AMD SEV-SNP - DIMM interposer variant of BadRAM (KU Leuven): MULTI-TENANT ISOLATION: A memory-bus interposer variant

Impact

MULTI-TENANT ISOLATION: A memory-bus interposer variant of the BadRAM aliasing attack against SEV-SNP. AMD's response is **WONTFIX** - the attack is declared outside the SEV-SNP threat model because it requires physical interposition on the memory bus.

Who can reach it

Physical access with a memory-bus interposer.

What to do

**No patch, and none coming** - AMD has scoped it out of the threat model. The operator control is physical: tamper-evident chassis handling, chain of custody, and not making confidential-computing claims that a tenant could reasonably read as covering an adversary with physical access to the DIMM slot. If a customer's threat model includes your own datacenter staff, this is a conversation to have explicitly rather than one to leave to the marketing page.

References