CVE-2017-17443 in Local Discovery Server
Summary
by MITRE
OPC Foundation Local Discovery Server (LDS) 1.03.370 required a security update to resolve multiple vulnerabilities that allow attackers to trigger a crash by placing invalid data into the configuration file. This vulnerability requires an attacker with access to the file system where the configuration file is stored; however, if the configuration file is altered the LDS will be unavailable until it is repaired.
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Analysis
by VulDB Data Team • 02/19/2020
The vulnerability identified as CVE-2017-17443 affects the OPC Foundation Local Discovery Server (LDS) version 1.03.370, representing a critical security flaw that undermines the availability and stability of industrial automation systems. This issue resides within the configuration file processing mechanism of the LDS component, which serves as a crucial element in OPC UA (Open Platform Communications Unified Architecture) networks for discovering and connecting OPC UA servers. The vulnerability stems from inadequate input validation and error handling within the LDS software, creating a path for malicious actors to exploit system instability through manipulation of configuration data.
The technical flaw manifests when attackers place invalid or malformed data into the configuration file that the LDS service reads during initialization or operation. This vulnerability is classified as a buffer overflow or input validation error, falling under CWE-121 for buffer overflow conditions and CWE-707 for improper neutralization of special elements. The attack vector requires local file system access, meaning an attacker must already have compromised credentials or physical access to the system hosting the LDS service. However, the impact is severe as the LDS service becomes completely unresponsive when encountering malformed configuration data, effectively rendering the discovery functionality of OPC UA servers unavailable within the network.
The operational impact of this vulnerability extends beyond simple service disruption, as it can severely compromise industrial control system availability and operational continuity. When the LDS service crashes due to invalid configuration data, all OPC UA servers that rely on this discovery mechanism become unreachable to clients until manual intervention occurs. This creates cascading failures in industrial environments where real-time data exchange and system connectivity are paramount for process control and monitoring operations. The vulnerability particularly affects environments using OPC UA for manufacturing execution systems, supervisory control and data acquisition systems, and other critical infrastructure applications where discovery services are essential for system operation.
Mitigation strategies for CVE-2017-17443 should focus on both immediate remediation and long-term security hardening approaches. The primary solution involves applying the security update provided by OPC Foundation to upgrade the LDS component to a version that properly validates configuration file inputs and implements robust error handling mechanisms. Organizations should also implement file integrity monitoring solutions to detect unauthorized changes to critical configuration files, utilizing tools that align with NIST SP 800-53 security controls for configuration management. Additional protective measures include restricting file system access permissions to the configuration files, implementing principle of least privilege access controls, and establishing regular backup procedures for configuration data to ensure quick recovery from malicious modifications. The vulnerability demonstrates the importance of secure configuration management practices and highlights the need for proper input validation in industrial control system components, aligning with ATT&CK technique T1078 for valid accounts and T1486 for data destruction.