CVE-2025-33242 in HGX
Summary
by MITRE • 03/24/2026
NVIDIA B300 MCU contains a vulnerability in the CX8 MCU that could allow a malicious actor to modify unsupported registries, causing a bad state. A successful exploit of this vulnerability might lead to denial of service and data tampering.
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Analysis
by VulDB Data Team • 05/04/2026
The vulnerability identified as CVE-2025-33242 affects the NVIDIA B300 MCU system, specifically within the CX8 MCU component that controls critical hardware functions. This flaw represents a significant security concern as it allows unauthorized modification of registry settings that are not officially supported or documented by the manufacturer. The vulnerability stems from insufficient access controls and validation mechanisms within the MCU's registry management system, creating an attack surface where malicious actors can manipulate system parameters beyond their intended scope. The CX8 MCU serves as a crucial component in embedded systems architecture, managing various hardware configurations and system states that directly impact overall device functionality and security posture.
The technical implementation of this vulnerability involves a lack of proper input validation and access restriction controls within the registry modification interface. When the CX8 MCU processes registry write operations, it fails to properly validate whether the requested modifications fall within supported parameter ranges or authorized configuration domains. This weakness enables attackers to craft malicious registry entries that can alter system behavior in unintended ways, potentially leading to system instability or complete operational failure. The vulnerability operates at the firmware level, making it particularly dangerous as it can persist across system reboots and is difficult to detect through standard network monitoring tools. This type of flaw aligns with CWE-284, which addresses improper access control mechanisms in software systems.
The operational impact of this vulnerability extends beyond simple denial of service conditions to include potential data tampering scenarios that could compromise system integrity and confidentiality. A successful exploitation could result in unauthorized modification of critical system parameters, leading to unpredictable behavior or complete system failure. The affected B300 MCU system may experience cascading failures where modifications to one registry value inadvertently affect other system components, creating a domino effect that amplifies the initial security breach. In industrial control systems or automotive applications where these MCUs are commonly deployed, such vulnerabilities could lead to safety-critical failures with potentially severe consequences. The attack vector typically involves direct hardware access or exploitation through firmware update mechanisms, making it particularly challenging to defend against in embedded environments where physical security controls may be limited.
Mitigation strategies for CVE-2025-33242 should focus on implementing robust access control measures and strengthening registry validation processes within the CX8 MCU firmware. System administrators should ensure that all firmware updates are applied promptly through official channels and that proper change management procedures are enforced for any registry modifications. The implementation of registry locking mechanisms and cryptographic verification of registry entries can help prevent unauthorized modifications from taking effect. Organizations should also consider implementing runtime monitoring systems that can detect anomalous registry behavior patterns and alert security personnel to potential exploitation attempts. Network segmentation and access control policies should be enforced to limit physical access to systems containing vulnerable MCUs, while regular security assessments should be conducted to identify and remediate similar vulnerabilities in the broader system architecture. These measures align with ATT&CK technique T1547.009, which focuses on registry run keys and startup folder modifications as common attack vectors in embedded systems environments.