New Rowhammer Attack Puts GDDR6-Powered NVIDIA GPUs at Risk

Rowhammer attacks exploit vulnerabilities in DRAM hardware by causing targeted bit-flips, allowing attackers to bypass memory isolation and gain control over a device. These attacks were initially focused on CPUs and their associated DDR memory, such as DDR4. However, recent research indicates that NVIDIA GPUs are also vulnerable due to the fragile nature of the GDDR6 memory they use, which directly compromises the CPU host. Two independent research teams have discovered ways to exploit this decades-old memory vulnerability against modern graphics hardware, with trouble extending beyond the GPU itself. The “GDDRHammer” and “GeForge” groups have each developed functional exploits that use Rowhammer bit-flips in NVIDIA GPUs with GDDR6 memory to gain complete control over the host CPU’s memory. This attack can perform bit-flips on some NVIDIA GPU models, ranging from the “Ampere” to “Ada Lovelace” families of cards.

An attacker who succeeds in this can read and write anything stored in the machine’s main memory. Both teams have also introduced new Rowhammer techniques specifically designed for GPU architecture, achieving a significantly higher rate of bit-flips on GDDR6 memory than previous methods. The critical step in both exploit chains involves targeting the GPU’s memory allocator, using controlled bit-flips to corrupt the GPU’s page tables. Once these page tables are compromised, the attacker gains arbitrary read and write access to CPU memory, breaking down the security…