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.