iOS 4.2.1 Jailbreak And Unlock Update From The iPhone Dev Team

We’re basically just passing on some info here, but the iPhone Dev Team have updated their blog to let us all know what’s going on with the latest jailbreak and unlock. Basically, older devices are good to go, for jailbreaking. Newer devices are tethered only, for the time being. An untethered jailbreak for the “A4″ devices is in the works. All devices that need unlocking should stay away from iOS 4.2.1, until UltraSn0w is updated.

Here’s all the details from the iPhone Dev Team:

With Turkey Day a few days off, today Apple publicly released FW version 4.2.1.  As always, ultrasn0w unlockers please stay far far away from this official firmware (and all official firmware).  Wait for the ability to create custom 4.2.1. IPSWs that don’t update your baseband!  If you’re not an unlocker, read on!

The best news of all is for owners of iPhone3G, older iPhone3GS, and non-MC iPod touch 2G.  Due to a combination of our original pwnage2 exploit, the arm7_go exploit, 24kpwn, and limera1n, your device is “just as jailbreakable as ever.”  You reap the full benefit of an untethered 4.2.1 jailbreak.

Next are the owners of all the more recent devices.  The good news there is that due to geohot’s limera1n exploit, all recent devices can be jailbroken (this will be true until Apple released new hardware that fixes geohot’s limerain exploit in the bootrom).  The bad news is that right now, the 4.2.1 jailbreak is *tethered* on all of these recent devices.  A tethered jailbreak means that each time your device loses battery power or needs to be rebooted, you must attach it to a PC or Mac to boot into the jailbroken state.  @comex is working hard on a method that may untether the 4.2.1 jailbreak, but it will require you to have your 4.1 SHSH blobs in order to use it.  No word on how much more effort it will take though (please don’t bug @comex about it!).  (We also have an alternative method that may work, but @comex’s method is much more elegant.)

So when does all this 4.2.1 jailbreak action happen?  Well if you’re a JB developer or tinkerer, you’ve already probably used the redsn0w mentioned in our last post to jailbreak 4.2.1 and at least get SSH working.  But beyond that, there are still some last minute issues with MobileSubstrate and comex’s kernel patches that are being fixed.  We’ll tweet and post a blog update when it’s all available (we hate to give ETAs, but barring any unforeseen problems, probably later today).

In the meantime, please make sure you have your 4.1 SHSH blobs for all your devices.  These will be important even for firmware beyond 4.1 (using both comex’s method and our alternative, depending on how each of them turn out.)

ultrasn0w unlock: After redsn0w is officially released with the new Cydia and kernel patches, we’ll be able to assess the unlock situation.  It’s already looking very promising though, so expect the unlock for the 3G and 3GS to be coming this week.  The i4 unlock is taking more effort though, and no further concrete info is available about that yet.

You iPad owners are probably REALLY tempted to hit that update button, but just wait a little longer, and you’ll have the new jailbreak, (for all devices), in some form, shortly. Again, if you need to unlock your device, just forget about this about, until Ultrasn0w is updated.

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  • Garett7rw

    So can I update and then use limera1n to JB again??? 3GS

  • Anonymous

    No. You must wait for Redsn0w or Pwnage Tool updates. These tools use the limera1n exploit, but the limera1n tool will not work on iOS 4.2.1.

  • Garett7rw

    thanks for the quick response:)

  • Derka181

    Quick Question. if i have a iphone 3G that is on 4.1 (not jailbroken/ unlocked yet) will i be able to unlock it in a few days????? if so should i stay away from 4.2.1.

  • Anonymous

    Yes and YES! Always stay away from new firmware until you know there is a new jailbreak/unlock released.

  • Anonymous

    I wonder if that potential new “unlock” that will be released will also unlock the 3G with updated basebands or support a downgrade (via fuzzyband) for post 5.8 bootloaders?…any ideas?

  • Admin@MYP

    No, the new unlock won’t be able to unlock your 3G.

  • Bluemedkit

    Greetings lol. iTouch 2G. model MC086LL. serial 8L931G3575J. Version 4.1. green poison. i was thinking of upgrading to 4.2 and jailbreak with redsnow. will my jailbreak be thetered? any problem i should know about? i also wanted know if the custom bootlogo is possible with my device =)

  • T1andonly

    Just to be clear… I have an Ipod touch 2g MB model. Will green poison work if I update my ipod to the new 4.2.1 firmware?