CVE-2020-8094 in Antivirus Free 2020
Summary
by MITRE • 01/15/2025
An untrusted search path vulnerability in testinitsigs.exe as used in Bitdefender Antivirus Free 2020 allows a low-privilege attacker to execute code as SYSTEM via a specially crafted DLL file.
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Analysis
by VulDB Data Team • 02/08/2025
The vulnerability identified as CVE-2020-8094 represents a critical untrusted search path weakness in the testinitsigs.exe component of Bitdefender Antivirus Free 2020. This flaw exists within the software's privilege escalation mechanism where the executable fails to properly validate the source and integrity of dynamically loaded libraries. The vulnerability stems from the application's improper handling of the Windows search path, which allows an attacker to place a malicious DLL in a location that gets prioritized during the loading process. This particular component operates with elevated privileges during system initialization, creating a pathway for privilege escalation from a low-privilege user account to SYSTEM level access.
The technical exploitation of this vulnerability follows a well-established pattern that aligns with CWE-426 Untrusted Search Path or Working Directory and the broader category of privilege escalation attacks. When testinitsigs.exe executes, it searches for required DLL dependencies in a predictable order that includes user-writable directories, allowing an attacker to place a malicious DLL with the same name as a legitimate dependency. The vulnerability specifically affects the Bitdefender Antivirus Free 2020 product, where the testinitsigs.exe utility is designed to initialize signature files during system startup. This creates a window of opportunity during the boot process when the system is most vulnerable to manipulation. The attack vector requires physical access or the ability to write files to the system, but once successful, it provides complete system compromise.
The operational impact of this vulnerability extends beyond simple code execution to encompass full system compromise and persistent access. An attacker who successfully exploits this vulnerability can execute arbitrary code with SYSTEM privileges, enabling them to install backdoors, modify system files, access sensitive data, and establish persistence mechanisms. This vulnerability is particularly concerning because it operates during system initialization, making it difficult to detect and remediate. The attack can be performed without requiring administrative privileges initially, allowing for stealthy exploitation. The vulnerability affects Windows operating systems where Bitdefender Antivirus Free 2020 is installed, potentially impacting a wide range of endpoints in enterprise environments. The exploitation process aligns with ATT&CK technique T1068, which describes privilege escalation through the use of untrusted search paths, and demonstrates how attackers can leverage legitimate system components to bypass security controls.
Mitigation strategies for CVE-2020-8094 should include immediate patching of the affected Bitdefender Antivirus Free 2020 version, as well as implementing additional security controls to prevent DLL hijacking. Organizations should ensure that all system components are kept up to date with the latest security patches from vendors. Network segmentation and access controls can help limit the potential impact of such vulnerabilities by reducing the attack surface. The principle of least privilege should be enforced, ensuring that applications run with minimal required permissions. System administrators should monitor for unusual DLL loading patterns and implement application whitelisting to prevent unauthorized code execution. Additionally, regular security audits should verify that no malicious DLLs have been placed in system directories. The vulnerability highlights the importance of secure coding practices and proper validation of library loading paths, which are fundamental requirements in secure software development lifecycle processes.