Yesterday pod2g reported that he is now working on porting his untether exploit to the iPhone 4S and the iPad 2 (devices with the A5 processor). He had some issues with the A5 caches, but after just one day of trying, it looks like the issue has been resolved.
OK, figured it out, the A5 cache is not a problem anymore.
I sorted it out by doing the untether in a single thread and by flushing all the dcache then all the icache in a row at a strategical point of the process.
It took me like a hundred of tests to find the key. Hard for the nerves.
Pod2g, hacker and former member of the chronic dev team, recently found an untether exploit in iOS 5. He now tweeted that people who would like to jailbreak their iOS 5 device shouldn’t update to Apple’s upcoming firmware version 5.0.1. Because Apple changed the way SHSH blobs work, you can no longer downgrade to a previous version of iOS, even if you saved your SHSH blobs. You can still downgrade to iOS 4 if you have those SHSH blobs saved, but if you want to upgrade to iOS 5, you can only get the most recent firmware.
Note about 5.0.1 : don’t update if you plan on jbking : the bug Charlie MILLER found can simplify exploits dramatically and will be closed.
Pod2g later tweeted: “I didn’t tell 5.0.1 would never be jbken but it will certainly take more time.”
We would still recommend to stay on iOS 5.0 until we know if iOS 5.0.1 will ever be jailbroken (if the bug is fixed in 5.0.1, the hackers will probably wait for the next major release to use their next exploit). A fix for the battery issues might also be released through Cydia after the jailbreak is out.