New iPhone BootROM Flaw Enables Hardware-Level Compromise

The report details a proof-of-concept exploit named "usbliter8" that abuses a DMA pointer/reset flaw in the Synopsys DesignWare USB2 (DWC2) controller to trigger buffer underflows and controlled memory corruption on Apple A12, A13, and Apple Watch S4/S5 devices. Researchers achieved SecureROM code execution (including EL1 privileges), built ROP chains and bypasses for PAC-protected platforms, and demonstrated persistent BootROM modifications allowing unsigned iBoot images; because the vulnerability resides in immutable BootROM/SecureROM, affected devices remain permanently exposed and hardware replacement is the primary mitigation.