Carrier Unlockers Beware: iOS 4.2.1 Checks Your Baseband Signature
by Joe White
November 25, 2010
Apple's latest software update, iOS 4.2.1, poses a threat to users who have employed a "carrier unlock" on their iPhone. As a result of this, carrier unlockers are urged to hold off updating their iPhone's iOS until the Dev-Team gives the thumbs-up.
A couple of days ago, we told you the Dev-Team had managed to jailbreak iDevices running iOS 4.2.1. The popular jailbreak tool, redsn0w, now supports iOS 4.2.1. However, the Dev-Team has urged ultrasn0w unlockers to hold off on updating their iPhone's firmware:
ultrasn0w unlock: After redsn0w is officially released with the new Cydia and kernel patches, we’ll be able to assess the unlock situation. It’s already looking very promising though, so expect the unlock for the 3G and 3GS to be coming this week. The i4 unlock is taking more effort though, and no further concrete info is available about that yet.Following this, it has been confirmed by Redmond Pie that iOS 4.2.1 comes with a baseband requirement. As Semaphore, the creator of the popular TinyUmbrella program notes:
It seems that Apple has decided to put a baseband requirement on iOS. So at this point, if you are using Saurik’s server or tiny umbrella and trying to restore 4.2.1 on an iPhone 4, you will end up in recovery mode and tiny umbrella will not be able to pull you out of recovery. In this case, you will have to restore 4.1 again or you will have to restore 4.2.1 stock and be tether jailbroken. (Of course, I recommend 4.1 and not bothering with 4.2.1 at all). If you are an unlocker, this is a no brainer. Do not update to 4.2.1 even to test it at this point.We'll be posting when it's safe for carrier unlockers to update to iOS 4.2.1. In the meantime, if you have implemented a carrier unlock on your iDevice, follow everyone's advice and don't update to iOS 4.2.1. If you have any questions or concerns, feel free to post them in the comments below.