CVE-2017-3756
📋 TL;DR
This CVE describes a local privilege escalation vulnerability in Lenovo's Active Protection System for ThinkPad laptops. An attacker with existing local access could exploit an unquoted service path to execute arbitrary code with SYSTEM/administrator privileges. Only ThinkPad systems running vulnerable versions of Lenovo Active Protection System are affected.
💻 Affected Systems
- Lenovo Active Protection System
📦 What is this software?
Thinkpad Yoga 11e Broadwell Bios by Lenovo
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise where an attacker with initial local access gains full administrative control, enabling installation of persistent malware, credential theft, and lateral movement.
Likely Case
Local attacker escalates privileges to install keyloggers, backdoors, or other malicious software while evading detection by user account controls.
If Mitigated
Attack fails due to patched software or proper endpoint security controls detecting suspicious privilege escalation attempts.
🎯 Exploit Status
Exploitation requires local access first. Unquoted service path vulnerabilities are well-understood and relatively easy to exploit once initial access is obtained.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.82.0.17 or later
Vendor Advisory: https://support.lenovo.com/us/en/product_security/LEN-15765
Restart Required: Yes
Instructions:
1. Download Lenovo Active Protection System version 1.82.0.17 or later from Lenovo's support site. 2. Run the installer with administrative privileges. 3. Restart the system to complete the installation.
🔧 Temporary Workarounds
Remove vulnerable software
windowsUninstall Lenovo Active Protection System if not required for system functionality
Control Panel > Programs and Features > Uninstall Lenovo Active Protection System
Restrict service permissions
windowsSet stricter permissions on the service executable and directories in the service path
icacls "C:\Program Files\Lenovo\Active Protection System\" /deny Users:(OI)(CI)F
🧯 If You Can't Patch
- Implement strict endpoint security controls to detect and prevent privilege escalation attempts
- Restrict local user privileges and implement least privilege access controls
🔍 How to Verify
Check if Vulnerable:
Check Lenovo Active Protection System version in Control Panel > Programs and Features. If version is earlier than 1.82.0.17, the system is vulnerable.Check Version:
wmic product where "name like 'Lenovo Active Protection System%'" get versionVerify Fix Applied:
Verify Lenovo Active Protection System version is 1.82.0.17 or later in Control Panel > Programs and Features.📡 Detection & Monitoring
Log Indicators:
- Windows Event Logs showing unexpected service creation or modification
- Security logs showing privilege escalation attempts
Network Indicators:
- None - this is a local attack
SIEM Query:
EventID=4688 AND (NewProcessName LIKE '*\Lenovo\Active Protection System\*' OR CommandLine LIKE '*\Lenovo\Active Protection System\*')