Unpatchable 'usbliter8' Exploit Breaks Apple A12 and A13 SecureROM Boot Chain

Security researchers at Paradigm Shift have published a working exploit, dubbed usbliter8, that achieves arbitrary code execution inside the SecureROM of Apple's A12 and A13 chips. That code is burned into the silicon at manufacture. No software update can reach it. Affected devices will carry this flaw for as long as they stay in use. This is not a remote attack.