"The 4.3.1 untether exploit comes courtesy of Stefan Esser, a security researcher based in Germany. Stefan has a long history of vulnerability research, and ironically his first contribution to the iPhone jailbreak community was improved security, last year he beat Apple to the punch and implemented ASLR for jailbroken iPhones with his “antid0te" framework. We"re happy to see that Stefan then turned his iPhone attention over to an untethered jailbreak exploit!" Dev Team sdaid in its blog.
The new PwnageTool 4.3 and redsn0w 0.9.6 rc9 supports following
* iPhone4 (GSM)
* iPod touch 3G
* iPod touch 4G
* AppleTV 2G (PwnageTool only for now)
How ever, the new jailbreak will not work on Apple iPad 2. The reason the untether won"t work as-is on the iPad2 is that it requires a bootrom or iBoot-level exploit to install, and the iPad2 is not susceptible to either the limera1n or SHAtter bootrom exploits.
More over, users who are currently using ultrasn0w are requested not to update as the Dev Team has to release an update to ultrasn0w that fixes some incompatibilities when FW 4.3.1 is used on the older basebands supported by ultrasn0w. Users can download the redsn0w jailbreak by Clicking Here.