CVE-2012-3015 in SIMATIC PCS7
Summary
by MITRE
Untrusted search path vulnerability in Siemens SIMATIC STEP7 before 5.5 SP1, as used in SIMATIC PCS7 7.1 SP3 and earlier and other products, allows local users to gain privileges via a Trojan horse DLL in a STEP7 project folder.
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Analysis
by VulDB Data Team • 07/15/2024
The vulnerability identified as CVE-2012-3015 represents a critical untrusted search path issue affecting Siemens SIMATIC STEP7 software and related industrial control systems. This flaw exists within the software's dynamic link library loading mechanism, where the application fails to properly validate or sanitize the search paths used to locate required DLL files. The vulnerability specifically impacts Siemens SIMATIC STEP7 versions prior to 5.5 SP1 and affects SIMATIC PCS7 7.1 SP3 and earlier versions, creating a significant security risk for industrial automation environments.
The technical implementation of this vulnerability stems from the software's improper handling of DLL search order mechanisms. When STEP7 processes project files, it traverses specific directories to locate necessary dynamic link libraries for execution. Attackers can exploit this behavior by placing malicious Trojan horse DLL files within the STEP7 project folder structure, which the software will load and execute with the privileges of the currently logged-in user. This privilege escalation occurs because the software does not implement proper path validation or use of secure loading mechanisms that would prevent loading of DLLs from untrusted locations. The flaw operates at the operating system level where the LoadLibrary function is used without proper security context enforcement.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with a potential pathway for persistent access within industrial control systems. Local users with access to the STEP7 environment can leverage this vulnerability to execute arbitrary code with elevated privileges, potentially compromising the integrity of industrial processes. The attack vector is particularly concerning in industrial settings where operators may have legitimate access to these systems but could be coerced or compromised to install malicious code. This vulnerability can lead to unauthorized process modifications, data manipulation, or even system disruption in critical infrastructure environments. The exploitability is relatively straightforward, requiring only local access to the system and knowledge of the software's directory structure.
Mitigation strategies for CVE-2012-3015 should focus on both immediate remediation and long-term security hardening measures. The primary recommendation is to upgrade to Siemens SIMATIC STEP7 5.5 SP1 or later versions where the vulnerability has been addressed through proper DLL loading mechanisms and enhanced search path validation. Organizations should also implement strict access controls and privilege separation within industrial environments, ensuring that only authorized personnel have access to development and configuration tools. Additionally, implementing application whitelisting policies and using secure coding practices that enforce proper DLL loading sequences can prevent similar vulnerabilities from manifesting in other applications. This vulnerability aligns with CWE-427 Uncontrolled Search Path Element and represents a common weakness in industrial software security that requires systematic approach to address through both vendor patches and operational security measures. The attack pattern follows typical privilege escalation techniques documented in the ATT&CK framework under privilege escalation tactics, specifically focusing on the use of trusted system components for malicious purposes.