As we reported earlier, both PwnageTool 4.2 for Mac and Sn0wbreeze 2.2 for Windows are now available which can preserve baseband, and jailbreak iPhone, iPad and iPod touch on iOS 4.2.1 firmware.
This new version of PwnageTool and Sn0wbreeze also incorporates kernel based GreenPois0n exploit, which means that you can now create untethered 4.2.1 custom firmware files without the upgraded baseband so that you can unlock with current version of Ultrasn0w.
Simply follow the step by step instructions in the video embedded below to create custom 4.2.1 IPSW file without the upgraded baseband to jailbreak your iOS device.
Once you are done with the jailbreak, you can unlock your iPhone 4, 3GS and 3G on the old baseband using Ultrasn0w 1.2.
NOTE: You can also use this with iPhones which are flashed on 06.15 baseband so you can restore with this CFW (custom firmware).
Download PwnageTool 4.2 for Mac
Download Sn0wbreeze 2.2 for Windows
Download iOS 4.2.1 for iPhone, iPad, iPod touch and Apple TV 2
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