CVE-2019-5957 in Electronic Reception
Summary
by MITRE
Untrusted search path vulnerability in Installer of Electronic reception and examination of application for radio licenses Online 1.0.9.0 and earlier allows an attacker to gain privileges via a Trojan horse DLL in an unspecified directory.
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Analysis
by VulDB Data Team • 09/23/2023
The vulnerability identified as CVE-2019-5957 represents a critical untrusted search path issue within the Installer component of the Electronic reception and examination of application for radio licenses Online software version 1.0.9.0 and earlier. This flaw resides in the installer's dynamic link library loading mechanism, which fails to properly validate or sanitize the search paths used when loading required system components. The vulnerability specifically affects the software's ability to securely resolve and load DLL files during installation processes, creating a potential attack surface that adversaries can exploit to execute malicious code with elevated privileges. The issue stems from the installer's reliance on a predictable search order that includes user-writable directories, allowing attackers to place malicious DLL files in locations where the installer will automatically load them without proper validation.
This vulnerability directly maps to CWE-426, which describes the Untrusted Search Path weakness where programs execute code from untrusted or user-controllable locations. The operational impact of this flaw is significant as it enables privilege escalation attacks through a Trojan horse DLL technique where an attacker places a malicious library in a directory that gets searched by the installer process. The attack vector exploits the inherent trust placed in the installation process, allowing adversaries to inject malicious code that executes with the privileges of the installer, potentially leading to full system compromise. The vulnerability's severity is amplified by the fact that it occurs during the installation phase when the system is typically running with elevated privileges, making successful exploitation particularly dangerous for the target environment.
The attack scenario begins with an attacker identifying a writable directory within the installer's search path, typically a location in the user's home directory or a shared folder that gets automatically included in the system's PATH environment variable. The attacker then places a malicious DLL file with the same name as a legitimate system library that the installer expects to load, effectively creating a Trojan horse attack. When the installer executes and attempts to load the expected library, it inadvertently loads the attacker's malicious DLL instead, executing arbitrary code with the privileges of the installer process. This technique leverages the principle of least privilege violation and demonstrates how seemingly benign installation processes can become attack vectors when proper input validation and secure coding practices are not implemented. The vulnerability's exploitation aligns with ATT&CK technique T1059.001 for executing malicious code and T1068 for privilege escalation through trusted installation processes.
Mitigation strategies for this vulnerability should focus on implementing secure coding practices during the development lifecycle, including the use of absolute paths for DLL loading, proper input validation, and the implementation of secure search path mechanisms. Organizations should immediately update to the latest version of the software where this vulnerability has been patched, as the vendor has likely implemented proper DLL loading security measures. System administrators should conduct thorough security assessments of the affected software installations and monitor for any suspicious activity that might indicate exploitation attempts. The implementation of application whitelisting solutions and the enforcement of least privilege principles for installation processes can significantly reduce the risk of exploitation. Additionally, regular security audits of installation processes and the use of tools that monitor for unauthorized DLL loading activities can help detect and prevent exploitation attempts before they succeed in compromising the system.