CVE-2017-11159 in Photo Station Uploader
Summary
by MITRE
Multiple untrusted search path vulnerabilities in installer in Synology Photo Station Uploader before 1.4.2-084 on Windows allows local attackers to execute arbitrary code and conduct DLL hijacking attack via a Trojan horse (1) shfolder.dll, (2) ntmarta.dll, (3) secur32.dll or (4) dwmapi.dll file in the current working directory.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 12/16/2022
The vulnerability identified as CVE-2017-11159 represents a critical untrusted search path issue affecting the Synology Photo Station Uploader installer on Windows systems. This flaw exists within the installer component of the software and affects versions prior to 1.4.2-084, creating a significant security risk for local attackers who can exploit this weakness to execute arbitrary code. The vulnerability stems from the installer's improper handling of dynamic link library (dll) loading mechanisms, which fail to properly validate or restrict the search paths used when loading required system libraries.
The technical implementation of this vulnerability involves four specific dll files that can be exploited through a Trojan horse attack vector: shfolder.dll, ntmarta.dll, secur32.dll, and dwmapi.dll. These dll files are commonly found in legitimate system directories, making them ideal candidates for hijacking attacks. When the vulnerable installer runs, it searches for these libraries in the current working directory before checking standard system paths, creating an opportunity for malicious actors to place crafted dll files in the same directory as the installer. This behavior aligns with CWE-426, which describes untrusted search path vulnerabilities where applications search for libraries in insecure locations, and represents a classic example of DLL hijacking as documented in the MITRE ATT&CK framework under the technique of DLL hijacking.
The operational impact of this vulnerability is substantial as it allows local attackers with minimal privileges to execute arbitrary code on affected systems. This creates a privilege escalation vector that can be leveraged to gain unauthorized access to system resources, potentially leading to full system compromise. Attackers can exploit this vulnerability by simply placing malicious versions of the targeted dll files in the directory where the installer is executed, without requiring administrative privileges or complex attack chains. The vulnerability is particularly concerning because it affects the installation process itself, meaning that any user who runs the vulnerable installer could be compromised, regardless of their security awareness or system protections.
Mitigation strategies for this vulnerability include immediate upgrading to Synology Photo Station Uploader version 1.4.2-084 or later, which addresses the untrusted search path issue through proper dll loading mechanisms. System administrators should also implement strict file permissions and access controls to limit the ability of unauthorized users to place malicious files in directories where legitimate installers might execute. Additionally, network segmentation and application whitelisting can help prevent exploitation by ensuring that only trusted software can execute on affected systems. The vulnerability demonstrates the importance of secure coding practices and proper library loading mechanisms, particularly in installer components where elevated privileges may be required. Organizations should also consider implementing monitoring solutions to detect suspicious dll loading activities and maintain up-to-date vulnerability assessments to identify similar issues in other software components. This vulnerability serves as a reminder of the critical nature of secure development practices and the potential consequences of improper path resolution in system installation processes.