As promised, the Dev Team officially released iOS 4.2.1 unlock for iPhone 3G and iPhone 3GS users. The carrier unlock will work on basebands later than 05.13.04, that includes basebands 05.14.02 and 05.15.04.
Today we’re pleased to announce our free carrier unlock for iPhone3G/3GS owners with a baseband later than 05.13.04. The unlock for that baseband exploited the AT+XAPP command, thanks to a crash initially discovered by @sherif_hashim (@Oranav also found this crash). So what hole are we exploiting today, since Apple closed that AT+XAPP hole? Well, we’re exploiting the exact same hole!
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.
The Dev Team provided notable information for those who are interested in unlocking their iPhone 3G and 3GS devices. You may read all the details on their blog.