CVE-2016-20055: IObit Advanced SystemCare Privilege Escalation

CVE-2016-20055 Overview

CVE-2016-20055 is an unquoted service path vulnerability affecting IObit Advanced SystemCare 10.0.2. The AdvancedSystemCareService10 service contains an unquoted service path that allows local attackers to escalate privileges. When the service is configured with a path containing spaces and the path is not properly enclosed in quotation marks, Windows may execute a malicious executable placed in an intermediate directory before reaching the intended service binary.

Attackers with local access can place a malicious executable in the service path and trigger privilege escalation when the service restarts or the system reboots, resulting in arbitrary code execution with LocalSystem privileges.

Critical Impact

Local privilege escalation to SYSTEM-level access, allowing complete compromise of the affected Windows system.

Affected Products

• IObit Advanced SystemCare 10.0.2
• AdvancedSystemCareService10 Windows Service
• Earlier versions of IObit Advanced SystemCare may also be affected

Discovery Timeline

• 2026-04-04 - CVE CVE-2016-20055 published to NVD
• 2026-04-07 - Last updated in NVD database

Technical Details for CVE-2016-20055

Vulnerability Analysis

This vulnerability is classified as CWE-428: Unquoted Search Path or Element. In Windows operating systems, when a service executable path contains spaces and is not enclosed in quotation marks, the Service Control Manager (SCM) parses the path ambiguously. Windows attempts to locate executables by iteratively parsing the path at each space character.

For example, if a service path is configured as C:\Program Files\IObit\Advanced SystemCare\ASCService.exe, Windows will attempt to execute the following in order:

1. C:\Program.exe
2. C:\Program Files\IObit\Advanced.exe
3. C:\Program Files\IObit\Advanced SystemCare\ASCService.exe

An attacker with write access to any of the intermediate directories can place a malicious executable at one of these parsed locations. When the service starts (during system boot or manual restart), the malicious binary executes with the privileges of the service account—typically LocalSystem, which has full administrative access to the system.

Root Cause

The root cause is improper configuration of the Windows service registration. The AdvancedSystemCareService10 service was registered with an unquoted path to its executable. The installer or service configuration code failed to enclose the service binary path in quotation marks, leaving the service vulnerable to path interception attacks.

This is a common oversight in software installation routines where developers do not account for the Windows path parsing behavior when paths contain space characters.

Attack Vector

The attack requires local access to the system with write permissions to an intermediate directory in the service path (such as C:\Program Files\IObit\). The attacker must:

1. Identify the unquoted service path using tools like wmic service get name,pathname,displayname,startmode | findstr /i "auto"
2. Place a malicious executable at an intermediate parsed location (e.g., C:\Program Files\IObit\Advanced.exe)
3. Wait for the system to reboot or manually trigger a service restart
4. The malicious executable runs with LocalSystem privileges, granting full system access

This vulnerability does not require user interaction once the malicious binary is in place—the service restart triggers execution automatically.

Detection Methods for CVE-2016-20055

Indicators of Compromise

• Presence of unexpected executable files in intermediate directories along the IObit installation path (e.g., C:\Program.exe, C:\Program Files\IObit\Advanced.exe)
• Unusual processes spawned by the AdvancedSystemCareService10 service
• New user accounts or unauthorized administrative access following service restart
• Suspicious modifications to the C:\Program Files\IObit\ directory structure

Detection Strategies

• Use Windows Management Instrumentation (WMI) queries to enumerate services with unquoted paths: wmic service get name,pathname | findstr /i /v """"
• Monitor for file creation events in directories that are early in the service path parsing order
• Implement file integrity monitoring on the IObit installation directory hierarchy
• Review Windows Event Logs for service start failures followed by unexpected process execution

Monitoring Recommendations

• Deploy endpoint detection and response (EDR) solutions to monitor process creation with SYSTEM privileges
• Configure alerts for new executables created in C:\Program Files\ root and vendor-specific subdirectories
• Monitor service configuration changes via Windows Security Event ID 4697 (Service Installed)
• Establish baseline behavior for AdvancedSystemCareService10 and alert on anomalies

How to Mitigate CVE-2016-20055

Immediate Actions Required

• Audit all Windows services on affected systems for unquoted service paths using wmic or PowerShell
• Manually correct the service path by enclosing it in quotation marks using the Registry Editor or sc config command
• Verify no unauthorized executables exist in intermediate directories along the service path
• Update IObit Advanced SystemCare to the latest available version that addresses this configuration issue

Patch Information

Users should upgrade to a newer version of IObit Advanced SystemCare that properly quotes the service executable path. The IObit Advanced SystemCare download page provides the latest versions. Additionally, the VulnCheck IObit Advisory provides detailed guidance on this vulnerability.

For technical details and proof-of-concept information, refer to Exploit-DB #40577.

Workarounds

• Manually fix the unquoted service path by modifying the registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\AdvancedSystemCareService10 and enclosing the ImagePath value in quotation marks
• Restrict write permissions on C:\Program Files\IObit\ and parent directories to administrators only
• Implement application whitelisting to prevent unauthorized executables from running with elevated privileges
• Consider uninstalling affected software if it is not essential and a patched version is unavailable

# Configuration example - Fix unquoted service path using sc command
sc config "AdvancedSystemCareService10" binPath= "\"C:\Program Files\IObit\Advanced SystemCare\ASCService.exe\""

# Alternatively, use PowerShell to identify and report unquoted service paths
Get-WmiObject win32_service | Where-Object {$_.PathName -notlike '"*' -and $_.PathName -like '* *.exe*'} | Select-Object Name, PathName