CVE-2017-11672 in Local Discovery Server
Summary
by MITRE
The OPC Foundation Local Discovery Server (LDS) before 1.03.367 is installed as a Windows Service without adding double quotes around the opcualds.exe executable path, which might allow local users to gain privileges.
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Analysis
by VulDB Data Team • 02/19/2020
The vulnerability identified as CVE-2017-11672 affects the OPC Foundation Local Discovery Server (LDS) version 1.03.367 and earlier installations. This issue stems from improper handling of executable paths during the Windows service installation process, creating a privilege escalation vector that can be exploited by local attackers. The OPC Foundation LDS serves as a critical component in industrial automation environments, facilitating communication between OPC UA clients and servers by providing discovery services for OPC UA applications. The vulnerability specifically manifests in the installation script or configuration process where the path to the opcualds.exe executable is not properly quoted when registered as a Windows service.
The technical flaw resides in the Windows service registration mechanism where command line arguments containing spaces or special characters are not properly escaped or quoted. When the LDS installer creates the Windows service entry, it fails to wrap the executable path in double quotation marks, allowing for path manipulation attacks. This issue falls under CWE-78, which addresses improper neutralization of special elements used in OS commands, and specifically relates to the improper handling of command line arguments. The vulnerability is particularly dangerous because it allows local users to manipulate the service startup command, potentially executing arbitrary code with elevated privileges. Attackers can exploit this by creating malicious files or directories with names that match parts of the unquoted path, causing the system to execute their code instead of the legitimate OPC UA discovery server executable.
The operational impact of this vulnerability extends significantly within industrial control systems and manufacturing environments where OPC UA protocols are prevalent. Local users who might not have administrative privileges can potentially escalate their access level to system administrator status, providing them with complete control over the affected system. This privilege escalation capability undermines the security model of industrial environments where operational technology (OT) systems often operate with elevated privileges. The vulnerability affects the integrity and availability of OPC UA-based systems, as attackers could potentially disrupt operations or exfiltrate sensitive data from industrial processes. Organizations relying on OPC UA discovery services for networked industrial automation systems face significant risk from this vulnerability, as it enables attackers to gain unauthorized access to critical infrastructure components.
Mitigation strategies for CVE-2017-11672 should prioritize immediate patching of affected systems to version 1.03.367 or later, which properly addresses the unquoted service path issue. System administrators should conduct comprehensive audits of all installed OPC UA services to identify any instances where service paths are improperly quoted, as this vulnerability can affect similar installations beyond the specific LDS component. The remediation process should include verifying that all Windows services have properly quoted executable paths in their service configuration. Additional security measures include implementing least privilege access controls, monitoring service installation and modification activities, and conducting regular security assessments of industrial control systems. Organizations should also consider applying the principle of least privilege to service accounts, ensuring that services run with minimal required permissions. This vulnerability demonstrates the critical importance of proper input validation and command line argument handling in security-sensitive applications, particularly within operational technology environments where system integrity is paramount. The attack surface for this vulnerability aligns with ATT&CK technique T1068, which covers the exploitation of local privileges through service manipulation, making it a significant concern for organizations implementing industrial cybersecurity frameworks.