iOS 4 GM Jailbroken on iPhone 3GS

Not even a day after the iOS 4 GM was released to developers, it has already been jailbroken.  Please note that this guide is for iPhone 3GS users only and will most likely not last that long as the GM version will be replaced on June 21.  The official release by the Dev Team will be available soon.  This apparently preserves your baseband so you can unlock your phone with ultrasn0w or blacksn0w.


  • PwnageTool (download)
  • firmware 4.0 GM for the iPhone 3GS
  • iTunes 9.2 Beta
  • Jailbreak bundle (download)  Place in ‘’
  • Latest Cydia build (download)

There are some things that should be mentioned.

  • you should have your SHSH-Blobs saved in order to reverse the update and be able to go back to 3.1.2
  • Old bootrom (untethered JB) iPhone 3GS required!
  • No lockdown patch => you need an official operator SIM to activate.
  • You need to restore the ipsw from a recovery mode on a jailbroken 3.1.2 or 4.0 Beta fw; Spirit JB doesn’t patch iBoot and cannot be used to restore to custom firmware.
  • You also need to replace Cydia bundle with a newer version because the one in PwnageTool 3.1.5 crashes on 4.0.

Extract the data.tar from deb in 7Zip or other tool and use ‘tar xpvf data.tar’ while in ‘’ directory to update Cydia bundle shipped with PwnageTool.

You need to be on 3.1.2 with redsn0w in order to jailbreak. You can’t jailbreak with 3.1.3 on spirit.


  1. Tyrem says

    I may be thinking ahead of myself here but do u guys think unlocking iPhone 4 will have the baseband issue like 3.1.3? I kno they will jailbreak it but I want one and I’m not a fan of AT&T…give me your take on this

  2. LEI Mobile says

    Chino this is not an official jailbreak from the dev team, so if you are unsure how to do it I would recommend you wait till the iPhone dev team releases the official version of pwnagetool.

  3. Chris says

    OS4 is working fine, but Cydia keeps crashing on startup. I updated the bundle in PwnageTool. Anyone have an idea as to what the problem could be?

  4. says

    Guys, keep in mind, this really isn’t iOS 4 GM. This shows up as beta 5 in our dev portal. It’s a Gold Master Candidate. Also, the Cydia you used is most definitely NOT the one Saurik has working on iOS 4 GM.

    I unfortunately have to wait like everyone else (even though I’m a developer) and I have to wait for the official Pwnage Tool update since I have my iPhone 3G over here and no bundle is out. Also, I don’t want to have to update AGAIN in 7 days.

    I can basically guarantee you that this iOS 4 build is NOT the Gold Master we will see in iTunes on June 21st. The iPhone Dev Center lists some known bugs in this latest build that Apple will have to squash by next Monday. (or mabe even next Sunday).

    I would hold off (even though I’m DYING TO TRY iOS 4!!!), it’s for the best.

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