Hardware security researchers from University of Toronto have developed a new memory bit flipping technique that significantly improves on previously known attacks against GPU memory. The new method can defeat the error-correcting codes (ECC) defense used on enterprise Nvidia GPUs and can lead to root access on the underlying system.
Dubbed GPUThor, the technique falls in a category of attacks known as Rowhammer that exploits the cell density of modern random access memory (RAM) chips. The original Rowhammer attack was demonstrated against DDR3 and DDR4 chips back in 2015 and relies on an older observation that tightly packed rows of memory cells can sometimes leak electrical charges to adja...