Pod2g has decided to share a little more information on the hopefully soon to be released iPhone 4S and iPad 2 jailbreak. In a blog post, pod2g has answered a couple of questions that may have been on your mind as you await its release. One of the questions is how he has managed to get an untethered 4S and dev teams still haven’t released tools to achieve this at home?
pod2g has updated his blog with more details on how the Corona untether actually works. If the deep inner workings of exploits such as this interest you, it's definitely something you'll want to check out.
Using a fuzzer, I found after some hours of work that there's a format string vulnerability in the racoon configuration parsing code! racoon is the IPsec IKE daemon (http://ipsec-tools.sourceforge.net/). It comes by default with iOS and is started when you setup an IPsec connection.
Now you got it, Corona is an anagram of racoon :-) .
Thanks to pod2g and all his hard work, an untethered jailbreak is now available for the original iPad, iPhone 4, iPod touch 4, and older models. Both redsn0w and Corona have been updated to support the new, untethered jailbreak.
A few days ago, @pod2g gave the untether to both the iPhone devteam and the chronic devteam. We’ve put it into redsn0w 0.9.10 and PwnageTool, and the chronic devteam put it into a Cydia package (the same set of exploits is in all three).