CVE-2020-6991 in EDS-G516E
Summary
by MITRE
In Moxa EDS-G516E Series firmware, Version 5.2 or lower, weak password requirements may allow an attacker to gain access using brute force.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 05/11/2024
The Moxa EDS-G516E Series network switch devices running firmware version 5.2 or lower present a significant security weakness through their inadequate password policy implementation. This vulnerability stems from the device's failure to enforce strong authentication requirements, creating an exploitable condition that allows malicious actors to systematically guess or crack administrative credentials through brute force attacks. The weakness represents a fundamental failure in access control mechanisms that directly compromises the device's security posture and potentially exposes the entire network segment it manages.
This vulnerability aligns with CWE-521 Weak Password Requirements, which specifically addresses the absence of adequate password strength controls in authentication systems. The device's configuration allows for the creation and use of easily guessable passwords, including common defaults, simple numeric sequences, or dictionary words that provide minimal cryptographic entropy. Attackers can leverage automated tools to rapidly test common password combinations, significantly reducing the time required to gain unauthorized administrative access to the device's management interface.
The operational impact of this vulnerability extends beyond simple unauthorized access, as the EDS-G516E series serves as a critical network infrastructure component that controls and manages network traffic flow. Successful exploitation could enable attackers to modify network configurations, redirect traffic, implement man-in-the-middle attacks, or establish persistent backdoors within the network. The device's role as a gateway device means that compromise could lead to lateral movement throughout the network, potentially affecting multiple systems and applications that rely on the network infrastructure for communication.
From an adversarial perspective, this vulnerability maps directly to ATT&CK technique T1110.001 Brute Force: Password Guessing, which describes the use of automated tools to systematically guess credentials. The low complexity of exploitation makes this attack vector particularly attractive to threat actors, especially those with limited technical expertise or resources. The vulnerability also intersects with T1078 Valid Accounts, as successful exploitation results in the acquisition of legitimate administrative credentials that can be used for extended access without detection.
Organizations should implement immediate mitigations including mandatory password complexity policies, account lockout mechanisms, and regular password rotation schedules. Network segmentation and monitoring should be enhanced to detect unusual authentication patterns that might indicate brute force attempts. The most effective long-term solution requires firmware updates to enforce strong password requirements, implement rate limiting for authentication attempts, and disable default accounts or require explicit credential changes upon first login. Additionally, organizations should conduct comprehensive network audits to identify all affected devices and ensure proper configuration management practices are implemented to prevent similar vulnerabilities in other network infrastructure components.