CVE-2018-7849 in Modicon M580
Summary
by MITRE
A CWE-248: Uncaught Exception vulnerability exists in all versions of the Modicon M580, Modicon M340, Modicon Quantum and Modicon Premium which could cause a possible Denial of Service due to improper data integrity check when sending files the controller over Modbus.
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Analysis
by VulDB Data Team • 09/23/2023
The vulnerability identified as CVE-2018-7849 represents a critical uncaught exception flaw classified under CWE-248 that affects several legacy industrial controller models including the Modicon M580, M340, Quantum, and Premium series. This vulnerability manifests in the form of improper data integrity checks during file transfer operations conducted over the Modbus protocol, creating a significant security risk for industrial control systems. The affected devices operate within critical infrastructure environments where reliability and continuous operation are paramount, making this vulnerability particularly concerning for operational technology environments.
The technical implementation of this vulnerability stems from the controllers' failure to properly validate data integrity during file transmission processes. When files are sent to these controllers over Modbus protocol, the system does not adequately verify the integrity of the received data before processing it. This lack of proper validation creates a condition where malformed or malicious data packets can trigger unexpected behavior in the controller's execution flow, leading to system instability and potential service interruption. The flaw specifically impacts the exception handling mechanisms within the firmware, where exceptions that should be gracefully managed are instead allowed to propagate and cause system failure.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially compromise the integrity of industrial control processes. When a denial of service occurs, the affected controllers may become unresponsive, requiring manual intervention and potentially causing production line shutdowns or process disruptions. In critical infrastructure environments where these controllers manage essential functions such as power generation, water treatment, or manufacturing processes, such disruptions can lead to significant financial losses and safety risks. The vulnerability's exploitation requires minimal technical expertise, making it particularly dangerous as it can be leveraged by both malicious actors and accidental operators.
Mitigation strategies for CVE-2018-7849 should prioritize immediate firmware updates from the vendor, as these controllers are legacy systems that require specific patches to address the uncaught exception handling issues. Network segmentation and access controls should be implemented to limit the attack surface, restricting Modbus communication to authorized personnel and systems only. The implementation of network monitoring solutions capable of detecting anomalous Modbus traffic patterns can help identify potential exploitation attempts before they cause system disruption. Additionally, organizations should conduct comprehensive risk assessments to identify all affected controllers within their industrial control networks and develop incident response procedures specifically addressing this vulnerability. This remediation approach aligns with the NIST Cybersecurity Framework and follows the ATT&CK framework's methodology for addressing industrial control system vulnerabilities, particularly focusing on the persistence and execution domains where such flaws can enable broader compromise of operational technology environments.