CVE-2020-36959: IDT PC Audio Privilege Escalation Issue

CVE-2020-36959 Overview

CVE-2020-36959 is an unquoted service path vulnerability affecting IDT PC Audio version 1.0.6499.0. This security flaw allows local users to potentially execute arbitrary code with elevated system privileges by exploiting the improperly quoted service path in the STacSV service. When Windows attempts to start the service, it may inadvertently execute a malicious binary placed in a directory along the unquoted path, granting the attacker LocalSystem account permissions.

Critical Impact

Local attackers can achieve privilege escalation to SYSTEM level by exploiting the unquoted service path, enabling complete system compromise on affected Windows hosts.

Affected Products

• IDT PC Audio version 1.0.6499.0
• Windows systems with the STacSV service installed
• Systems with write access to directories in the service path

Discovery Timeline

• 2026-01-26 - CVE CVE-2020-36959 published to NVD
• 2026-01-27 - Last updated in NVD database

Technical Details for CVE-2020-36959

Vulnerability Analysis

This vulnerability is classified as CWE-428 (Unquoted Search Path or Element). The IDT PC Audio software installs the STacSV service with a binary path that contains spaces but is not enclosed in quotation marks. When Windows services are configured with unquoted paths containing spaces, the operating system's path parsing mechanism creates an exploitable condition.

During service startup, Windows interprets the unquoted path ambiguously. For example, if the service path is C:\Program Files\IDT\WDM\STacSV.exe, Windows will attempt to execute binaries in the following order: C:\Program.exe, C:\Program Files\IDT\WDM\STacSV.exe. An attacker with write access to C:\ could place a malicious Program.exe that would execute with LocalSystem privileges before the legitimate service binary.

Root Cause

The root cause stems from improper configuration during the software installation process. The service registration in the Windows registry fails to enclose the ImagePath value in quotation marks when the path contains spaces. This is a common oversight in Windows application development that creates a privilege escalation vector. The STacSV service runs under the LocalSystem account, meaning any code executed through this vulnerability inherits the highest level of system privileges available.

Attack Vector

The attack requires local access to the target system and write permissions to a directory within the unquoted service path. An attacker would:

1. Identify the unquoted service path for STacSV
2. Determine writable directories along the path segments
3. Place a malicious executable with a name matching a truncated path segment
4. Wait for the service to restart or trigger a system reboot
5. The malicious binary executes with SYSTEM privileges

Since this is a local attack vector, the attacker must already have some level of access to the target machine. However, this vulnerability enables escalation from a low-privileged user account to full SYSTEM control. Technical details and proof-of-concept information are available in the Exploit-DB #49191 entry and the VulnCheck Advisory.

Detection Methods for CVE-2020-36959

Indicators of Compromise

• Unexpected executable files in C:\ root directory or C:\Program Files\ with names like Program.exe
• Unusual process execution events from the STacSV service parent process
• Registry modifications to the STacSV service ImagePath value
• Anomalous file creation events in directories along the service path

Detection Strategies

• Monitor for executable file creation in root directories and common path segments like C:\Program.exe or C:\Program Files\Common.exe
• Query Windows services for unquoted paths using PowerShell: Get-WmiObject win32_service | Where-Object {$_.PathName -notlike '"*"' -and $_.PathName -like '* *'}
• Implement endpoint detection rules for suspicious binaries executing under the STacSV service context
• Review Windows Security Event logs for service-related process creation (Event ID 7045)

Monitoring Recommendations

• Configure SentinelOne to alert on new executable file creation in system root directories
• Enable behavioral monitoring for privilege escalation patterns involving Windows services
• Deploy file integrity monitoring on directories commonly targeted by unquoted service path attacks
• Monitor for service restarts or modifications to the STacSV service configuration

How to Mitigate CVE-2020-36959

Immediate Actions Required

• Audit all installed Windows services for unquoted paths using automated scanning tools
• Manually add quotation marks to the STacSV service ImagePath in the registry
• Restrict write permissions on directories in the service path to administrators only
• Consider removing or disabling the IDT PC Audio software if not required for business operations

Patch Information

No official vendor patch has been identified in the available advisory data. Organizations should contact IDT or their hardware vendor for updated driver packages that address this vulnerability. The PCON Life Download Resource may contain relevant software information.

Workarounds

• Manually correct the registry entry by adding quotation marks around the service path
• Use Windows built-in sc command to reconfigure the service with a properly quoted path
• Implement application whitelisting to prevent unauthorized executables from running in sensitive directories
• Deploy endpoint protection solutions like SentinelOne that can detect and block privilege escalation attempts

# Configuration example - Fix unquoted service path via registry
# Run as Administrator in PowerShell

# Query current service path
Get-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Services\STacSV" -Name ImagePath

# Update with quoted path (adjust path as needed for your installation)
Set-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Services\STacSV" -Name ImagePath -Value '"C:\Program Files\IDT\WDM\STacSV64.exe"'

# Verify the change
Get-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Services\STacSV" -Name ImagePath