The iPhone Dev-Team has announced that it has succeeded in unlocking the iPhone 3G and 3GS on iOS 4.2.1. This latest unlock has been released and is available now on Cydia.
Be warned: the jailbreak voids your Apple warranty alongside a number of other risks as detailed on the iPhone Dev-Team website and also below.
It says the following on Dev-Team Blog:
It turns out that the very first iPad firmware 3.2.2 has baseband version 06.15.00 still vulnerable to AT+XAPP. The iPad baseband is built for the exact same baseband chip as the iPhone3G/3GS — they’re fully compatible! Some of us have been running 06.15 for weeks now on our iPhones in preparation for this release.
Since 06.15 is a higher version than 05.14 or 05.15 (where AT+XAPP is gone), anyone stuck at those versions can simply upgrade to 06.15 to unlock again! Luckily for us, Apple *still* provides the iPad FW 3.2.2 with this vulnerable baseband right from their own servers. (Grab it now, before they take it down!)
We’ve been busy updating both PwnageTool and redsn0w to make the baseband update as seamless as possible. 1. First up is “PwnageTool 4.1.3 Unlock Edition”. It has a special dialog box which will ask you if you want to update to the iPad baseband. You must already have the iPad 3.2.2 IPSW on your computer (see the above link)….so just point PwnageTool at it (or let it find it on its own if you’re in “simple” mode). 2. Directly after PwnageTool 4.1.3 is available, the official ultrasn0w repo http://repo666.ultrasn0w.com will be updated with ultrasn0w 1.2, which covers iPhone 4 baseband 01.59.00 and iPhone 3G/3GS basebands 04.26.08, 05.11.07, 05.12.01, 05.13.04 and now 06.15.00. 3. Finally, we’ll release an update to redsn0w today for those without Macs and can’t run PwnageTool. The new redsn0w will give you the option to update your baseband to 06.15 too. WARNING — YOU DO THIS AT YOUR OWN RISK! PLEASE UNDERSTAND THE CONSEQUENCES OF UPDATING TO 06.15. 1. There is no way to come back down from 06.15, and there’s no hiding the baseband version from Apple. You’ll be voiding your warranty in a very obvious way. 2. If some future baseband comes out with a critical fix, you won’t be able to update to it if it remains down in the 05.xx sequence (then again, you wouldn’t update to it if you wanted to keep your unlock anyway). 3. Starting with FW 4.2.1 if you have 06.15 on your iPhone you won’t ever be able to restore to stock firmware (it will fail). You’ll need to only restore to custom IPSWs (then again, if you’re unlocker you should already be doing that) Certainly don’t update to 06.15 if you don’t need to! Only do this if you need the unlock and you’re stuck on 05.14 or 05.15, and you’re willing to assume the above risks.