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At the Black Hat 2018 and DEF CON 26 security conferences held in Las Vegas last week, a security researcher detailed a backdoor mechanism in x86-based VIA C3 processors, a CPU family produced and sold between 2001 and 2003 by Taiwan-based VIA Technologies Inc. The affected CPU family was designed with PC use in mind but was more widely known for being deployed with point-of-sale units, smart kiosks, ATMs, gaming rigs, healthcare devices, and industrial automation equipment. The Rosenbridge backdoor mechanism Christopher Domas, a well-known hardware security expert, says that VIA C3 x86-based CPUs contain what he referred to as a "hidden God mode" that lets an attacker elevate the execution level of malicious code from kernel ring 3 (user mode) to kernel ring 0 (OS kernel). See here about CPU protection rings. Domas says that this backdoor mechanism —which he named Rosenbridge— is a RISC (Reduced Instruction Set Computer) co-processor that sits alongside the main C3 processor. Continue reading on OUR FORUM.