CVE-2026-2542: Total VPN Path Traversal Vulnerability

CVE-2026-2542 Overview

A local privilege escalation vulnerability has been identified in Total VPN version 0.5.29.0 on Windows systems. The vulnerability exists due to an unquoted service path in the C:\Program Files\Total VPN\win-service.exe executable. This weakness (CWE-426: Untrusted Search Path) allows a local attacker to potentially execute arbitrary code with elevated privileges by placing a malicious executable in a location that Windows will search before the legitimate service binary.

Critical Impact

Local attackers with limited privileges can exploit this unquoted service path vulnerability to achieve privilege escalation, potentially gaining SYSTEM-level access on affected Windows systems running Total VPN.

Affected Products

• Total VPN version 0.5.29.0 on Windows
• Windows systems with Total VPN installed in the default C:\Program Files\Total VPN\ directory

Discovery Timeline

• 2026-02-16 - CVE-2026-2542 published to NVD
• 2026-02-18 - Last updated in NVD database

Technical Details for CVE-2026-2542

Vulnerability Analysis

This vulnerability is classified as an Unquoted Service Path (CWE-426) affecting the Total VPN Windows service. When a Windows service is registered with an executable path that contains spaces but lacks proper quotation marks, Windows parses the path incorrectly during service startup. The operating system attempts to execute files at each space-delimited segment of the path before reaching the intended executable.

In this case, the service path C:\Program Files\Total VPN\win-service.exe contains spaces in both "Program Files" and "Total VPN" directory names. Without quotes around the full path, Windows will attempt to execute:

1. C:\Program.exe
2. C:\Program Files\Total.exe
3. C:\Program Files\Total VPN\win-service.exe

An attacker who can write to any of the earlier locations in this search order can hijack the service execution flow. The attack requires local access and the ability to place a malicious executable in a writable location.

Root Cause

The root cause is improper quoting of the service binary path in the Windows Service Control Manager (SCM) registration. The Total VPN installer failed to wrap the executable path in double quotes, leaving the service vulnerable to search path manipulation. This is a common misconfiguration in Windows service installations where paths containing spaces are not properly escaped.

Attack Vector

The attack vector is local, requiring the attacker to have authenticated access to the target Windows system. The attacker must have write permissions to one of the directories in the search path hierarchy (typically C:\ or C:\Program Files\Total VPN\). Upon system restart or service restart, Windows will execute the attacker's malicious binary with the privileges of the vulnerable service, which typically runs as SYSTEM.

The exploitation is characterized as having high complexity due to the requirement for specific filesystem permissions and timing considerations around service restarts.

Detection Methods for CVE-2026-2542

Indicators of Compromise

• Unexpected executable files named Program.exe in C:\
• Suspicious files named Total.exe in C:\Program Files\
• Unauthorized modifications to the Total VPN installation directory
• Service execution anomalies or unexpected child processes spawned by the Total VPN service

Detection Strategies

• Monitor for file creation events in C:\ for executables with suspicious names like Program.exe
• Audit Windows services for unquoted paths using PowerShell: Get-WmiObject win32_service | Where-Object {$_.PathName -notlike '"*"' -and $_.PathName -like '* *'}
• Implement application whitelisting to prevent unauthorized executables from running
• Deploy endpoint detection and response (EDR) solutions to identify privilege escalation attempts

Monitoring Recommendations

• Enable Windows Security Event logging for process creation (Event ID 4688) with command-line auditing
• Monitor service start/stop events (Event IDs 7036, 7045) for the Total VPN service
• Implement file integrity monitoring on critical system directories
• Configure alerts for new executable files created in root directories or Program Files folders

How to Mitigate CVE-2026-2542

Immediate Actions Required

• Verify if Total VPN version 0.5.29.0 is installed on Windows systems in your environment
• Manually correct the service path by adding quotes around the executable path in the Windows Registry
• Restrict write permissions on C:\ and C:\Program Files\ directories to administrators only
• Consider uninstalling Total VPN until a vendor patch is available, as the vendor did not respond to disclosure attempts

Patch Information

No official patch is currently available from the vendor. According to the vulnerability disclosure, the vendor was contacted but did not respond. Organizations should implement the manual workaround or consider alternative VPN solutions until the vendor addresses this vulnerability. For additional technical details, refer to the GitHub Unquoted Service Path Report and VulDB #346127.

Workarounds

• Manually fix the unquoted service path in the Windows Registry by adding quotes around the ImagePath value
• Remove write permissions for non-administrative users on directories in the search path
• Implement application control policies to block unauthorized executable execution
• Consider using Group Policy to enforce strict software restriction policies

# Registry fix to quote the service path (run as Administrator in PowerShell)
# First, verify the current unquoted path
Get-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Services\TotalVPN" -Name ImagePath

# Update with properly quoted path
Set-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Services\TotalVPN" -Name ImagePath -Value '"C:\Program Files\Total VPN\win-service.exe"'