AMD Secure Processor - privilege check on write path: The ASP accepts an input value and performs a write

Impact

The ASP accepts an input value and performs a write without confirming the caller had sufficient privilege to ask for it. The result is an integrity loss inside the secure processor - a caller that should have been refused gets its write.

Who can reach it

Local, through the ASP's callable interface.

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