Database/Firmware, BMC & network fabric
AMD SEV-SNP firmware, guest teardown / UMC key seed handling: TENANT HANDOFF FAILURE
Impact
TENANT HANDOFF FAILURE. A malicious hypervisor can overwrite a guest's UMC seed such that memory belonging to an already-decommissioned confidential guest becomes readable. In a rented-GPU business the slot a customer just released is immediately resold; this says the previous tenant's plaintext - checkpoints, weights, prompts, keys still resident in DRAM - can be recovered after their VM is gone. It breaks the one property you cannot buy back with an apology, and it does so on a path your own automation exercises thousands of times a day.
Who can reach it
Malicious or compromised hypervisor / host root, acting after a confidential guest terminates. No access to the victim tenant needed at all - only control of the host they used to be on.
What to do
Same package as CVE-2024-21980 (AMD-SB-3011): hot-loadable SEV firmware 1.37.14 hex (Milan) / 1.37.24 hex (Genoa) with no reboot, or Platform Initialization firmware MilanPI 1.0.0.D / GenoaPI 1.0.0.C via OEM BIOS with a reboot. Prioritize this one over the rest of the batch. Until it is fixed, do not treat guest teardown as a memory-sanitization boundary - force an explicit scrub or a full host reboot between confidential tenants. The fix bumps TCB[SNP], so re-baseline attestation policies.
References
Related entries
- AMI MegaRAC SPx (IPMI handler): Arbitrary file upload and download through the BMC's IPMI handlerCVE-2023-34342 · AMI MegaRAC SPx (IPMI handler)Medium
- Intel TDX module: The TDX module is the software that stands between the host/VMM and every confidential VM on the boxCVE-2023-47855 · Intel TDX moduleMedium
- Cisco NX-OS CLI: Command injection giving root on the switch's underlying OS from an admin CLI sessionCVE-2024-20399 · Cisco NX-OS CLIMedium
- Intel TDX SEAM loader (Seamldr): Sensitive information is not cleared before a resource is reused in the SEAM loaderCVE-2024-21850 · Intel TDX SEAM loader (Seamldr)Medium
- AMD SEV-SNP firmware - input validation: Improper input validation in SEV-SNP lets a malicious hypervisor read orCVE-2024-21978 · AMD SEV-SNP firmware - input validationMedium
- AMD Power Management Firmware (PMFW) - guest VM input validation causing GPU reset: Improper input validation in AMD'sCVE-2024-36346 · AMD Power Management Firmware (PMFW) - guest VM input validation causing GPU resetMedium
This entry is curated: imported from vendor advisories with machine assistance, not yet individually verified. Confirm against your vendor's advisory before acting, and report anything wrong.