CVE-2016-7165 in SIMATIC NET PC-Software
Summary
by MITRE
Unquoted Windows search path vulnerability in Siemens SIMATIC WinCC before 7.0 SP2 Upd 12, 7.0 SP3 before Upd 8, and 7.2 through 7.4; SIMATIC WinCC (TIA Portal) Basic, Comfort, Advanced before 14; SIMATIC WinCC Runtime Professional; SIMATIC WinCC (TIA Portal) Professional; SIMATIC STEP 7 5.x; SIMATIC STEP 7 (TIA Portal) before 14; SIMATIC NET PC-Software before 14; TeleControl Server Basic before 3.0 SP2; SINEMA Server before 13 SP2; SIMATIC PCS 7 through 8.2; SINEMA Remote Connect Client; SIMATIC WinAC RTX 2010 SP2; SIMATIC WinAC RTX F 2010 SP2; SIMATIC IT Production Suite; SOFTNET Security Client 5.0; SIMIT 9.0; Security Configuration Tool (SCT); and Primary Setup Tool (PST), when the installation does not use the %PROGRAMFILES% directory, might allow local users to gain privileges via a Trojan horse executable file.
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Analysis
by VulDB Data Team • 06/01/2019
This vulnerability represents a classic unquoted search path weakness that affects multiple Siemens industrial automation and control software products. The flaw occurs when installation directories are not placed within the standard %PROGRAMFILES% directory structure, creating opportunities for privilege escalation through malicious Trojan horse executables. The vulnerability is particularly concerning in industrial control systems where maintaining system integrity and preventing unauthorized access is critical for operational security.
The technical implementation of this vulnerability stems from how Windows resolves executable paths when searching for applications. When a software installation path contains spaces and is not properly quoted in the system PATH environment variable or registry entries, Windows may interpret the path incorrectly. Attackers can exploit this by placing malicious executables in directories that are searched before the legitimate application directories, allowing them to execute code with the privileges of the targeted application. This follows the established CWE-428 weakness pattern for unquoted search paths in Windows environments.
The operational impact of CVE-2016-7165 extends beyond simple privilege escalation to potentially compromise entire industrial control systems. In the context of Siemens products, this vulnerability could allow local attackers to gain elevated privileges on systems running WinCC, STEP 7, PCS 7, or other industrial software components. The attack vector is particularly dangerous because it requires minimal privileges to exploit, making it accessible to any local user who can place files on the system. This aligns with ATT&CK technique T1068 for local privilege escalation and represents a significant risk to industrial cybersecurity frameworks.
Mitigation strategies for this vulnerability must address both the immediate installation configuration issues and broader system hardening practices. Organizations should ensure all software installations use the standard %PROGRAMFILES% directory structure, properly quote all installation paths in system configuration, and implement strict access controls on system directories. Regular security assessments should verify that no unquoted paths exist in system configurations, and system administrators should monitor for unauthorized file placements in common search directories. The vulnerability demonstrates the importance of following secure coding practices and proper system configuration management, which aligns with NIST SP 800-80 guidelines for industrial control system security. Additionally, implementing application whitelisting solutions and maintaining up-to-date system patches can provide additional layers of protection against exploitation attempts.