Saint ZombieLoad, Who Raised Other People's Data

Patron of Intel processors, internal buffers that never flush, and secrets that return from the grave.

Life

On 14 May 2019 researchers from TU Graz, imec-DistriNet and others presented ZombieLoad, one of the speculative-execution "MDS" attacks on Intel processors. During certain operations, the CPU's small internal buffers held on to data from other programs, and an attacker could make it "rise again" and spy on it, even across the barriers between processes and virtual machines. The defence required microcode, updates and, in some cases, disabling hyper-threading.

Prayer

O Saint ZombieLoad, who recalls the data the CPU thought buried, let our buffers empty before they change masters. Amen.

How to celebrate

Celebrated by updating microcode and the operating system, and weighing whether hyper-threading is worth the risk.

Data not buried well comes back to visit.