Intel TDX module: MULTI-TENANT ISOLATION: An out-of-bounds read in the TDX module reachable by an authenticated user

Impact

MULTI-TENANT ISOLATION: An out-of-bounds read in the TDX module reachable by an authenticated user, leaking information across the TDX boundary. Read primitives inside the module are the ones to watch: they are the shape that leaks other trust domains' state.

Who can reach it

An authenticated user on the host.

What to do

Update the Intel TDX module. The TDX module is loaded by the SEAM loader at boot, so the practical rollout is: stage the new module, drain every trust domain off the node, and reboot. It is not a live-patchable component and running TDs cannot be migrated through it. After the update, every TD must re-attest because the TDX module SVN is part of the attestation report - so anything that pinned the old measurement will fail until you update your attestation policy too. No OEM BIOS release needed for the module itself, which makes this materially faster than a platform firmware update.

References