Fabrication attacks: Zero-overhead malicious modifications enabling modern microprocessor privilege escalation
The wide deployment of general purpose and embedded microprocessors has emphasized the need for defenses against cyber-attacks. Due to the globalized supply chain, however, there are several stages where a processor can be maliciously modified. The most promising, and the hardest to inject the hardware trojan, is the fabrication stage. As modern microprocessor chips are characterized by very dense, billion-transistor designs, such attacks must be very carefully crafted. In this paper, we demonstrate zero overhead malicious modifications on both high-performance and embedded microprocessors. These hardware trojans enable privilege escalation through execution of an instruction stream that excites the necessary conditions to make the modification appear. The minimal footprint, however, comes at the cost of small window of attack opportunities. Experimental results show that malicious users can gain escalated privileges within a few million clock cycles. Moreover, no system crashes were reported during normal operation, rendering the modifications transparent to the end user.
Microprocessors, Trojan horses, Fabrication, Hardware, Kernel, Logic gates, Computer architecture, privilege escalation, Hardware trojans, fabrication attacks, microprocessors, zero overhead, malicious modification
Michail Maniatakos, "Fabrication attacks: Zero-overhead malicious modifications enabling modern microprocessor privilege escalation", IEEE Transactions on Emerging Topics in Computing, vol. , no. , pp. 0, 5555, doi:10.1109/TETC.2013.2287186