AMD has issued a support article stating that its CPUs are not susceptible to the recently disclosed SPOILER vulnerability. Support Article PA-240 confirms initial beliefs that AMD processors were immune from this specific issue due to the different ways that AMD and Intel processors store and access data:
We are aware of the report of a new security exploit called SPOILER which can gain access to partial address information during load operations. We believe that our products are not susceptible to this issue because of our unique processor architecture. The SPOILER exploit can gain access to partial address information above address bit 11 during load operations. We believe that our products are not susceptible to this issue because AMD processors do not use partial address matches above address bit 11 when resolving load conflicts.
SPOILER, one of the latest in the line of speculative execution vulnerabilities that have called into question years of processor architecture design, describes a process that can expose the mappings between virtual and physical memory. That's not a complete issue in and of itself, but it allows other attacks such as Rowhammer to be executed much more quickly and easily.
The research paper that initially disclosed SPOILER earlier this month states that Intel CPUs dating as far back as the first generation Core-series processors are affected. Intel, however, has stated that the vulnerabilities described in the paper can be avoided. The company provided a statement to PC Perspective following our initial SPOILER reporting:
Intel received notice of this research, and we expect that software can be protected against such issues by employing side channel safe software development practices. This includes avoiding control flows that are dependent on the data of interest. We likewise expect that DRAM modules mitigated against Rowhammer style attacks remain protected. Protecting our customers and their data continues to be a critical priority for us and we appreciate the efforts of the security community for their ongoing research.