Is there a untethered way to jailbreak an iPhone 3GS running iOS 4.2.1?
The phone has never been jailbroken before.
I need to be able to reverse it, so I am hoping that there is a way to do this without upping the baseband.
Ask Different is a question and answer site for power users of Apple hardware and software. It only takes a minute to sign up.Sign up to join this community
It looks like you are lucky. First of all you should get a utility called TinyUmbrella (http://thefirmwareumbrella.blogspot.com) and save your SHSHs which will allow you to install older firmware on the device, in case you manage to save them before Apple stops signing the SHSHs. Next, see http://jailbrea.kr to tell wether you can jailbreak or not. Lastly, find an apropriate guide to jailbreaking your device via http://iclarified.com