CVE-2024-33687 in NJ Series CPU Unit
Summary
by MITRE • 06/24/2024
Insufficient verification of data authenticity issue exists in NJ Series CPU Unit all versions and NX Series CPU Unit all versions. If a user program in the affected product is altered, the product may not be able to detect the alteration.
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Analysis
by VulDB Data Team • 06/27/2024
The vulnerability identified as CVE-2024-33687 represents a critical weakness in the authentication and integrity verification mechanisms of NJ Series CPU Units and NX Series CPU Units across all versions. This issue stems from insufficient validation of data authenticity within the embedded systems architecture, creating a fundamental security gap that allows malicious actors to manipulate user programs without detection by the affected devices. The vulnerability manifests when unauthorized modifications are made to user programs running on these industrial control systems, as the system fails to properly verify the integrity of the executing code.
From a technical perspective, this weakness directly relates to CWE-347, which addresses insufficient verification of data authenticity, and falls under the broader category of integrity validation failures in embedded systems. The affected products operate in industrial environments where program integrity is paramount for operational safety and security. When user programs are altered, the system's inability to detect such modifications creates a persistent threat vector that could lead to unauthorized behavior modification, potentially resulting in system compromise or operational disruption. The vulnerability affects the core authentication mechanisms that should ensure only legitimate, unmodified code executes within the CPU units.
The operational impact of this vulnerability extends beyond simple code tampering, as it fundamentally undermines the trust model of industrial control systems. In environments where these CPU units are deployed for critical infrastructure management, manufacturing processes, or safety-critical applications, the inability to detect program alterations poses significant risks. Attackers could potentially introduce malicious code that remains undetected, leading to unauthorized system behavior, data manipulation, or even physical safety hazards. The vulnerability's scope affects all versions of the NJ and NX Series units, indicating a systemic issue rather than a localized bug, which amplifies the potential attack surface across numerous industrial installations.
Security mitigation strategies should focus on implementing robust code integrity verification mechanisms that align with industrial security standards such as IEC 62443 and NIST SP 800-82. Organizations should deploy additional layers of security including secure boot processes, cryptographic signatures for program verification, and regular integrity checks that go beyond the basic system capabilities. The ATT&CK framework's T1070.004 technique for "Indicator Removal on Host" and T1553.001 for "Taint/Corrupt Data" are directly relevant to this vulnerability's exploitation potential. Implementing proper access controls, network segmentation, and regular security assessments will help reduce the risk of exploitation, while firmware updates from manufacturers should be prioritized to address the underlying authenticity verification shortcomings.