Gputhor

University of Toronto researchers break NVIDIA GPU ECC defenses with GPUThor Rowhammer attack

Researchers demonstrated a new Rowhammer variant called GPUThor that defeats NVIDIA's ECC memory protections on Ampere-class workstation GPUs, including the RTX A4000, A4500, A5000, and A6000. By using a non-uniform hammering pattern tuned to avoid triggering GDDR6's Target Row Refresh defenses, the attack generates far more bit flips than earlier concepts like GPUHammer, enabling denial-of-service conditions and root-level privilege escalation.