NVIDIA DGX-2 - SBIOS / SMM firmware: An out-of-bounds write in the Bds phase gives a privileged local user firmware
Impact
An out-of-bounds write in the Bds phase gives a privileged local user firmware code execution. This is firmware-level persistence: it survives OS reinstall, image re-flash and tenant handoff, and it is invisible to anything running above it. On a bare-metal GPU rental business it is the difference between wiping a node between tenants and not actually being able to.
Who can reach it
Local and already privileged - host root, or code that has reached the platform firmware/SMM path. It is not a first foothold; it is what turns a one-time root compromise into something you cannot remediate by reimaging.
What to do
Flash the fixed SBIOS from bulletin 5449. Cost: not live-patchable. Full node drain, host power cycle, and on DGX the SBIOS ships inside a firmware bundle alongside BMC and CPLD components, so budget 30-60 minutes of node downtime plus a post-flash health check. Firmware rollback protection means you cannot cleanly revert - stage on one node before the fleet.
References
Related entries
- NVIDIA DGX-2 - SBIOS / SMM firmware: An out-of-bounds access in the OFBD SMM handler against a preconditioned heapCVE-2023-0200 · NVIDIA DGX-2 - SBIOS / SMM firmwareHigh
- NVIDIA DGX-2 - SBIOS / SMM firmware: Privileged code can modify the ServerSetup NVRAM variable at runtime, alteringCVE-2023-0207 · NVIDIA DGX-2 - SBIOS / SMM firmwareHigh
- NVIDIA ConnectX / BlueField: Privilege escalation leading to arbitrary code execution via the management interfaceCVE-2025-23299 · NVIDIA ConnectX / BlueFieldMedium
- HGX / DGX GB200, GB300, B300 (BMC -> HMC): BMC admin can pivot to the HMC as administratorCVE-2025-23337 · HGX / DGX GB200, GB300, B300 (BMC -> HMC)Medium
- NVIDIA Nsight Graphics (ngfx component, Windows): An ngfx component resolves a DLL from an untrusted search path, soCVE-2025-23355 · NVIDIA Nsight Graphics (ngfx component, Windows)Medium
- NVIDIA DGX Spark (GB10) - SROOT / OSROOT root-of-trust firmware: A second out-of-bounds write in SROOT firmwareCVE-2025-33190 · NVIDIA DGX Spark (GB10) - SROOT / OSROOT root-of-trust firmwareMedium
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.