GPUThor Rowhammer Attack Defeats NVIDIA ECC Memory to Gain Host Root Access

Researchers bypass NVIDIA $NVDA GPU error correction memory to gain host root access. GPUThor uses non-uniform row hammering on GDDR6 workstation GPUs to defeat Error Correcting Code protections. Testing on an RTX A5000 generated up to 377,552 bit flips per gigabyte, roughly 500 times more than prior attacks. On an ECC-enabled RTX A6000, researchers achieved full host root privilege escalation in 1.1 minutes. NVIDIA $NVDA issued security guidance following the disclosure, but no patch currently exists to fix the underlying hardware vulnerability. "ECC still raises the bar and remains worth enabling, but it can no longer be treated as a sufficient defense." — University of Toronto Researchers. Hardware mitigations always look bulletproof on sales sheets until someone sits down with a custom timing pattern for 24 hours.