CVE-2018-7842 in Modicon M580
Summary
by MITRE
A CWE-290: Authentication Bypass by Spoofing vulnerability exists in all versions of the Modicon M580, Modicon M340, Modicon Quantum, and Modicon Premium which could cause an elevation of privilege by conducting a brute force attack on Modbus parameters sent to the controller.
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Analysis
by VulDB Data Team • 09/23/2023
The CVE-2018-7842 vulnerability represents a critical authentication bypass issue classified under CWE-290, which specifically addresses authentication bypass through spoofing mechanisms. This vulnerability affects several key products in Schneider Electric's Modicon series including the M580, M340, Quantum, and Premium controllers, indicating a widespread impact across industrial control systems that are fundamental to critical infrastructure operations. The vulnerability stems from insufficient validation of authentication credentials when Modbus parameters are transmitted to these industrial controllers, creating a pathway for malicious actors to escalate privileges through brute force attacks.
The technical flaw manifests in the controller's handling of Modbus communication protocols where the system fails to properly authenticate and validate the legitimacy of incoming parameter requests. When Modbus commands are sent to these controllers, the authentication mechanisms do not adequately verify the source or integrity of the parameters, allowing attackers to potentially spoof authentication credentials or manipulate the parameter values to gain unauthorized access. This weakness is particularly concerning because Modbus is a widely used protocol in industrial environments for communication between devices and controllers, making the vulnerability exploitable across numerous operational technology systems.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can enable attackers to gain unauthorized access to critical industrial processes and potentially compromise entire control systems. An attacker who successfully exploits this vulnerability could modify controller parameters, alter process controls, or even cause physical damage to industrial equipment through manipulated commands. The brute force attack vector suggests that the vulnerability could be exploited systematically, potentially allowing for prolonged unauthorized access and control of industrial processes. This represents a significant risk to industrial cybersecurity, particularly in sectors such as manufacturing, energy, and water treatment where these controllers are extensively deployed.
Organizations should implement multiple layers of security controls to mitigate this vulnerability, including network segmentation to isolate critical controllers from general network access, implementing strong authentication mechanisms beyond the basic Modbus authentication, and deploying intrusion detection systems to monitor for suspicious Modbus traffic patterns. The mitigation strategies should also include regular firmware updates from Schneider Electric, network access controls, and monitoring of controller parameter changes to detect unauthorized modifications. Additionally, implementing the principle of least privilege and conducting regular security assessments of industrial control systems aligns with the recommendations in the NIST Cybersecurity Framework and supports the MITRE ATT&CK framework's approach to defending against credential theft and privilege escalation techniques.