CVE-2015-7917 in OPC Systems.NET
Summary
by MITRE
Untrusted search path vulnerability in Open Automation OPC Systems.NET 8.00.0023 and earlier allows local users to gain privileges via a Trojan horse DLL in an unspecified directory.
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Analysis
by VulDB Data Team • 05/20/2018
The vulnerability identified as CVE-2015-7917 represents a critical untrusted search path issue within Open Automation OPC Systems.NET version 8.00.0023 and earlier implementations. This flaw resides in the application's dynamic link library loading mechanism where the software fails to properly validate the source and authenticity of dynamically loaded modules. The vulnerability stems from the application's tendency to search for required DLL files in a predictable sequence of directories without adequate security controls to prevent malicious code injection. Attackers can exploit this weakness by placing a malicious DLL file in a directory that gets searched before the legitimate application directories, thereby enabling privilege escalation through the execution of unauthorized code with elevated privileges.
This vulnerability directly maps to CWE-426, which describes the insecure loading of dynamic libraries, and aligns with ATT&CK technique T1059.001 for command and scripting interpreter usage. The issue manifests when the application executes with elevated privileges and attempts to load DLL dependencies, creating a window where an attacker can manipulate the search path to load malicious code instead of the intended legitimate libraries. The unspecified directory mentioned in the vulnerability description indicates that the attack vector can occur in multiple locations within the system's file hierarchy, making detection and prevention more challenging for security administrators. The local nature of this vulnerability means that exploitation requires physical access or pre-existing low-privilege access to the target system, but the successful exploitation results in privilege escalation to the level of the target application.
The operational impact of CVE-2015-7917 extends beyond simple code execution, as it fundamentally undermines the integrity of the application's dependency resolution process. When exploited, this vulnerability allows attackers to execute arbitrary code with the privileges of the target application, potentially leading to complete system compromise if the application runs with administrative rights. The attack requires minimal sophistication but can result in significant damage to industrial control systems and automation environments where Open Automation OPC Systems.NET is deployed. Organizations using this software face potential data exfiltration, system corruption, and unauthorized access to critical infrastructure components. The vulnerability's persistence across multiple versions indicates a systemic design flaw that was not adequately addressed in the software's development lifecycle.
Mitigation strategies for CVE-2015-7917 should focus on implementing proper DLL loading security measures and enforcing strict path validation. System administrators should immediately upgrade to versions of Open Automation OPC Systems.NET that address this vulnerability, as no reliable workarounds exist for the affected versions. The implementation of Windows Defender Application Control or similar application whitelisting solutions can prevent execution of unauthorized DLL files regardless of their location in the search path. Additionally, the principle of least privilege should be enforced by running applications with minimal required permissions and ensuring that the application's search path is properly configured to prioritize secure directories. Regular security audits should verify that no malicious DLL files exist in directories that are part of the application's search path, and system monitoring should be implemented to detect unusual file access patterns that might indicate exploitation attempts. Organizations should also consider implementing intrusion detection systems that can identify potential exploitation attempts targeting this specific vulnerability pattern.