(adsbygoogle = window.adsbygoogle || []).push({}); iPhone Dev Team has just released PwnageTool 4.2 to bring untethered jailbreak for iOS 4.2.1 with the help of Greenpois0n exploit. As you know PwnageTool is a Mac OS X tool, this version support all iOS devices except iPod touch 2G.

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The highlight feature of Sn0wbreeze 2.2 is the new “Baseband Preservation Mode”. This new mode enables current iPhone 4, 3GS and 3G users to preserve their baseband while upgrading to iOS 4.2.1 so that they can unlock using existing version of Ultrasn0w.

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Also new in Sn0wbreeze 2.2 is the ability to play Pac-Man game to keep you busy while the custom IPSW is being built for your iPhone, iPad or iPod touch, along with the ability to change boot logos, thanks to GreenPois0n RC5/6 exploit. Fix for iBooks is also included.

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Supported device:
iPhone3G
iPhone3GS
iPhone4
iPhone4-Verizon
iPod touch 3G
iPod touch 4G
iPad
AppleTV 2G

Important note: If you rely on ultrasn0w unlock, you MUST use this version of PwnageTool which creates custom 4.2.1 firmware with preserving the unlockable baseband to be able to unlock your iPhone again using ultrasn0w 1.2

Steps:

Step 1: Download and install the latest version of iTunes.

Step 2: Now start iTunes and sync your iPhone with your PC so that it backs-up all your important data including settings, apps, music, contacts and photos.

Step 3: Download Sn0wbreeze 4.2 and the original iOS 4.2.1 firmware file for your version of iPhone or iPod touch (download links given below). Move all these files to your desktop.

Step 4: Start Sn0wbreeze and select “Expert Mode”.

Step 5: Sn0wbreeze will now ask you to browse for your .ipsw file. Select the correct iOS 4.1 firmware .ipsw file by clicking the “Browse” button. Sn0wbreeze will verify the selected file and then will present you with following screens.

Also check “Activate The iPhone” if you are on unofficial carrier and want Sn0wbreeze to hacktivate your phone.

Step 7: Now simply select “Build IPSW”. Sn0wbreeze will now create the custom .ipsw file for your iPhone which will be jailbroken.

Step 8: Now you will have to restore your iPhone to this custom firmware 4.1 that you just cooked using Sn0wbreeze for your iPhone. Click on your phone from the sidebar in iTunes and then press and hold left “Shift” button on the keyboard and then click on “Restore” (Not “Update” or “Check for Update”) button in the iTunes and then release the “Shift” button.

This will make iTunes prompt you to select the location for your custom firmware 4.2.1. Select that custom .ipsw file and click on “Open”.

Step 9: Now sit back and enjoy as iTunes does the rest for you. This will involve a series of automated steps. Be patient at this stage and don’t do anything silly. Just wait while iTunes installs the new iOS 4.1 on your iPhone. Your iPhone screen at this point will be showing a progress bar indicating installation progress. After the installation is done, iPhone will restart automatically and you should now have a fully jailbroken iPhone running on iOS 4.2.1.

You must login or register to view this content. PwnageTool 4.2 for Mac
You must login or register to view this content. iOS 4.2.1 for all iPhone, iPod touch, iPad and Apple TV 2G
You must login or register to view this content. Sn0wbreeze 2.2 for Windows
You must login or register to view this content. iOS 4.2.1 for iPhone, iPad, iPod touch
You must login or register to view this content. .NET Framework 3.5 (required to run Sn0wbreeze)

Sources: RedmondPie, CoveringWeb, Me(edited some stuff), Blackicehacks.com