As part of a new discovery, a security researcher found an exploit dubbed Checkm8 (to be pronounced Checkmate), which can allow for permanent jailbreaking of iPhones, starting from the older iPhone 4s to the iPhone X.
Checkm8 Jailbreak Exploit
The new ‘unpatchable’ flaw has been discovered by a security researcher going by the name ‘Axi0mx’ on Twitter. It has also been publically announced on GitHub.
Checkm8 targets the bootrom, which means that the exploit is present in the first code that runs on an Apple device.
Since the bootrom code is read-only, fixing the flaw is next to impossible, be it via overwriting or through 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
— ax🔥🌸mX (@axi0mX) September 27, 2019
The exploit works via USB, which means a person would need a computer to perform the exploit in the Apple devices. Furthermore, as per GitHub, users have been warned that the exploit could cause devices to brick.
What Devices Are Vulnerable?
As per the tweet by ‘Axi0mx’, Apple devices starting from the old iPhone 4S (with an A5 chipset) to the iPhone X (with the A11 chipset) are prone to Checkm8’s exploitation.
Furthermore, various iPad models and even the fifth-generation iPod Touch and later are vulnerable. This also means the newer iPhone XS and iPhone 11 series can’t be compromised.
The exploit can be used to jailbreak and downgrade iOS devices among other activities. And who knows if it brings some serious security threats. But while it potentially affects millions of iOS devices, the fact that it requires physical access would limit its reach.
Jailbreaking After A Long Time!
For those who don’t know, jailbreaking on iOS devices was quite common and popular a couple of years back.
People often performed jailbreaks on iPhones to get hold of features that were otherwise not present on the devices. To read more about it, you should head to over here.
Jailbreaking eventually became uncommon, until a recent jailbreaking vulnerability appeared, which was patched by Apple.
However, Checkm8 is not an easy boy that can be tamed and it is touted as one of the biggest iOS jailbreak vulnerabilities in past years. Apparently, it’s being received well by the jailbreaking community as Apple won’t be able to disable it without refreshing the hardware.
As a reminder, it was almost a decade back when a bootrom exploit (‘limera1n’) was found for iPhone devices such as iPhone 4, iPhone 3GS, the third- and fourth-generation iPod touch, and the original iPad.