CVE-2021-3464
📋 TL;DR
This vulnerability allows local attackers to escalate privileges by exploiting a DLL search path issue in Lenovo PCManager. Attackers can place malicious DLLs in directories where the application searches, leading to arbitrary code execution with higher privileges. Users running vulnerable versions of Lenovo PCManager on Windows systems are affected.
💻 Affected Systems
- Lenovo PCManager
📦 What is this software?
Pcmanager by Lenovo
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with SYSTEM/administrator privileges, enabling complete control over the affected system, data theft, and lateral movement.
Likely Case
Local privilege escalation allowing attackers to bypass security controls, install malware, or access restricted resources on the compromised system.
If Mitigated
Limited impact if proper application whitelisting, DLL search path restrictions, and least privilege principles are enforced.
🎯 Exploit Status
DLL hijacking vulnerabilities are well-understood attack vectors with established exploitation techniques, though no specific public exploit for this CVE is documented.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.0.400.3252 and later
Vendor Advisory: https://iknow.lenovo.com.cn/detail/dc_196156.html
Restart Required: Yes
Instructions:
1. Open Lenovo PCManager. 2. Check for updates in settings. 3. Install version 3.0.400.3252 or later. 4. Restart the system to ensure changes take effect.
🔧 Temporary Workarounds
Restrict DLL search paths
windowsConfigure Windows to restrict DLL search paths using Group Policy or registry settings to prevent loading from untrusted directories.
reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager" /v SafeDllSearchMode /t REG_DWORD /d 1 /f
Remove vulnerable software
windowsUninstall Lenovo PCManager if not required for system functionality.
appwiz.cpl
Select Lenovo PCManager and click Uninstall
🧯 If You Can't Patch
- Implement strict application control policies to prevent unauthorized DLL loading
- Enforce least privilege principles and restrict local user permissions to limit attack surface
🔍 How to Verify
Check if Vulnerable:
Check Lenovo PCManager version: Open PCManager → Settings → About. If version is below 3.0.400.3252, system is vulnerable.Check Version:
wmic product where "name like 'Lenovo PCManager%'" get versionVerify Fix Applied:
Confirm PCManager version is 3.0.400.3252 or higher and verify no unauthorized DLLs are loaded from untrusted directories.📡 Detection & Monitoring
Log Indicators:
- Windows Event Logs showing DLL loading from unusual directories
- Process Monitor logs showing PCManager loading DLLs from user-writable paths
Network Indicators:
- No network indicators as this is local exploitation
SIEM Query:
EventID=7 AND ProcessName="PCManager.exe" AND ImageLoaded CONTAINS "users\" OR ImageLoaded CONTAINS "temp\"