Description

NVIDIA ConnectX and Bluefield contain a vulnerability in a control register, where a user with VF access could cause improper access control for the register interface by sending a malicious command to the firmware. A successful exploit of this vulnerability might lead to denial of service.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "6.8",
  "pubDate": "2026-09-29T15:17:12.293Z",
  "pubdate": "2026-09-29T15:17:12.293Z",
  "executiveSummary": "This vulnerability involves improper access control within the control register interface of NVIDIA ConnectX and Bluefield network adapters.\nThe flaw allows an attacker with Virtual Function (VF) access to perform unauthorized operations on the register interface by submitting malicious commands to the device firmware.\nExploitation of this vulnerability primarily leads to a Denial of Service (DoS) state, potentially causing the network adapter to become unresponsive or crash.\nThis vulnerability is categorized as an improper access control issue, which facilitates unauthorized interaction with hardware registers that should otherwise be protected or restricted to privileged operations.\nAttackers require access to a Virtual Function on the affected hardware, meaning the primary risk is limited to multi-tenant or virtualized environments where malicious actors may have localized guest-level access.\nThe impact is significant for high-availability environments relying on ConnectX or Bluefield hardware, as a successful exploit can disrupt network connectivity for the host or other virtual functions associated with the affected device.\nRemediation requires specific firmware updates provided by NVIDIA, as the flaw resides within the communication path between the VF interface and the underlying device firmware.",
  "technicalDetails": "The vulnerability resides in the firmware-level implementation of the control register interface for NVIDIA ConnectX and Bluefield series adapters. Specifically, the firmware fails to sufficiently validate the legitimacy and scope of incoming commands originating from Virtual Function (VF) interfaces before executing them at the hardware register level.\nRoot cause analysis points to a lack of robust input sanitization and privilege checking within the register access management logic. Under normal operation, the interface is designed to restrict specific hardware registers to the physical function (PF) or to authenticated administrative operations. However, the existing firmware logic allows a user possessing only VF-level permissions to bypass these access control lists (ACLs) by encapsulating malicious operations within standard firmware command structures.\nThe attack flow begins when an attacker, positioned within a guest environment that has access to a mapped VF, crafts a malicious command payload. This payload is transmitted via the standard register access protocol to the device firmware. Because the device firmware does not perform an adequate privilege check to verify if the issuing VF has the necessary permissions to access or modify the target control register, the command is processed by the hardware.\nExploitation involves the attacker sending a series of specifically crafted commands designed to manipulate sensitive control registers. By triggering states that are either undefined or invalid for a VF to access, the attacker induces a firmware-level exception. This exception handling mechanism is not hardened against malformed inputs from non-privileged contexts, leading to an immediate halt or deadlock of the device firmware.\nThe post-exploitation impact manifests as a Denial of Service. The hardware becomes unresponsive to further commands, effectively severing network connectivity associated with the physical device or the affected VFs. Recovery typically requires a full device reset or a host reboot to clear the firmware error state, posing a significant risk to service availability in cloud-native or virtualized deployments where hardware partitioning is a standard security boundary. Because the vulnerability is situated at the firmware level, it is largely independent of the guest operating system kernel, making it a critical threat to the hardware-software isolation layer."
}