CVE-2025-33242 Overview
NVIDIA B300 MCU contains a vulnerability in the CX8 MCU that could allow a malicious actor to modify unsupported registries, causing a bad state. This firmware-level vulnerability affects the microcontroller unit and could lead to denial of service conditions and data tampering when successfully exploited.
Critical Impact
Successful exploitation may result in denial of service and data tampering through unauthorized modification of internal device registries.
Affected Products
- NVIDIA B300 MCU
- CX8 MCU Component
Discovery Timeline
- 2026-03-24 - CVE CVE-2025-33242 published to NVD
- 2026-03-25 - Last updated in NVD database
Technical Details for CVE-2025-33242
Vulnerability Analysis
This vulnerability (CWE-1234) exists within the NVIDIA B300's CX8 microcontroller unit, specifically in the registry handling mechanism. The flaw allows authenticated attackers with high privileges to modify unsupported registries via network access. While exploitation requires high complexity due to specific conditions that must be met, a successful attack can compromise both the integrity and availability of the affected device. The vulnerability does not expose confidential information but can place the device into a bad operational state.
Root Cause
The root cause stems from insufficient validation of registry modification requests within the CX8 MCU firmware. The microcontroller fails to properly restrict access to certain internal registries that should not be user-modifiable, allowing privileged attackers to alter these values and destabilize the device's operational state.
Attack Vector
The vulnerability is exploitable via the network attack vector, requiring the attacker to have high-level privileges on the target system. The attack complexity is high, meaning specific conditions must be met for successful exploitation. No user interaction is required once the attacker has established the necessary access. The attack must be performed by an authenticated user with elevated permissions who can send specially crafted requests to modify the unsupported registry values.
Due to the firmware-level nature of this vulnerability, exploitation involves direct interaction with the MCU's internal registry system. Attackers with sufficient privileges could send malformed or unauthorized registry modification commands to the CX8 MCU, causing it to enter an unstable state. For detailed technical information, refer to the NVIDIA Support Article.
Detection Methods for CVE-2025-33242
Indicators of Compromise
- Unexpected changes to MCU registry values or configuration states
- Device instability or unexpected reboots of B300 MCU systems
- Unusual network traffic patterns targeting MCU management interfaces
- Error logs indicating registry modification failures or state corruption
Detection Strategies
- Monitor MCU firmware logs for unauthorized registry access attempts
- Implement network traffic analysis to detect anomalous management interface communications
- Deploy integrity monitoring to detect unexpected configuration changes on B300 devices
- Review authentication logs for unusual privileged access patterns
Monitoring Recommendations
- Enable verbose logging on NVIDIA B300 MCU management interfaces
- Implement alerting for any registry modification events on CX8 MCU components
- Establish baseline configurations and monitor for deviations
- Conduct regular firmware integrity checks on affected devices
How to Mitigate CVE-2025-33242
Immediate Actions Required
- Review and restrict network access to B300 MCU management interfaces
- Audit accounts with high-privilege access to affected systems
- Implement network segmentation to isolate MCU management traffic
- Monitor for any indicators of compromise on affected devices
Patch Information
NVIDIA has released information regarding this vulnerability. System administrators should consult the NVIDIA Support Article for official patch availability and detailed remediation guidance. Apply firmware updates as soon as they become available from NVIDIA.
Workarounds
- Restrict network access to MCU management interfaces using firewall rules
- Limit high-privilege account access to essential personnel only
- Implement network segmentation to isolate B300 MCU devices from general network traffic
- Enable additional authentication controls for management interface access
# Example: Restrict network access to MCU management interface
# Implement firewall rules to limit access to trusted management hosts only
iptables -A INPUT -p tcp --dport <MCU_MGMT_PORT> -s <TRUSTED_MGMT_IP> -j ACCEPT
iptables -A INPUT -p tcp --dport <MCU_MGMT_PORT> -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
