Apple officially stopped signing iOS and iPadOS 13.3.1 Tuesday evening, just one week after releasing iOS and iPadOS 13.4 to the general public as an over-the-air software update.
The closing of the signing window means those who’ve upgraded to the newer 13.4 firmware will be unable to downgrade to 13.3.1. This isn’t a big deal for most iPhone or iPad users, but it’s something that can be particularly unsettling for the jailbreak community as software updates frequently patch jailbreak-centric software exploits.
Jailbreak tools like unc0ver rely on frequently-released exploits to extend firmware support as Apple launches new versions of iOS. In the past couple of months, unc0ver has picked up support for iOS 13.0-13.3, leaving iOS 13.3.1 users in the dust. Now that iOS 13.4 is publicly available, the golden jailbreaker’s rule that is to ‘stay on the lowest possible firmware’ comes into focus again.
At the time of this writing, the lowest possible firmware that Apple continues to sign is iOS 13.3.1, but unc0ver doesn’t yet support this version of iOS. Fortunately, a promising new kernel bug proof of concept supporting iOS 13.3.1 has been shared by Twitter user @_simo36, and while it remains to be confirmed whether this bug can achieve tfp0 (read/write into the kernel memory), it can purportedly be accessed from sandbox.
It’s no secret that the checkra1n jailbreak tool the jailbreak community by storm. But despite being unfixable by Apple, it’s still always comforting to see a newfangled jailbreak demonstration, especially when it happens on Apple’s latest firmware and when checkra1n isn’t the method of pwnage.
A Tweet with an embedded video demonstration shared Monday afternoon by Twitter user @08Tc3wBB appears to demonstrate an iPhone X on iOS 13.3.1 beta 3 being jailbroken with the assistance of an unknown side-loaded jailbreak app.