If you have an iOS device released between 2011 and 2017 – iPad, Apple Watch, iPod Touch, and Apple TV you are affected by a security flaw called “checkm8”.
This “unfixable” iPhone flaw capable of giving hackers deep access to hundreds of millions of iOS devices has been discovered by a security researcher.
The exploit gives the ability to permanently jailbreak devices – the ability to remove software restrictions imposed by Apple on iOS. Jailbreaking a phone means it allows bad actors to take over a device and install malware or stalkerware giving third party access to a device.
Checkm8 takes advantage of a security vulnerability in the initial code that runs first when an iOS device powers on. As the vulnerability is found in the device’s read-only memory (ROM) and not in the software, Apple is unable to fix the issue with an update. But the good news here is that this flaw is a ‘tethered exploit’, meaning that the jailbreak can only be triggered when connected to a computer via USB and the flaw goes away once the device restarts.
Security researcher AxiOmX said he discovered the exploit by reverse-engineering a patch Apple released in summer 2018 for the iOS 12 beta.
Apple is powerless to do anything about ‘checkm8’, short of recalling millions upon millions of affected devices. It’s one of the most significant exploits in recent years, potentially shaking the Apple ecosystem to its core. But does anyone really care about jailbreaking anymore?
“The main people who are likely to benefit from this are security researchers, who are using their own phone in controlled conditions. This process allows them to gain more control over the phone and so improves visibility into research on iOS or other apps on the phone,” says Robin Wood, an independent security consultant. “For normal users, this is unlikely to have any effect, there are too many extra hurdles currently in place that they would have to get over to do anything significant.”
If a regular person with no prior knowledge of jailbreaking wanted to use this exploit to jailbreak their iPhone, they would find it extremely difficult, simply because Checkm8 just gives you access to the exploit, but not a jailbreak in itself.
Apple has released iOS 12.4.1 recently so be sure to update all of your devices as soon as possible. This update addresses additional security flaws not related to jailbreak, you can read more about it here.
If you have any concerns or questions over your phone or device security, please do get in touch.