CVE-2019-19929 in AdwCleaner
Summary
by MITRE
An Untrusted Search Path vulnerability in Malwarebytes AdwCleaner before 8.0.1 could cause arbitrary code execution with SYSTEM privileges when a malicious DLL library is loaded by the product.
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Analysis
by VulDB Data Team • 03/16/2024
The vulnerability identified as CVE-2019-19929 represents a critical untrusted search path issue within Malwarebytes AdwCleaner software prior to version 8.0.1. This flaw resides in the application's dynamic link library loading mechanism, where the software fails to properly validate the source and integrity of dynamically loaded modules. The vulnerability stems from the application's insecure handling of the Windows search path, allowing malicious actors to place specially crafted DLL files in directories that are prioritized during the loading process. This insecure practice directly violates the principle of least privilege and creates a dangerous attack surface that can be exploited to escalate privileges to SYSTEM level access. The issue is classified under CWE-427, which specifically addresses uncontrolled search path dependencies, making it a well-documented and serious security weakness in software development practices.
The technical exploitation of this vulnerability occurs when a malicious actor places a crafted DLL file in a directory that AdwCleaner will search before the legitimate system directories. When the application executes and attempts to load required libraries, it inadvertently loads the malicious DLL instead of the intended legitimate module. This behavior enables arbitrary code execution with elevated privileges since AdwCleaner runs with SYSTEM permissions during its operation. The attack vector leverages the Windows DLL search order mechanism, where the system first searches the current working directory, followed by system directories, and then the PATH environment variable. This vulnerability is particularly dangerous because it can be triggered through various means including social engineering, compromised installation media, or manipulation of the application's execution environment. The flaw represents a classic privilege escalation vulnerability that aligns with ATT&CK technique T1068, which covers local privilege escalation through exploitation of software vulnerabilities.
The operational impact of CVE-2019-19929 extends beyond simple code execution to encompass full system compromise capabilities. When successfully exploited, adversaries gain SYSTEM-level access to affected systems, enabling them to install persistent backdoors, exfiltrate sensitive data, modify system configurations, and establish covert command and control channels. The vulnerability affects organizations that rely on Malwarebytes AdwCleaner for malware removal and system protection, creating a paradox where the security tool becomes a vector for system compromise. This issue particularly impacts enterprise environments where the software is deployed across multiple endpoints, potentially allowing attackers to gain a foothold in networks through a single vulnerable installation. The vulnerability's exploitation requires minimal technical skill and can be automated, making it attractive to both sophisticated and less experienced threat actors. Organizations with outdated AdwCleaner installations face significant risk of persistent malware infections and data breaches, as the malicious DLL execution occurs with elevated privileges that bypass standard user access controls.
Mitigation strategies for CVE-2019-19929 focus on both immediate remediation and long-term security hardening. The most effective immediate solution is upgrading to Malwarebytes AdwCleaner version 8.0.1 or later, which addresses the untrusted search path vulnerability through proper DLL loading mechanisms. Organizations should implement application whitelisting policies to prevent unauthorized DLL execution and configure the Windows search path to prioritize system directories over user-controlled locations. Security administrators should monitor for signs of exploitation including unusual process creation patterns, unexpected DLL loads, and anomalous network connections. Additional protective measures include regular system audits to identify vulnerable installations, implementation of endpoint detection and response solutions to monitor for suspicious DLL loading activities, and maintaining updated threat intelligence feeds to detect exploitation attempts. The vulnerability highlights the importance of secure coding practices including proper DLL loading validation and adherence to security standards such as those outlined in the OWASP Top Ten and NIST Cybersecurity Framework, which emphasize the need for secure software development lifecycle practices to prevent such vulnerabilities from occurring in the first place.