Checkm8 opens the door to a possible permanent jailbreak from iPhone 4S to iPhone X

A security researcher claims to have found an exploit that would allow permanent jailbreak on some devices.

The security researcher, ” axi0mX ” on Twitter, has released ” checkm8 “, which claims to be a bootrom exploit for iOS devices with A5-A11 chips .

This would be the first bootrom exploit released publicly by the iPhone 4 in 2010 and would pave the way for a permanent and non-patchable jailbreak on hundreds of millions of affected iOS devices. Because the bootrom is read-only, Apple cannot fix this type of exploit with a software update.

EPIC JAILBREAK: Introducing checkm8 (read "checkmate"), a permanent unpatchable bootrom exploit for hundreds of millions of iOS devices.

Most generations of iPhones and iPads are vulnerable: from iPhone 4S (A5 chip) to iPhone 8 and iPhone X (A11 chip). https://t.co/dQJtXb78sG

— axi0mX (@axi0mX) September 27, 2019

The bootrom exploit has many other possibilities on the affected devices, including the downgrade of the iOS versions without BLOB SHTH or APTicket, dual boot iOS and custom firmware execution, according to jailbreak enthusiasts.

This is significant news in the jailbreak community, as the latest bootrom exploit known as ” limera1n ” was released by George ” geohot ” Hotz almost a decade ago for devices with A4 and earlier chips, including iPhone 4, iPhone 3GS, the third- and fourth-generation iPod touch and original iPad.