The title pretty much sums it all up. The much awaited Greenpois0n RC5 untethered jailbreak tool for iOS 4.2.1 has finally been released. Previously, we had reported that Greenpois0n was going to be released very soon as it is not compatible with iOS 4.3, and now its finally out.
The best thing about Greenpois0n RC5 is that it is going to be untethered upon release and it won't require you to have SHSH blobs of iOS4.3b3 saved on Cydia to achieve an untethered jailbreak. Previously the only way to get an untethered jailbreak on your iOS 4.2.1 running device was through Redsn0w 0.9.7 which needed SHSH blobs.
In simple words: An untethered jailbreak on your iOS device running iOS 4.2.1 can now be achieved straight out of the box.
Greenpois0n RC5 supports iPhone 3GS, iPhone 4, iPod touch 2G, 3G, 4G and the iPad.
Download Greenpois0n RC5 untethered jailbreak tool