CVE-2016-20085 in High Definition Audio Driver
Summary
by MITRE • 06/19/2026
Realtek High Definition Audio Driver 6.0.1.6730 contains an unquoted service path vulnerability that allows local attackers to escalate privileges by placing a malicious executable in the service path. Attackers can insert an executable file in the unquoted path and restart the service to execute code with LocalSystem privileges.
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Analysis
by VulDB Data Team • 06/19/2026
The Realtek High Definition Audio Driver version 6.0.1.6730 presents a critical privilege escalation vulnerability through an unquoted service path configuration that directly violates security best practices outlined in cwe-428. This vulnerability exists within the Windows service installation where the service path contains spaces but lacks proper quotation around the entire path specification. The affected service utilizes a path such as c:program filesrealtekaudio driverhdadriver.exe without proper quoting which creates a predictable attack surface for local adversaries seeking elevated privileges. The flaw stems from the Windows service architecture where the operating system resolves paths by searching through each directory component in sequence until it finds an executable with the same name as the service, allowing attackers to place malicious binaries in parent directories of the service path. This vulnerability operates under the attack pattern described in the attack tactic of privilege escalation and specifically aligns with the technique of service binary path manipulation as documented in the attack framework. The operational impact of this vulnerability is severe as it enables local attackers with standard user privileges to execute arbitrary code with the highest system privileges, effectively bypassing standard access controls and user account control mechanisms. When an attacker places a malicious executable with the same name as a directory component in the service path, the system will execute this malicious binary instead of the legitimate service executable upon service restart or system reboot. The vulnerability directly enables the execution of malicious code with local system privileges, providing attackers with complete control over the affected system and potentially enabling further lateral movement within network environments.
The technical implementation of this vulnerability relies on the Windows service management system's path resolution behavior where unquoted paths are interpreted as multiple directory components rather than a single path. This creates a race condition where an attacker can place an executable file in a directory that appears in the service path before the legitimate service executable is executed. The service path typically follows the format c:program filesrealtekaudio driverhdadriver.exe where the space between program files and realtek creates a parsing opportunity for attackers. According to cwe-428, this represents a classic case of unquoted service path vulnerability where the service configuration does not properly quote the path, creating a security weakness that allows for privilege escalation. The attack vector requires local system access and knowledge of the specific service path, but the execution of malicious code occurs with elevated privileges, making this particularly dangerous. The vulnerability affects systems where the Realtek audio driver is installed with default settings, which is common across many consumer and enterprise deployments. The service restart or system reboot triggers the execution of the malicious binary, allowing attackers to establish persistence and maintain elevated access to the compromised system. This issue particularly affects the attack phase of privilege escalation in the attack chain and demonstrates the importance of proper service path configuration as outlined in secure coding practices and security guidelines.
Mitigation strategies for this vulnerability require immediate patching of the Realtek audio driver to the latest version that properly quotes service paths and implements secure service configurations. System administrators should conduct comprehensive audits of installed services to identify other unquoted paths that may present similar vulnerabilities, as this represents a common security misconfiguration pattern. The recommended approach includes implementing the principle of least privilege for service accounts and ensuring that all service paths are properly quoted to prevent path resolution attacks. Additionally, regular security scanning should include verification of service path configurations, particularly for third-party software installations. Organizations should also implement application whitelisting policies to prevent execution of unauthorized binaries in system directories, and maintain regular updates of audio drivers and other system components to address known vulnerabilities. The vulnerability highlights the importance of secure service installation practices and the need for security awareness regarding service configuration management. System hardening procedures should include verification that all service paths are properly quoted and that no directory components in the path contain spaces without proper quotation. The attack scenario demonstrates how seemingly minor configuration issues can lead to significant security implications, emphasizing the need for comprehensive security reviews of system components and their installation parameters. Regular monitoring and auditing of service configurations can help identify and remediate similar vulnerabilities before they can be exploited by malicious actors.