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)