CVE-2013-2804 in TOP Server
Summary
by MITRE
The DNP Master Driver in Software Toolbox TOP Server 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.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 05/10/2017
The vulnerability identified as CVE-2013-2804 affects the DNP Master Driver component within Software Toolbox TOP Server versions prior to 5.12.140.0, representing a critical security flaw that exposes industrial control systems to targeted denial of service attacks. This vulnerability specifically impacts the DNP3 protocol implementation used in industrial automation and control systems, where the master station functionality becomes trapped in an infinite loop when processing malformed or specially crafted packets. The affected system operates on TCP port 20000 for network-based attacks and also exposes a serial line interface vulnerability that can be exploited by attackers with physical proximity to the device. This dual attack vector significantly expands the potential threat surface for industrial control environments where such systems are deployed.
The technical flaw manifests through improper input validation within the DNP Master Driver's packet processing logic, where the system fails to adequately sanitize or validate incoming DNP3 frames before processing them in the master station context. When crafted malicious packets are received through either the TCP port 20000 interface or the serial line, the driver enters an infinite loop condition that consumes all available system resources and effectively renders the master station non-functional. This behavior constitutes a classic denial of service vulnerability that can be exploited remotely through network access or locally through physical connection, making it particularly dangerous in operational technology environments where system availability is critical for industrial processes. The vulnerability maps directly to CWE-835, which addresses infinite loops in software systems, and represents a specific implementation weakness in the protocol handling layer of the industrial control software.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise entire industrial control processes that depend on the availability of the DNP3 master station functionality. In critical infrastructure environments such as power grids, water treatment facilities, or manufacturing plants, the denial of service condition can lead to cascading failures where automated control systems become unresponsive, requiring manual intervention and potentially resulting in significant operational downtime. The infinite loop condition typically consumes 100% of available CPU resources on the affected system, making it impossible for legitimate DNP3 communications to proceed while the system remains in a non-responsive state. This vulnerability directly impacts the availability and integrity of industrial control communications, potentially leading to safety hazards in environments where timely control responses are essential for operational safety.
Mitigation strategies for CVE-2013-2804 require immediate patching of the Software Toolbox TOP Server to version 5.12.140.0 or later, which contains the necessary input validation fixes to prevent the infinite loop condition. Network administrators should implement firewall rules to restrict access to TCP port 20000 to only authorized network segments and employ network segmentation to isolate industrial control systems from general network access. Physical security measures must be strengthened to prevent unauthorized access to serial line interfaces, including cable management and access controls around industrial equipment. Additionally, network monitoring should be enhanced to detect anomalous packet patterns that may indicate exploitation attempts, and system administrators should implement regular vulnerability assessments of industrial control systems to identify similar weaknesses in other components of the operational technology infrastructure. The remediation approach should align with NIST SP 800-82 guidelines for industrial control systems security and follow ATT&CK framework techniques related to privilege escalation and denial of service operations in industrial environments.