CVE-2019-25308: Mikogo Privilege Escalation Vulnerability

CVE-2019-25308 Overview

CVE-2019-25308 is an unquoted service path vulnerability affecting Mikogo version 5.2.2.150317. The Mikogo-Service Windows service is configured with an unquoted path containing spaces, allowing local attackers to escalate privileges by placing malicious executables in strategic file system locations. Successful exploitation grants the attacker LocalSystem privileges, the highest privilege level on Windows systems.

Critical Impact

Local privilege escalation to LocalSystem allows complete system compromise, including access to all files, registry keys, and the ability to install persistent malware or create backdoor accounts.

Affected Products

• Mikogo 5.2.2.150317
• Mikogo-Service Windows service component

Discovery Timeline

• 2026-02-11 - CVE CVE-2019-25308 published to NVD
• 2026-02-11 - Last updated in NVD database

Technical Details for CVE-2019-25308

Vulnerability Analysis

This vulnerability stems from CWE-428: Unquoted Search Path or Element. When a Windows service executable path contains spaces and is not enclosed in quotes, Windows interprets the path ambiguously during service startup. The operating system attempts to locate the executable by testing progressively longer portions of the path at each space boundary.

For instance, if the Mikogo-Service is installed with a path like C:\Program Files\Mikogo\Mikogo-Service.exe, Windows will first attempt to execute C:\Program.exe, then C:\Program Files\Mikogo\Mikogo-Service.exe. An attacker with write access to directories in the search path can place a malicious executable (e.g., Program.exe in C:\) that will be executed with the service's privileges.

Root Cause

The root cause is improper quoting of the service binary path in the Windows registry during Mikogo installation. The installer fails to wrap the ImagePath registry value in quotation marks, creating an ambiguous path resolution scenario. This configuration oversight allows the Windows Service Control Manager (SCM) to misinterpret the intended executable location when spaces are present in directory names.

Attack Vector

The attack requires local access to the vulnerable system. An attacker must have write permissions to a directory in the unquoted path hierarchy (such as C:\ or other intermediate directories). The attacker places a specially crafted executable at one of these locations with a name matching the truncated path component. When the Mikogo-Service starts (either manually, automatically at boot, or when triggered by a system event), the malicious executable runs with LocalSystem privileges instead of the legitimate service binary.

The exploitation workflow involves:

1. Identifying the unquoted service path via registry inspection or service enumeration
2. Determining which path locations are writable by the current user
3. Placing a malicious payload at the appropriate location
4. Triggering a service restart or waiting for system reboot

Detection Methods for CVE-2019-25308

Indicators of Compromise

• Unexpected executables named Program.exe or similar in root directories (e.g., C:\Program.exe)
• Unusual processes running with LocalSystem privileges that do not match expected service binaries
• Modified timestamps on directories within the Mikogo installation path
• Suspicious entries in Windows Event Log related to service startup failures followed by successful execution

Detection Strategies

• Enumerate all Windows services with unquoted paths using PowerShell: Get-WmiObject win32_service | Where-Object {$_.PathName -notlike '"*"' -and $_.PathName -like '* *'}
• Monitor file creation events in root directories and common installation paths for executable files
• Implement SentinelOne's behavioral AI to detect privilege escalation patterns associated with service abuse
• Review Windows Security Event ID 4688 (Process Creation) for unexpected parent-child process relationships involving services

Monitoring Recommendations

• Configure file integrity monitoring on sensitive directories such as C:\ and C:\Program Files\
• Enable detailed Windows service audit logging to track service start, stop, and modification events
• Deploy SentinelOne endpoint protection with real-time process monitoring to detect anomalous service behavior
• Regularly scan for unquoted service paths as part of vulnerability management programs

How to Mitigate CVE-2019-25308

Immediate Actions Required

• Audit the Mikogo-Service registry entry at HKLM\SYSTEM\CurrentControlSet\Services\Mikogo-Service and add quotation marks around the ImagePath value
• Verify no unauthorized executables exist in root directories or intermediate path locations
• Consider uninstalling Mikogo 5.2.2.150317 if not required for business operations
• Implement the principle of least privilege to restrict write access to sensitive system directories

Patch Information

No vendor patch information is currently available. The vulnerability was documented in Exploit-DB #47510. Additional technical details can be found in the VulnCheck Mikogo Advisory. Organizations should contact Mikogo vendor support for remediation guidance or apply manual registry corrections.

Workarounds

• Manually quote the service path in the Windows registry by modifying the ImagePath value to include quotation marks
• Restrict write permissions on directories in the service path hierarchy using NTFS ACLs
• Implement application whitelisting to prevent execution of unauthorized binaries
• Use Group Policy to enforce strict service configuration standards across the enterprise

# Manual registry fix to quote the service path
reg add "HKLM\SYSTEM\CurrentControlSet\Services\Mikogo-Service" /v ImagePath /t REG_EXPAND_SZ /d "\"C:\Program Files\Mikogo\Mikogo-Service.exe\"" /f