[How To] Jailbreak iPhone iOS 4.2.1 “Untethered” With Redsn0w 0.9.7b1
The much anticipated iOS 4.2.1 untethered jailbreak is here although it is limited. The instructions below are meant for RedSn0w 0.9.7b1, a beta release of the so-called “backup plan” untethered jailbreak. This release is not the final release either, being a beta, and it requires a bit more effort than the eventual final release should. The jailbreak is also limited to the iPhone 4, iPad, and iPod Touch 4G. The following will provide step-by-step instructions on how to jailbreak your iPhone (or other iOS device) using RedSn0w 0.9.7b1.
IMPORTANT: If you require an unlock and not a JAILBREAK ONLY, do not proceed.
- usbmuxd (which you can download from here)
- a jailbroken (tethered) iOS 4.2.1 iPhone 4, iPad, or iPod Touch 4G. Full instructions for completing the tethered iOS 4.2.1 can be found here
- the official iOS 4.2b3 firmware file
- your SHSH blobs from 4.2b3 saved w/ Cydia (locally saved files aren’t supported yet)
Download Redsn0w 0.9.7b1 for Mac OS:
- Download Redsn0w 0.9.7b1 for Mac OS X
This guide is for information and educational purposes only. Use it at your own risk, we cannot be held responsible if anything goes wrong.
How To Jailbreak iPhone iOS 4.2.1 “Untethered” With Redsn0w 0.9.7b1:
Get usbmuxd unarchived and running. Pick a directory to unarchive it to, then using Terminal, navigate to the python-client subdirectory and start usbmuxd as shown below. (Technically, it isn’t necessary to start usbmuxd just yet, but there’s no reason not to start it and get it out of the way right off the bat)
If you’re having trouble reading the commands in the image, they are:
- chmod +x tcprelay.py (makes it executable)
- ./tcprelay.py -t 22:2222
Next, connect your iPhone 4, iPad, or iPod Touch 4G and launch RedSn0w.
RedSn0w will immediately request that you browse to and select your official iOS 4.2.1 firmware file. To do this, navigate to, select the file, and click “Next.”
RedSn0w will process the firmware file and inform you when it is ready to proceed.
Select the “Jailbreak Monte” option. You can uncheck “Install Cydia” as you were required to begin these instructions with a jailbroken iOS 4.2.1 device running Cydia. Redsn0w will again prompt you to point it to an iOS firmware file, this time for iOS 4.2b3.
Make sure your iPhone, iPad or iPod Touch 4G is OFF and click “Next”. Then follow Redsn0w’s instructions on how to put your device into DFU mode and sit back and let the process complete. Once the process is complete, you are done! You now have an untethered jailbroken iOS device! If you have any questions feel free to ask us in the comments below!