A new unpatchable flaw in Apple chips opens the door to an iPhone jailbreak

European cybersecurity firm Paradigm Shift disclosed an unpatchable hardware vulnerability in Apple's A-series chips on May 15, 2024, which could enable jailbreaking of older iPhones. The flaw, dubbed "checkm8" by researchers, affects chips from the A5 to the A11 Bionic, meaning it impacts devices from the iPhone 4S up to the iPhone X. Paradigm Shift detailed a technique to exploit this vulnerability, allowing for the bypass of Apple's security measures and the installation of custom firmware or operating systems. This exploit is particularly significant because it resides in the boot ROM, a read-only memory that is part of the chip's hardware and cannot be fixed through software updates. The company stated that the exploit is "unpatchable" by Apple, meaning devices with these vulnerable chips will remain susceptible indefinitely. While the exploit requires physical access to the device and is primarily of interest to security researchers and those seeking to modify their devices, it highlights a persistent hardware-level security concern for millions of iPhone users. Paradigm Shift has not released the exploit publicly, citing potential misuse.