CVE-2016-20059 in Malware Fighter
Summary
by MITRE • 04/04/2026
IObit Malware Fighter 4.3.1 contains an unquoted service path vulnerability in the IMFservice and LiveUpdateSvc services that allows local attackers to escalate privileges. Attackers can insert a malicious executable file in the unquoted service path and trigger privilege escalation when the service restarts or the system reboots, executing code with LocalSystem privileges.
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Analysis
by VulDB Data Team • 04/04/2026
The vulnerability identified as CVE-2016-20059 represents a critical privilege escalation flaw within IObit Malware Fighter version 4.3.1, specifically affecting the IMFservice and LiveUpdateSvc services. This issue stems from improper service path configuration where the executable paths are not properly quoted, creating a dangerous condition that adversaries can exploit to execute malicious code with elevated privileges. The vulnerability resides in the Windows service architecture and demonstrates a fundamental flaw in how service paths are configured, making it accessible to local attackers who possess minimal privileges.
The technical implementation of this vulnerability involves the manipulation of Windows service execution paths that lack proper quotation around directory names containing spaces. When Windows attempts to execute a service, it searches for executables in the specified path and continues searching through parent directories if the exact path is not quoted. This behavior creates opportunities for attackers to place malicious executables in directories that are searched before the legitimate service executable, effectively hijacking the service execution flow. The vulnerability specifically affects the IMFservice and LiveUpdateSvc services, which run with LocalSystem privileges, making successful exploitation particularly dangerous as it can lead to complete system compromise.
From an operational perspective, this vulnerability enables local attackers to achieve privilege escalation without requiring administrative credentials or complex attack vectors. The exploit requires only that an attacker can write to a directory within the service path, which is often possible in user-accessible locations. When the affected services restart or the system reboots, the malicious executable located in the unquoted path gets executed with the privileges of the LocalSystem account, providing attackers with full system control. This makes the vulnerability particularly attractive to attackers seeking persistent access and system-wide compromise, as the exploitation process is relatively straightforward and reliable.
The vulnerability aligns with CWE-428, which describes the weakness of unquoted service paths, and represents a common pattern in Windows service misconfigurations that fall under the ATT&CK technique T1059.001 for command and scripting interpreter. Security professionals should implement immediate mitigations including proper quoting of service paths, regular service path audits, and privilege separation measures. Organizations should also consider implementing application whitelisting policies and monitoring for suspicious service execution patterns. The recommended remediation involves updating to a patched version of IObit Malware Fighter or reconfiguring the service paths to ensure all directory names are properly quoted, preventing the Windows service manager from performing unintended path searches that could lead to code execution by unauthorized parties.
This vulnerability demonstrates the critical importance of proper service configuration and path management in Windows environments. The flaw represents a classic example of how seemingly minor configuration issues can create significant security risks, particularly when services execute with elevated privileges. The attack vector is particularly concerning because it requires minimal privileges to exploit and can be automated through system restarts or service restarts, making it a persistent threat that can be leveraged for extended access without detection. The vulnerability also highlights the need for comprehensive security testing of third-party applications, particularly security tools that run with elevated privileges, as these applications often become primary targets for attackers seeking to escalate privileges and gain persistent access to systems.