CVE-2019-6531 in PR100088 Modbus Gateway
Summary
by MITRE
An attacker could retrieve passwords from a HTTP GET request from the Kunbus PR100088 Modbus gateway versions prior to Release R02 (or Software Version 1.1.13166) if the attacker is in an MITM position.
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Analysis
by VulDB Data Team • 05/09/2020
The CVE-2019-6531 vulnerability affects the Kunbus PR100088 Modbus gateway device, specifically versions prior to Release R02 or Software Version 1.1.13166. This represents a critical security flaw in industrial network communication systems where sensitive authentication credentials can be exposed during transmission. The vulnerability manifests when an attacker successfully positions themselves in a man-in-the-middle configuration, enabling them to intercept and extract password information from HTTP GET requests. This issue directly impacts the confidentiality and integrity of communication within industrial control systems, as it allows unauthorized parties to gain access to authentication credentials without requiring sophisticated attack techniques.
The technical flaw stems from inadequate encryption and authentication mechanisms within the HTTP communication protocol implementation of the Modbus gateway. When the device processes HTTP GET requests containing authentication parameters, it fails to properly secure these credentials, making them visible to any network observer positioned between the client and server. The vulnerability is classified under CWE-312, which deals with cleartext storage or transmission of sensitive information, and aligns with ATT&CK technique T1071.004 for application layer protocol usage. The weakness occurs at the network layer where HTTP requests are processed, specifically in the handling of authentication tokens and passwords within query parameters.
The operational impact of this vulnerability is significant for industrial environments that rely on Modbus communication protocols for supervisory control and data acquisition systems. An attacker with MITM capabilities can easily extract login credentials, potentially gaining unauthorized access to industrial control systems, leading to possible operational disruptions, data manipulation, or system compromise. This vulnerability affects the fundamental security posture of industrial networks, as it allows attackers to escalate privileges and potentially take control of critical infrastructure components. The exposure of authentication credentials through unencrypted HTTP GET requests creates a direct pathway for lateral movement within industrial networks and can facilitate more sophisticated attacks.
Organizations should immediately implement mitigations including upgrading to the patched Release R02 or Software Version 1.1.13166 of the Kunbus PR100088 Modbus gateway. Network segmentation and the implementation of proper encryption protocols such as HTTPS should be enforced to prevent cleartext credential transmission. Additionally, organizations should deploy network monitoring solutions to detect anomalous traffic patterns that may indicate MITM attacks. The vulnerability demonstrates the importance of secure communication practices in industrial environments and highlights the need for robust authentication mechanisms that prevent credential exposure during network transmission. Regular security assessments and vulnerability management programs should be implemented to identify and remediate similar weaknesses in industrial control system components.