CVE-2020-6985 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, these devices use a hard-coded service code for access to the console.
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Analysis
by VulDB Data Team • 05/11/2024
The vulnerability identified as CVE-2020-6985 affects Moxa PT-7528 and PT-7828 series industrial communication devices where the firmware versions contain a critical security flaw involving hardcoded credentials. This issue represents a significant weakness in the device's authentication mechanism that directly compromises system security and access control. The affected devices operate within industrial environments where network security is paramount, making this vulnerability particularly dangerous as it provides unauthorized access to critical infrastructure components.
The technical flaw manifests through the implementation of a hard-coded service code that grants console access to these industrial devices. This hardcoded credential is embedded within the firmware itself, making it impossible to change or update through normal administrative procedures. The presence of such hardcoded credentials violates fundamental security principles and creates a persistent backdoor that remains active regardless of system updates or security configurations. This type of vulnerability is classified as a hardcoded credential issue under CWE-798, which specifically addresses the use of hard-coded passwords or keys that should never be included in source code or firmware. The vulnerability exists at the firmware level, meaning that even if network-level security measures are properly configured, the device remains accessible through this predetermined code.
The operational impact of this vulnerability is severe and multifaceted within industrial control systems environments. Attackers who discover or reverse-engineer the hardcoded service code can gain immediate administrative access to the device console, enabling them to modify device configurations, access sensitive data, or disrupt operations. This access could allow for the modification of network parameters, enabling man-in-the-middle attacks or the creation of unauthorized network connections. The vulnerability directly impacts the confidentiality, integrity, and availability of the industrial communication infrastructure, potentially leading to operational disruptions, data breaches, or even physical safety risks in environments where these devices control critical processes. The risk is amplified in environments where these devices are deployed without proper network segmentation or additional security controls.
Mitigation strategies for this vulnerability require immediate action from system administrators and security teams responsible for industrial environments. The primary recommendation involves upgrading the firmware to versions that eliminate the hardcoded service code and implement proper authentication mechanisms. Organizations should also implement network segmentation to isolate these devices from critical network segments and deploy network monitoring tools to detect unauthorized access attempts. The implementation of additional security controls such as network access control lists and regular security audits can help detect potential exploitation attempts. This vulnerability aligns with tactics described in the MITRE ATT&CK framework under initial access and privilege escalation categories, where adversaries exploit weak authentication mechanisms to gain system access. Organizations should also consider implementing zero-trust network architectures that verify all access attempts regardless of network location or previously established credentials. Regular vulnerability assessments and firmware update schedules should be established to prevent similar issues from occurring in the future, as this represents a fundamental flaw in the device's security design that cannot be patched through configuration changes alone.