was discovered in iOS 7. This one allows an intruder to make calls through an iPhone on iOS 7 even if it is locked with a passcode. Exploiting this bug is simple, one just needs to bring up the emergency dialing option on the lock screen, dial the number that is to be called and repeatedly press the call button. The iPhone will display a black screen with the Apple logo and put the call through, even if its an international or premium number. The changelog of IOS 7.0.2 does not reflect that it fixes this bug as well, Apple will probably release a fix for it in the near future.
Read more about iOS 7.