CVE-2015-1594 in SIMATIC Prosave
Summary
by MITRE
Untrusted search path vulnerability in Siemens SIMATIC ProSave before 13 SP1; SIMATIC CFC before 8.0 SP4 Upd9 and 8.1 before Upd1; SIMATIC STEP 7 before 5.5 SP1 HF2, 5.5 SP2 before HF7, 5.5 SP3, and 5.5 SP4 before HF4; SIMOTION Scout before 4.4; and STARTER before 4.4 HF3 allows local users to gain privileges via a Trojan horse application file.
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Analysis
by VulDB Data Team • 05/01/2022
The vulnerability identified as CVE-2015-1594 represents a critical untrusted search path issue affecting multiple Siemens industrial automation software products including SIMATIC ProSave, CFC, STEP 7, SIMOTION Scout, and STARTER. This flaw stems from improper handling of application search paths during software execution, creating opportunities for privilege escalation through malicious Trojan horse application files. The vulnerability specifically affects versions prior to the mentioned service packs and updates, indicating a widespread issue across Siemens' industrial control software ecosystem. The untrusted search path vulnerability allows attackers to manipulate the software's execution environment by placing malicious binaries in directories that are searched before legitimate application directories, effectively enabling code injection attacks.
The technical exploitation of this vulnerability occurs when local users leverage the software's default search behavior to execute malicious code with elevated privileges. The flaw manifests in how these industrial automation applications resolve file paths during execution, particularly when searching for required libraries or helper applications. When the software searches through directories in an insecure order, attackers can place malicious executables with the same names as legitimate applications in earlier search path locations. This creates a privilege escalation scenario where a local user can execute arbitrary code with the privileges of the target application, potentially leading to system compromise and disruption of industrial processes. The vulnerability aligns with CWE-426 Untrusted Search Path, which specifically addresses the security implications of insecure path resolution mechanisms. This weakness is particularly dangerous in industrial environments where software applications often run with elevated privileges to perform critical control functions.
The operational impact of CVE-2015-1594 extends beyond simple privilege escalation to potentially compromise entire industrial control systems. In industrial automation environments, the affected software components often serve as critical control interfaces or configuration tools that may run with administrative privileges. Successful exploitation could allow attackers to modify control parameters, disrupt production processes, or gain access to sensitive operational data. The vulnerability is particularly concerning in environments where physical security measures are insufficient, as local access often represents a significant threat vector. The attack scenario typically involves placing a malicious Trojan horse file in a directory that will be searched before legitimate application directories, then executing the target software to trigger the malicious code execution. This type of attack falls under ATT&CK technique T1059 Command and Scripting Interpreter, specifically targeting local execution paths to achieve system compromise. The potential for disruption in industrial settings makes this vulnerability particularly dangerous as it could impact safety-critical processes.
Mitigation strategies for CVE-2015-1594 require immediate implementation of software updates and patches provided by Siemens to address the untrusted search path vulnerability. Organizations should prioritize updating all affected Siemens software versions to their latest service packs and cumulative updates. Additionally, system administrators should implement proper access controls and privilege separation to limit local user access to critical industrial applications. Network segmentation and monitoring should be enhanced to detect suspicious file placement activities in application directories. The implementation of application whitelisting solutions can help prevent execution of unauthorized binaries, while regular security audits should verify that search paths are properly configured without insecure directory precedence. System hardening measures including disabling unnecessary services and implementing secure configuration baselines for industrial control systems should be deployed. Organizations should also consider implementing behavioral monitoring solutions to detect anomalous execution patterns that might indicate exploitation attempts, as these vulnerabilities often require specific environmental conditions to be successfully exploited in industrial settings.