CVE-2013-2789 in KEPServerEX Communications Platform
Summary
by MITRE
The Kepware DNP Master Driver for the KEPServerEX Communications Platform before 5.12.140.0 allows remote attackers to cause a denial of service (master-station infinite loop) via crafted DNP3 packets to TCP port 20000 and allows physically proximate attackers to cause a denial of service (master-station infinite loop) via crafted input over a serial line.
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Analysis
by VulDB Data Team • 05/09/2017
The CVE-2013-2789 vulnerability affects the Kepware DNP Master Driver component within the KEPServerEX Communications Platform, a widely deployed industrial communication server used in critical infrastructure environments. This vulnerability represents a significant security flaw that can be exploited by both remote and local attackers to disrupt industrial control systems. The affected version range spans prior to 5.12.140.0, indicating that organizations using older iterations of this industrial communication software face potential operational disruptions. The vulnerability specifically targets the DNP3 protocol implementation within the master station functionality, which is fundamental to how industrial systems communicate with remote terminals and control devices.
The technical flaw manifests as an infinite loop condition within the DNP Master Driver's packet processing logic. When the system receives specially crafted DNP3 packets on TCP port 20000, or when malformed input is transmitted over a serial connection, the master station enters a continuous processing loop that consumes excessive system resources. This behavior stems from inadequate input validation and error handling within the protocol parsing mechanism, creating a condition where the system cannot properly terminate processing of malformed packets. The vulnerability is classified as a denial of service issue because it prevents legitimate operations from proceeding, effectively rendering the affected communication system inoperable until manual intervention occurs.
The operational impact of this vulnerability extends beyond simple service disruption, particularly in industrial environments where continuous operation is critical. Organizations using KEPServerEX for supervisory control and data acquisition (SCADA) systems face potential cascading effects when master stations become unresponsive, as this can prevent data collection from remote terminals and disrupt control operations. The remote attack vector via TCP port 20000 means that adversaries can exploit this vulnerability from external networks, while the local serial line attack vector indicates that physical proximity to the system can also trigger the exploit. This dual attack surface significantly increases the risk exposure for industrial facilities that may not properly segment their networks or implement adequate physical security controls.
From a cybersecurity perspective, this vulnerability aligns with CWE-835, which covers infinite loops in software systems, and demonstrates how protocol implementation flaws can create severe operational impacts in industrial environments. The ATT&CK framework categorizes this as a Denial of Service technique, specifically under the T1499.004 sub-technique for Network Denial of Service, with potential for lateral movement if the affected system serves as a communication hub for other industrial components. The vulnerability also represents a significant concern for compliance with NIST SP 800-82 guidelines for industrial control systems, as it creates a persistent threat to system availability and operational continuity. Organizations should implement immediate mitigation strategies including patching to version 5.12.140.0 or later, network segmentation to restrict access to TCP port 20000, and monitoring for anomalous packet patterns that may indicate exploitation attempts.