CVE-2020-36930: SysGauge Server Privilege Escalation

CVE-2020-36930 Overview

CVE-2020-36930 is an unquoted service path vulnerability affecting SysGauge Server version 7.9.18. This security flaw exists in the binary path configuration where the service executable path C:\Program Files\SysGauge Server\bin\sysgaus.exe is not properly quoted. Local attackers can exploit this misconfiguration to inject malicious executables into the service path and potentially escalate privileges on the affected system.

Unquoted service path vulnerabilities (CWE-428) occur when Windows services are configured with executable paths containing spaces but lacking proper quotation marks. When Windows attempts to locate the service binary, it parses the path sequentially, checking for executables at each space-delimited segment. This behavior can be exploited by placing a malicious executable at one of these intermediate path locations.

Critical Impact

Local attackers with write access to the C:\Program Files\ directory structure can achieve privilege escalation by placing a malicious executable that Windows will execute with elevated service privileges.

Affected Products

• SysGauge Server 7.9.18
• Earlier versions of SysGauge Server may also be affected

Discovery Timeline

• 2026-01-16 - CVE-2020-36930 published to NVD
• 2026-01-16 - Last updated in NVD database

Technical Details for CVE-2020-36930

Vulnerability Analysis

This vulnerability stems from improper service configuration in SysGauge Server where the executable path is stored without enclosing quotation marks. The affected service path C:\Program Files\SysGauge Server\bin\sysgaus.exe contains multiple spaces, creating potential exploitation points.

When Windows starts a service with an unquoted path containing spaces, the system uses a predictable path resolution algorithm. It attempts to execute binaries at each space-separated segment of the path before ultimately reaching the intended executable. This creates an opportunity for local privilege escalation when an attacker can write to any of the intermediate path locations.

The attack requires local access and the ability to write files to directories within the service path hierarchy. Successful exploitation allows attackers to execute arbitrary code with the privileges of the service account, which often runs as SYSTEM or with elevated permissions.

Root Cause

The root cause is the failure to properly quote the service binary path during installation or configuration of SysGauge Server. When the ImagePath registry value is set without quotation marks around paths containing spaces, Windows interprets the spaces as argument delimiters during service startup. This is classified as CWE-428 (Unquoted Search Path or Element).

Attack Vector

The attack vector is local, requiring the attacker to have authenticated access to the target system and write permissions to at least one directory in the service path hierarchy. The attacker can exploit the vulnerability by:

1. Identifying the unquoted service path in the Windows registry or via tools like wmic or sc qc
2. Placing a malicious executable at an intermediate path location (e.g., C:\Program.exe or C:\Program Files\SysGauge.exe)
3. Waiting for or triggering a service restart
4. Gaining code execution with the service's elevated privileges

Technical details and proof-of-concept information are available in the Exploit-DB #50009 advisory.

Detection Methods for CVE-2020-36930

Indicators of Compromise

• Presence of unexpected executables in C:\Program.exe, C:\Program Files\SysGauge.exe, or similar intermediate path locations
• Unexpected process executions from the SysGauge Server service context
• Suspicious file creation events in the C:\Program Files\ directory hierarchy
• Service control events followed by unusual child process spawning

Detection Strategies

• Query Windows services for unquoted paths using PowerShell: Get-WmiObject Win32_Service | Where-Object { $_.PathName -match '^[^\"]+\s.+\.exe' }
• Monitor for file creation events in C:\ and C:\Program Files\ directories for executables with names matching path segments
• Implement application whitelisting to prevent execution of unauthorized binaries
• Use SentinelOne Singularity to detect privilege escalation attempts and unauthorized process execution chains

Monitoring Recommendations

• Enable Windows Security Event logging for service control operations (Event IDs 7045, 7040)
• Monitor file system audit logs for executable creation in sensitive path locations
• Implement real-time endpoint detection for service-based privilege escalation patterns
• Alert on any process spawned by SysGauge Server service that doesn't match expected behavior

How to Mitigate CVE-2020-36930

Immediate Actions Required

• Audit all Windows services for unquoted paths using enumeration scripts or vulnerability scanners
• Add proper quotation marks around the SysGauge Server service path in the Windows registry
• Restrict write permissions on the C:\Program Files\ directory hierarchy to administrators only
• Monitor for any suspicious executables that may have already been placed in exploitable locations

Patch Information

No official patch information is available from the vendor at this time. Organizations should check the SysGauge Website for updates and security advisories. Additional vulnerability details can be found in the VulnCheck Advisory.

Workarounds

• Manually correct the service path by adding quotation marks in the Windows registry under HKLM\SYSTEM\CurrentControlSet\Services\<ServiceName>\ImagePath
• Implement strict file system ACLs to prevent non-administrators from creating files in vulnerable path locations
• Consider uninstalling or disabling SysGauge Server until an official patch is released
• Use endpoint protection solutions like SentinelOne to detect and block exploitation attempts

# Registry fix to quote the service path (run as Administrator)
reg add "HKLM\SYSTEM\CurrentControlSet\Services\SysGauge Server" /v ImagePath /t REG_EXPAND_SZ /d "\"C:\Program Files\SysGauge Server\bin\sysgaus.exe\"" /f