CVE-2020-37037 in SecureLine
Summary
by MITRE • 02/01/2026
Avast SecureLine 5.5.522.0 contains an unquoted service path vulnerability that allows local users to potentially execute code with elevated system privileges. Attackers can exploit the unquoted path in the service configuration to inject malicious code that would execute with LocalSystem account permissions during service startup.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 02/02/2026
The vulnerability identified as CVE-2020-37037 resides within Avast SecureLine version 5.5.522.0 and represents a critical security flaw that exploits an unquoted service path configuration. This issue falls under the broader category of service path vulnerabilities that have been extensively documented in cybersecurity frameworks including CWE-428 which specifically addresses "Unquoted Service Path" weaknesses. The vulnerability manifests when the Windows service configuration contains a path to an executable that is not enclosed in quotation marks, creating a potential attack vector for privilege escalation.
The technical exploitation of this vulnerability occurs through a well-documented attack pattern that aligns with ATT&CK technique T1035 for "Service Execution" and T1068 for "Exploitation for Privilege Escalation". When Windows attempts to start the vulnerable service, it follows a specific search order that can be manipulated by attackers. If the service path contains spaces and lacks proper quotation, Windows will first search for executables in the root directory of the drive, then proceed through the full path. This behavior allows attackers to place malicious executables in directories that Windows searches before the intended target location, effectively hijacking the service execution flow.
The operational impact of this vulnerability extends beyond simple code execution as it enables local users to gain elevated privileges through the LocalSystem account permissions. This privilege escalation occurs automatically during service startup without requiring additional user interaction or authentication, making the attack particularly dangerous in environments where local access is possible. The vulnerability essentially provides a persistent backdoor mechanism that can be exploited by any local user with the ability to modify service configurations, which in many enterprise environments includes users with standard privileges due to inadequate access controls.
Security professionals should note that this vulnerability is particularly concerning because it operates at the system level and requires minimal prerequisites for exploitation. The attack vector is straightforward and reliable, making it attractive to both malicious actors and red teams conducting penetration testing. The unquoted service path vulnerability has been recognized by multiple cybersecurity organizations as a common misconfiguration that can lead to significant security breaches, with similar patterns observed in numerous other software products across different vendors and platforms.
Mitigation strategies for CVE-2020-37037 should focus on immediate service path remediation through proper quotation of executable paths in service configurations. Organizations should implement comprehensive service configuration audits to identify and correct all unquoted service paths across their infrastructure. The recommended approach involves using the Windows service control manager to reconfigure affected services with properly quoted paths, ensuring that the complete path to executable files includes quotation marks. Additionally, implementing least privilege principles and regular security assessments can help prevent exploitation attempts. System administrators should also consider deploying automated monitoring solutions that can detect anomalous service behavior or unauthorized modifications to service configurations, providing early warning capabilities for potential exploitation attempts.