RISC-V business: 'GhostWrite' chip flaw detailed at Black Hat USA

The technical details have been published: https://ghostwriteattack.com/riscvuzz.pdf

    ; t0 = physical address, a0 = byte to be written
    vsetvli zero, zero, e8, m1
    vmv.v.x v0, a0
    ; encoded: 0x10028027
    vse128.v v0, 0(t0)

So it's really quite bad for those CPUs.

This article reads like they intentionally left out any details.

> The researchers estimate that disabling the specific extensions needed to block an attack could result in the loss of as much as 50% of the chip’s instruction set […]

Which extensions?