Security researchers have disclosed a previously unknown iPhone BootROM vulnerability that allows attackers to compromise the boot chain on several Apple devices, including systems powered by A12 and A13 processors as well as Apple Watch S4 and S5 chipsets. The flaw, demonstrated through a proof-of-concept exploit dubbed "usbliter8," combines a hardware weakness in a USB controller with a firmware configuration issue that affects BootROM security. 

According to the researchers, the iPhone BootROM vulnerability impacts Apple A12, A13, and Apple Watch S4/S5 platforms. While support for A12X and A12Z chips may be technically feasible, those devices were not included in the released implementat...