Pod2G today explained in a blog post how the Corona Untethered jailbreak works
He said :
Apple has fixed all previous known ways of executing unsigned binaries in iOS 5.0. Corona does it another way.
For Corona, I searched for a way to start unsigned code at boot without using the Mach-O loader. That’s why I searched for vulnerabilities in existing Apple binaries that I could call using standard launchd plist mechanisms.
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:-)
We are awaiting the A5 untethered jailbreak (iPhone 4S and iPad 2 ).Pod2G is working hard on it .So, keep your fingers crossed.