Download GreenPois0n RC5 To Jailbreak iOS 4.2.1 Untethered
The Chronic Dev Team have been working on an untethered iOS 4.2.1 jailbreak since quite some time. Instead of waiting for iOS 4.3 official release as initially expected, they have gone ahead and released GreenPois0n RC5 untethered jailbreak for iOS 4.2.1 on iPhone 4, 3GS, iPod Touch 4G, 3G, 2G, iPad, and Apple TV 2G.
Till now we could have an untethered iOS 4.2.1 jailbreak using Redsn0w 0.9.7 Beta 1’s Monte jailbreak (Redsn0w 0.9.7 Beta 6 being the latest version). Similar to the Monte jailbreak, GreenPois0n RC5 too is currently available only for Mac OS X users. Windows and Linux versions are expected soon. Update: GreenPois0n RC5 B2 For Windows available for download.
One main difference which sets GreenPois0n RC5 apart from Redsn0w is that you don’t need any SHSH blobs saved on Cydia to jailbreak using GP. Redsn0w 0.9.7 on the other hand required 4.2Beta3 hashes saved.
Warning for Unlockers: Updating to iOS 4.2.1 firmware will also update your baseband. Be aware that a baseband update will result in loss of your Ultrasn0w unlock. iPhone 3GS users who want to restore to a custom iOS 4.2.1 firmware should wait for PwnageTool or Sn0wbreeze.
Update: For those stuck on GreenPois0n Initialized screen, GreenPois0n RC5 B3 fixes this issue. Also Windows version of GreenPois0n is now available for download.
Download GreenPois0n RC5 B3 for Mac OS X
Download GreenPois0n RC5 B2 for Windows
Here is our step by step guide to jailbreak iOS 4.2.1 Untethered on iPhone, iPod Touch, and iPad using GreenPois0n RC5.