CVE-2021-3550
📋 TL;DR
This CVE describes a DLL search path vulnerability in Lenovo PCManager that could allow local attackers to escalate privileges by placing a malicious DLL in a directory that the application searches before loading legitimate libraries. Users running Lenovo PCManager versions below 3.0.500.5102 on Windows systems are affected.
💻 Affected Systems
- Lenovo PCManager
📦 What is this software?
Pcmanager by Lenovo
⚠️ Risk & Real-World Impact
Worst Case
An attacker with local access could execute arbitrary code with SYSTEM/administrator privileges, potentially gaining full control of the system.
Likely Case
Local privilege escalation allowing attackers to gain administrative rights on compromised systems.
If Mitigated
Limited impact if proper access controls prevent unauthorized local execution or if vulnerable software is not installed.
🎯 Exploit Status
DLL hijacking vulnerabilities typically have low exploitation complexity but require local access and ability to write to specific directories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.0.500.5102 and later
Vendor Advisory: https://iknow.lenovo.com.cn/detail/dc_197169.html
Restart Required: Yes
Instructions:
1. Download Lenovo PCManager version 3.0.500.5102 or later from official Lenovo sources. 2. Run the installer to update the software. 3. Restart the system to ensure changes take effect.
🔧 Temporary Workarounds
Remove vulnerable software
windowsUninstall Lenovo PCManager if not required for system functionality
Control Panel > Programs > Uninstall a program > Select Lenovo PCManager > Uninstall
Restrict directory permissions
windowsSet restrictive permissions on directories where DLL hijacking could occur
icacls "C:\Program Files\Lenovo\PCManager" /deny Everyone:(OI)(CI)(WD,AD,RX)
🧯 If You Can't Patch
- Restrict local user access to prevent unauthorized users from executing applications
- Implement application whitelisting to control which applications can run on the system
🔍 How to Verify
Check if Vulnerable:
Check Lenovo PCManager version in Control Panel > Programs > Programs and FeaturesCheck Version:
wmic product where name="Lenovo PCManager" get versionVerify Fix Applied:
Verify installed version is 3.0.500.5102 or higher and check that the application loads properly📡 Detection & Monitoring
Log Indicators:
- Unusual DLL loading from non-standard paths
- Failed DLL loading attempts from PCManager process
Network Indicators:
- Not applicable - local vulnerability
SIEM Query:
Process Creation where Image contains "PCManager" AND CommandLine contains unusual DLL paths