Last year, we covered the first known Rowhammer attack on GPUs, dubbed "GPUHammer," which proved that VRAM is also susceptible to bit flips. At the time, our story focused on how GPUHammer can cripple an AI model's accuracy from 80% to just 0.1% in an RTX A6000 with a single bit flip. Since then, two new Rowhammer attacks have surfaced that can gain root access to the CPU through your GPU, potentially compromising your entire system (story via Ars Technica).
These attacks are called "GDDRHammer" and "GeForge," as listed on the gddr.fail website. They both work quite similarly and share an identical end goal. But first, it's important to understand what Rowhammer is. Back in 2014, it was discovered that by constantly accessing rows of memory, you can induce a bit flip on purpose on neighboring rows. Since bits are stored as electrical charge, "hammering" them causes electrical interference that can flip 0s into 1s, or vice versa.
