CVE-2018-7803 in TriStation Emulator
Summary
by MITRE
A CWE-754 Improper Check for Unusual or Exceptional Conditions vulnerability exists in Triconex TriStation Emulator V1.2.0, which could cause the emulator to crash when sending a specially crafted packet. The emulator is used infrequently for application logic testing. It is susceptible to an attack only while running in off-line mode. This vulnerability does not exist in Triconex hardware products and therefore has no effect on the operating safety functions in a plant.
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Analysis
by VulDB Data Team • 09/23/2023
The CVE-2018-7803 vulnerability represents a critical security flaw in the Triconex TriStation Emulator version 1.2.0, classified under CWE-754 which addresses improper checks for unusual or exceptional conditions. This vulnerability manifests as a potential denial of service condition that can cause the emulator to crash when processing specially crafted network packets. The Triconex TriStation Emulator serves as a specialized testing tool designed for application logic validation within industrial control systems, operating in an offline mode that allows developers and engineers to simulate system behavior without direct connection to operational plant equipment. The vulnerability specifically affects the emulator's packet handling mechanisms, where inadequate validation of incoming data structures fails to properly detect malformed or maliciously constructed packets that could trigger unexpected system behavior.
The operational impact of this vulnerability extends beyond simple system instability, as it creates potential risks for industrial environments that rely on comprehensive testing procedures before deploying changes to operational systems. While the vulnerability is limited to the emulator's offline operation mode and does not affect actual Triconex hardware products or their safety functions, it represents a concerning weakness in the testing infrastructure that could be exploited by attackers to disrupt development workflows. The emulator's infrequent usage pattern does not mitigate the risk, as any compromise of the testing environment could potentially lead to undetected flaws in application logic that might later manifest as more serious issues when deployed to actual operational systems. This vulnerability aligns with ATT&CK technique T1499.002 which involves network denial of service attacks, and specifically targets the availability aspect of the CIA triad within industrial control system security frameworks.
Security professionals should recognize that this vulnerability demonstrates a fundamental flaw in defensive programming practices, particularly in the area of input validation and error handling within industrial software components. The lack of proper exception handling and boundary checking in the emulator's network packet processing routines creates a pathway for attackers to intentionally destabilize the testing environment. Organizations utilizing Triconex TriStation Emulator must implement immediate mitigations including software updates from Triconex, network segmentation to isolate the emulator from general network traffic, and monitoring for unusual network activity patterns that might indicate exploitation attempts. The vulnerability's limited scope to offline mode operations suggests that proper network access controls and security boundaries should be implemented to prevent unauthorized access to the emulator environment, as this represents a potential attack vector that could be leveraged to compromise the integrity of the development process. This case highlights the importance of security considerations in all aspects of industrial control system development, including testing and simulation environments, which often receive less security attention despite their critical role in system reliability and safety.