redsn0w Updated to 0.9.6b3 to Jailbreak iOS 4.2.1 for Developers

The iPhone Dev Team remains hard at work. Yesterday they released an updated version of PwnageTool (Mac only) to jailbreak iOS 4.2.1 GM. Today, they’ve updated redsn0w to 0.9.6b3 (Windows users) to jailbreak iOS 4.2.1 GM, but this is primarily for developers who want to do testing. It does not install the newest version of Cydia.

From the iPhone Dev Team’s blog:

Update #3: (Warning: if you use the ultrasn0w unlock, please read no further…this doesn’t apply to you yet!) We’ve made some updates to redsn0w to make it easier for jailbreak developers (and tinkerers) to get their programs ready for 4.2.1.  As noted above, the public version of Cydia (and MobileSubstrate too!) is not 4.2.1-compatible.  redsn0w will now let you install your own custom bundles independent of Cydia (the bundle can actually be Cydia if you’ve compiled it on your own).  These bundles can be up to 15MB in size, and should be in the form of a gzip-compressed tar file.

The new redsn0w 0.9.6b3 is available at:

It’s very important that you get the file permissions and ownerships right in your custom redsn0w bundles.  To give you a practical example of such a bundle, here’s one that includes OpenSSH, OpenSSL, and the basic apt installer programs:

redsn0w has also been updated to recognize the 4.2.1GM IPSWs.  *However*, as noted above, the 4.2.x jailbreak is not yet untethered for most devices!  That means until someone like @comex comes up with a way to untether it, you must use redsn0w (or a similar utility) to boot your device into a jailbroken 4.2.1 state. (The only exceptions to this are the iPhone3G, non-MC iPod touch 2G, and old-bootrom iPhone3GS.  redsn0w will jailbreak those untethered!)

With the above redsn0w and SSH bundle, jailbreak developers and tinkerers can jailbreak and SSH into their 4.2.1 devices, provided they’ve done a tethered boot (using redsn0w’s “Just boot tethered right now” option).

Note:  The Cydia that’s included in 0.9.6b3 is the same one as in 0.9.6b2, and so it will *not* work on 4.2.1.  Don’t try installing it on 4.2.1!  Instead, use the SSH bundle, or compile Cydia on your own. If you’re familiar with the apt utilities, you can use “apt-get” to install many programs from the command line.  Be sure to do “apt-get update” first to refresh your sources!