AMD Secure Processor TEE - memory cleanup between trusted applications: MULTI-TENANT ISOLATION: The ASP's trusted

Impact

MULTI-TENANT ISOLATION: The ASP's trusted execution environment fails to scrub memory between uses, so an attacker able to get a validly signed trusted application loaded can read or poison residue left by a previous TA. On a platform where the ASP handles fTPM state and SEV key material, that residue is exactly the material you least want leaking sideways.

Who can reach it

Local and privileged: the attacker must be able to produce and load a validly signed trusted application, which normally means a signing-key or supply-chain compromise rather than plain root.

What to do

Fixed in AMD reference firmware (AGESA / SEV firmware) and delivered to you only as an OEM SBIOS/BIOS package - Dell, HPE, Supermicro, Lenovo, Gigabyte and the ODMs each rebuild and requalify AMD's AGESA drop before it ships. **Expect months, not weeks**: AMD publishes the bulletin, the OEM ships BIOS somewhere between one and six months later, and for platforms past their support window it may never arrive at all. Applying it is a full node power cycle with the host drained - not a driver reload, not a live patch. Track it as a firmware campaign per server SKU, not per kernel version, and verify afterwards by reading back the SMU/PSP firmware version rather than trusting the BIOS revision string.

References