Checkm8, by axi0mX, is a bootrom exploit for most modern iOS devices that was released earlier today, a little over 9 years since limera1n‘s release which was a bootrom exploit that worked on the iPhone 3GS/4 and other A4 devices. This exploit, which can be accessed from DFU mode, was patched by Apple in summer 2018 during the iOS 12 beta phase and makes use of a UaF (use-after-free) vulnerability found in iBoot’s USB code.
Checkm8 works on Apple A5 to A11 (included) devices which include:
Every iPhone from the iPhone 4S to the iPhone 8 (Plus)/iPhone X
The iPod Touch 5, 6 and 7
Every iPad from the iPad 2 to the iPad 7th generation (no word has been given on whether the exploit is compatible with the iPad 7th generation (released in 2019) but it’s doubtful that Apple has released a bootROM update for A10 devices as the iPod Touch 7 was released earlier this year after the bug was found and patched and is still vulnerable to it)
Every iPad Pro excluding the 2018 models
Every iPad Air excluding the iPad Air 3 (2019)
All iPad Mini devices excluding the iPad Mini 5 (2019)