AMD Secure Processor Secure OS - memory buffer checking: MULTI-TENANT ISOLATION: A malicious trusted application can

Impact

MULTI-TENANT ISOLATION: A malicious trusted application can read and write the ASP Secure OS's kernel virtual address space because buffer bounds are not checked at the TA boundary. That is full privilege escalation inside the secure processor - the attacker is now the security engine, not a client of it.

Who can reach it

Local, requires the ability to load a malicious trusted application into the ASP (signing-key compromise or a legitimately signed but attacker-controlled TA).

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