CVE-2020-6983 in PT-7528
Summary
by MITRE
In Moxa PT-7528 series firmware, Version 4.0 or lower, and PT-7828 series firmware, Version 3.9 or lower, the affected products use a hard-coded cryptographic key, which increases the possibility that confidential data can be recovered.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 05/11/2024
The vulnerability identified as CVE-2020-6983 affects Moxa PT-7528 and PT-7828 series industrial networking devices, representing a critical cryptographic weakness that undermines the security posture of these industrial control systems. These devices operate in environments where network security is paramount, including manufacturing facilities, critical infrastructure, and industrial automation systems where unauthorized access could result in significant operational disruption or safety hazards. The vulnerability stems from the implementation of a hard-coded cryptographic key within the firmware versions mentioned, which violates fundamental security principles and creates a persistent attack vector that remains consistent across device deployments.
The technical flaw manifests through the use of a predetermined, static cryptographic key that is embedded within the device firmware rather than generating unique keys for each device or session. This approach directly contravenes industry best practices for cryptographic key management and aligns with CWE-327, which addresses the use of weak cryptographic algorithms and key management practices. The hard-coded nature of the key means that any individual who obtains the firmware image or gains sufficient access to the device's memory can extract the cryptographic key and subsequently decrypt communications, authenticate as the device, or manipulate secure data exchanges. This weakness is particularly concerning in industrial environments where these devices often handle sensitive operational data, configuration parameters, and control signals that require strong cryptographic protection.
The operational impact of this vulnerability extends beyond simple data confidentiality breaches, as it creates opportunities for attackers to gain unauthorized access to industrial control systems through multiple attack vectors. The presence of a hard-coded key enables persistent threats to establish long-term access to network segments, potentially allowing for reconnaissance activities, data exfiltration, or even manipulation of industrial processes. According to ATT&CK framework category TA0006 (Credential Access) and TA0005 (Defense Evasion), adversaries can leverage this vulnerability to extract credentials, establish backdoors, and maintain persistence within industrial networks. The vulnerability affects not just individual device security but also the broader network security posture, as compromised devices can serve as entry points for lateral movement throughout industrial control networks.
Organizations should immediately implement mitigation strategies that include firmware updates from Moxa to address the hard-coded key issue, network segmentation to limit the impact of potential compromise, and enhanced monitoring of network traffic for suspicious activities. The vulnerability also underscores the importance of secure device lifecycle management, including proper key rotation and cryptographic implementation practices. Given that these devices are often deployed in environments with limited network connectivity and long operational lifecycles, the remediation process must account for operational constraints while ensuring cryptographic security is restored. Security teams should also consider implementing additional layers of protection such as network access controls, intrusion detection systems, and regular security assessments to identify and address similar vulnerabilities in other industrial control system components.