CVE-2019-25287: Adaware Web Companion Privilege Escalation

CVE-2019-25287 Overview

CVE-2019-25287 is a high-severity unquoted service path vulnerability affecting Adaware Web Companion version 4.8.2078.3950. The vulnerability exists in the WCAssistantService component, which contains an improperly quoted service executable path. This flaw allows local users to potentially execute arbitrary code with elevated privileges by exploiting the unquoted path structure.

When Windows attempts to start the service, it parses the unquoted path C:\Program Files (x86)\Lavasoft\Web Companion\Application\ and may inadvertently execute a malicious binary placed in a path that Windows interprets before reaching the legitimate executable. This can result in code execution with LocalSystem privileges during service startup.

Critical Impact

Local attackers can achieve privilege escalation to LocalSystem by exploiting the unquoted service path in WCAssistantService, potentially gaining complete control over the affected system.

Affected Products

• Adaware Web Companion version 4.8.2078.3950
• WCAssistantService component

Discovery Timeline

• 2026-02-05 - CVE-2019-25287 published to NVD
• 2026-02-05 - Last updated in NVD database

Technical Details for CVE-2019-25287

Vulnerability Analysis

This vulnerability falls under CWE-428 (Unquoted Search Path or Element), a common Windows service misconfiguration that can lead to privilege escalation. The root issue lies in how the WCAssistantService registers its executable path in the Windows Service Control Manager without proper quotation marks.

When a service path contains spaces and is not enclosed in quotes, Windows uses a specific algorithm to locate the executable. For the path C:\Program Files (x86)\Lavasoft\Web Companion\Application\, Windows will attempt to execute files in the following order:

1. C:\Program.exe
2. C:\Program Files.exe
3. C:\Program Files (x86)\Lavasoft\Web.exe
4. C:\Program Files (x86)\Lavasoft\Web Companion\Application\[actual executable]

An attacker with local access and write permissions to any of these intermediate paths can place a malicious executable that will be run instead of the legitimate service binary, inheriting the service's LocalSystem privileges.

Root Cause

The vulnerability stems from improper service registration during the Adaware Web Companion installation process. The installer fails to wrap the service executable path in quotation marks when registering the WCAssistantService with the Windows Service Control Manager. This is a common oversight in software installers that deploy services to paths containing spaces.

Attack Vector

The attack requires local access to the system. An attacker must have write permissions to one of the intermediate directories that Windows will check when resolving the unquoted path. In many Windows configurations, low-privileged users may have write access to the root of C:\, allowing them to create a malicious Program.exe file. When the vulnerable service starts (either manually, at system boot, or upon service restart), the malicious executable runs with LocalSystem privileges—the highest privilege level on a Windows system.

The exploitation mechanism relies on Windows path resolution behavior with unquoted paths containing spaces. When the service starts, the attacker-controlled executable inherits the LocalSystem security context of the WCAssistantService, enabling full system compromise.

Detection Methods for CVE-2019-25287

Indicators of Compromise

• Unexpected executables named Program.exe, Web.exe, or similar in the C:\, C:\Program Files (x86)\, or C:\Program Files (x86)\Lavasoft\ directories
• Suspicious process creation events where parent process is services.exe but child is not the legitimate Web Companion executable
• New files created in system directories that match Windows path resolution patterns for unquoted service paths
• Anomalous service startup behavior or failures for WCAssistantService

Detection Strategies

• Query the Windows registry or use sc qc WCAssistantService to verify if the service path is properly quoted
• Implement file integrity monitoring on directories that could be targeted by unquoted path exploitation
• Monitor for process creation events where executables in root directories spawn with SYSTEM privileges
• Use endpoint detection tools to identify binaries that do not match expected software signatures in service-related paths

Monitoring Recommendations

• Enable Windows Security Event logging for service control events (Event ID 7045) and process creation (Event ID 4688)
• Configure SentinelOne's behavioral AI to detect suspicious privilege escalation patterns associated with service exploitation
• Implement application whitelisting to prevent unauthorized executables from running in service paths
• Regularly audit installed services for unquoted path vulnerabilities using tools like PowerSploit's Get-UnquotedService module

How to Mitigate CVE-2019-25287

Immediate Actions Required

• Verify if Adaware Web Companion is installed on systems and identify the installed version
• Manually correct the service path by enclosing it in quotation marks using the Windows Registry Editor or sc config command
• Restrict write permissions on directories in the service path to prevent malicious binary placement
• Consider uninstalling Adaware Web Companion if it is not essential for business operations

Patch Information

Users should check the Web Companion official site for updated versions that address this vulnerability. Additional technical details are available in the Exploit-DB #47597 entry and the VulnCheck Advisory for Adaware.

Workarounds

• Manually fix the unquoted service path by modifying the ImagePath registry value under HKLM\SYSTEM\CurrentControlSet\Services\WCAssistantService
• Remove write permissions from intermediate directories in the service path for non-administrative users
• Implement application control policies to prevent execution of unsigned binaries in system directories
• If the software is not critical, consider removing Adaware Web Companion entirely until an official patch is available

# Fix unquoted service path via command line
sc config "WCAssistantService" binPath= "\"C:\Program Files (x86)\Lavasoft\Web Companion\Application\WCAssistantService.exe\""