CVE-2025-33207 Overview
CVE-2025-33207 affects NVIDIA ConnectX and BlueField products. The vulnerability resides in a control register where improper access control allows a user with Virtual Function (VF) access to send a malicious command to the firmware. A successful exploit can trigger denial of service on the affected network adapter or data processing unit (DPU).
The issue is classified under CWE-1262 (Improper Access Control for Register Interface). Exploitation requires adjacent network access and low privileges, and no user interaction is needed. NVIDIA published the security report through its product-security repository.
Critical Impact
An authenticated adjacent attacker with VF access can crash or disrupt ConnectX and BlueField devices, degrading availability of the underlying network fabric and hosted workloads.
Affected Products
- NVIDIA ConnectX network adapters
- NVIDIA BlueField data processing units (DPUs)
- Firmware exposing the affected control register interface to virtual functions
Discovery Timeline
- 2026-09-29 - CVE-2025-33207 published to NVD
- 2026-09-29 - Last updated in NVD database
Technical Details for CVE-2025-33207
Vulnerability Analysis
The vulnerability exists in a control register within the firmware of NVIDIA ConnectX and BlueField devices. Access control on the register interface is insufficient when the caller uses a Virtual Function. Single Root I/O Virtualization (SR-IOV) allows a Physical Function (PF) to expose multiple VFs to guest operating systems or containers. VFs should be restricted to a narrow set of device operations.
A user holding VF access can issue a crafted firmware command that reaches privileged register state. The firmware processes the command without correctly validating the caller's privilege boundary. The condition leads to denial of service on the device, which can propagate to every tenant sharing the adapter or DPU.
The scope change (S:C) indicates the impact extends beyond the vulnerable component into other guests or the host. This makes the flaw relevant in multi-tenant virtualization and cloud environments where NIC and DPU sharing is standard.
Root Cause
The root cause is missing or incomplete access control checks in the firmware command handler for a specific control register. The register interface does not distinguish between commands originating from a trusted PF context and those issued through a VF context. Guidance for this weakness class is documented under CWE-1262.
Attack Vector
Exploitation requires the attacker to already hold access to a VF exposed by the adapter or DPU. This typically means control of a guest virtual machine or container with SR-IOV passthrough. The attacker then issues a malicious firmware command over the device interface. No user interaction is required, and the attack complexity is low. Additional technical detail is available in the NVIDIA product security advisory.
No public proof-of-concept code is available for CVE-2025-33207 at this time. Refer to the vendor advisory for firmware-level details.
Detection Methods for CVE-2025-33207
Indicators of Compromise
- Unexpected resets or link-state flaps on ConnectX or BlueField interfaces without corresponding cable, switch, or driver events.
- Firmware health-check failures, PCIe AER (Advanced Error Reporting) events, or mlx5_core errors in host kernel logs.
- VF-originated administrative commands that fall outside the tenant's normal operational profile.
Detection Strategies
- Monitor host kernel and hypervisor logs for mlx5 driver errors, VF reset events, and firmware command failures across tenant boundaries.
- Correlate NIC and DPU availability drops with the specific tenant, VM, or container mapped to the affected VF.
- Baseline the expected firmware command traffic from each VF and alert on anomalous command opcodes.
Monitoring Recommendations
- Enable device telemetry from mlnx-tools and NVIDIA Firmware Tools (MFT) to capture firmware error counters.
- Ship hypervisor, host, and DPU logs into a centralized analytics platform such as Singularity Data Lake for cross-tenant correlation.
- Track adapter firmware versions across the fleet and alert when hosts drop below the patched baseline.
How to Mitigate CVE-2025-33207
Immediate Actions Required
- Inventory all ConnectX adapters and BlueField DPUs and identify firmware versions currently deployed.
- Apply the firmware update referenced in the NVIDIA product security advisory as soon as validated in a staging environment.
- Restrict VF assignment to trusted workloads until every affected host is patched.
Patch Information
NVIDIA has published remediation guidance in the NVIDIA product-security repository. Refer to the NVD entry for CVE-2025-33207 and the CVE.org record for the authoritative list of affected firmware versions and fixed builds.
Workarounds
- Disable SR-IOV on affected hosts where VFs are not strictly required, eliminating the exposed attack surface.
- Consolidate untrusted tenants onto separate physical adapters to prevent scope-changing impact across sensitive workloads.
- Apply hypervisor-level policies that limit which guests can bind to VFs on ConnectX and BlueField devices.
# Example: disable SR-IOV on an affected ConnectX device (Linux host)
# Replace <pci-id> with the actual PCI address of the adapter
echo 0 | sudo tee /sys/bus/pci/devices/<pci-id>/sriov_numvfs
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
