CVE-2023-39480 in Secure Integration Server
Summary
by MITRE • 05/03/2024
Softing Secure Integration Server FileDirectory OPC UA Object Arbitrary File Creation Vulnerability. This vulnerability allows remote attackers to create arbitrary files on affected installations of Softing Secure Integration Server. Although authentication is required to exploit this vulnerability, the existing authentication mechanism can be bypassed.
The specific flaw exists within the handling of FileDirectory OPC UA Objects. The issue results from allowing unauthorized access to the filesystem. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of root. Was ZDI-CAN-20549.
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Analysis
by VulDB Data Team • 08/12/2025
The CVE-2023-39480 vulnerability represents a critical arbitrary file creation flaw in Softing Secure Integration Server's OPC UA implementation that undermines the security posture of industrial control systems. This vulnerability specifically targets the FileDirectory OPC UA Object handling mechanism, which is designed to manage file operations within the OPC UA communication framework. The flaw exists in how the system processes file directory operations, allowing attackers to create files at arbitrary locations on the target system's filesystem. The vulnerability's severity is amplified by the fact that while authentication is typically required, the existing authentication mechanisms can be bypassed, making the exploit accessible to remote attackers who may not possess legitimate credentials. This represents a significant compromise in the security model of industrial automation systems where OPC UA serves as a critical communication protocol for supervisory control and data acquisition processes.
The technical implementation of this vulnerability stems from improper input validation and access control within the FileDirectory OPC UA Object processing logic. When the system receives OPC UA requests containing file directory operations, it fails to properly validate the target paths and permissions, allowing attackers to specify arbitrary file system locations for creation. This flaw aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal vulnerabilities. The vulnerability enables attackers to create files in sensitive locations such as system directories, configuration files, or even executable locations that could be leveraged for privilege escalation. The OPC UA protocol's design allows for complex object manipulation, and this particular implementation flaw creates a pathway for attackers to manipulate the file system through legitimate protocol interactions, effectively bypassing normal file system access controls.
The operational impact of CVE-2023-39480 extends beyond simple file creation capabilities and represents a potential pathway to full system compromise within industrial environments. When combined with other vulnerabilities or attack vectors, this flaw could enable attackers to execute arbitrary code with elevated privileges, potentially compromising the entire industrial control system. The vulnerability's exploitation risk is particularly concerning in environments where OPC UA servers serve as communication hubs for critical infrastructure, including manufacturing systems, power grids, and water treatment facilities. Attackers could leverage this vulnerability to establish persistent access, deploy malicious payloads, or manipulate system configurations that could lead to operational disruptions or safety hazards. The attack surface is further expanded by the fact that OPC UA servers often operate in environments with limited network segmentation, making them attractive targets for lateral movement within industrial networks.
Mitigation strategies for CVE-2023-39480 should focus on both immediate patching and operational security enhancements. Organizations must prioritize applying vendor-provided security updates that address the authentication bypass mechanism and strengthen path validation within the FileDirectory OPC UA Object handling code. Network segmentation should be implemented to isolate OPC UA servers from general network traffic, reducing the attack surface for remote exploitation attempts. Access controls should be enforced through robust authentication mechanisms including multi-factor authentication and role-based access controls that limit who can perform file directory operations within the OPC UA framework. Monitoring and logging of OPC UA file operations should be enhanced to detect anomalous file creation patterns that could indicate exploitation attempts. This vulnerability's characteristics align with ATT&CK technique T1078 which covers valid accounts and privilege escalation, making comprehensive audit trails essential for detection. Additionally, implementing principle of least privilege for OPC UA server configurations and regular security assessments of industrial control system protocols will help reduce the risk of similar vulnerabilities being exploited in operational environments.