On Thursday Saurik has launched an update for the Cydia Eraser tool, so that it can now be used to un-jailbreak iOS 9.3.3 if you used the Pangu jailbreak tool.
With the latest update, anyone with a jailbroken iOS 9.3.3 device can use Cydia Eraser to remove the jailbreak from their device, uninstall all Cydia tweaks and packages and restore their device to a clean non-jailbroken state, while residing on the same iOS version without going to the latest firmware.
Saurik officially re-branded Cydia Impactor into “Cydia Eraser” last month just before the English Pangu jailbreak tool was released that used an app called “Cydia Impactor” to sign and install an IPA for jailbreaking your device. When the name change occurred, Saurik only noted only partial support for the dated iOS 9.0. So the added support for iOS 9.3.3 this week is very welcoming without a shadow of a doubt.
This tool is also useful for anyone who has a jailbroken device they’re trying to sell, because it lets the seller sell the device as a “jailbreakable” device, which may add value to it if it gets sold to the right buyer.
How it works
Cydia Eraser appears to take advantage of the OTA update system. Saurik explains how it works in Cydia, and we’ve included the excerpt below:
Eraser uses the firmware archives provided by Apple for its “over the air” update feature. These files are ~2GB large, so Eraser goes to extreme lengths to minimize the amount of data it needs to download: most recoveries will require less than 10MB of transfer.
First, the update’s “bill of materials” is compared against the files on your device, generating a list of changes.
Then, all files on your device that have been modified or otherwise destroyed are downloaded directly from Apple.
In a series of carefully calculated file migrations, all new files are moved to the user partition, and all system data is moved back to the system partition.
Up until this point, the idea is that no changes to your system have been made that are “unsafe”: at any point, if Eraser fails/crashes or your device reboots, you can just run it again later.
Finally, all of the staged changes to the filesystem are “committed”, all user data is deleted, and iOS is told to run its “reset all content and settings”.
The idea is that this “critical window” lasts only the final few seconds of a process that lasts for multiple minutes.
(That said, I still highly recommend not at all “messing with” the app while it is running, and maybe if you have a lot of data this will take longer than I expect.)
When the device reboots, it will look as it did when you first turned it on; it will also no longer be “jailbroken”: if you want to jailbreak it, you will need to do so using a desktop jailbreaking tool.
What makes Cydia Eraser a better tool than iTunes is that the latter restores your device to the latest iOS 9.3.4 firmware, thereby removing the ability to jailbreak. On the other hand, Cydia Eraser restores your device completely while keeping it on the same iOS version.
iOS 9.3.3 is still being signed by Apple, which means that you can use iTunes to restore your device to this firmware without going to iOS 9.3.4. However, once Apple stops signing it, your best bet is to use Cydia Eraser to remove the jailbreak from your device.
The latest update of Cydia Eraser can be installed right now from Cydia. Do you plan on removing your jailbreak using this tool? Let us know in the comments below.