iOS 4.2.1 Does Baseband Checks; ultrasn0w Out By Sunday?
Apple has defeated TinyUmbrella's iPhone 4 baseband protection by implementing a boot level signature check in iOS 4.2.1. It's probably unnecessary to reiterate the warning that's been out there since before the upgrade dropped, but unlockers should really, really avoid upgrading. Meanwhile, MuscleNerd wishes everybody a happy Thanksgiving
, and says he thinks the next version of ultrasn0w may be ready, at least for some users, as soon as Sunday.
Adventurous unlockers have already found that if they try to run iOS 4.2.1 on a device with an older baseband, it will show the message "An unknown error has occurred" and go into recovery mode. TinyUmbrella is no longer able to kick iPhones out of recovery for iOS 4.2.1 because the baseband nonce is now checked, just like the SHSH is checked for firmware revs. So at this point there's no way out of that except to install the new baseband (killing the unlock) or downgrading to iOS 4.1 (assuming one has saved SHSH blobs).
Help is on the way, though. MuscleNerd tweeted from the Thanksgiving table this morning to say he's making good progress
on ultrasn0w. iPhone 3G and 3GS unlockers may have a working ultrasn0w by "Sunday/Funday;" iPhone 4 users will have to wait a little longer.