CVE-2021-23878
📋 TL;DR
This vulnerability allows a local user on a Windows system to view McAfee Endpoint Security settings and credentials stored in clear text in process memory. It affects McAfee ENS for Windows versions prior to 10.7.0 February 2021 Update. Exploitation requires the attacker to access memory immediately after an administrator makes configuration changes.
💻 Affected Systems
- McAfee Endpoint Security (ENS) for Windows
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Local attackers could extract administrative credentials and security configuration details, potentially enabling privilege escalation, lateral movement, or disabling of security controls.
Likely Case
Local users with basic access could view sensitive ENS configuration data, potentially learning about security policies, exclusions, or other protected settings.
If Mitigated
With proper access controls and timely patching, the risk is limited to authorized users who shouldn't have access to sensitive memory locations.
🎯 Exploit Status
Requires local access, timing (immediately after admin configuration), and ability to read process memory. Not a remote exploit.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 10.7.0 February 2021 Update or later
Vendor Advisory: https://kc.mcafee.com/corporate/index?page=content&id=SB10345
Restart Required: Yes
Instructions:
1. Download the ENS 10.7.0 February 2021 Update from McAfee. 2. Deploy the update through your management console or manually install. 3. Restart affected systems to complete the installation.
🔧 Temporary Workarounds
Restrict Local Access
windowsLimit local user access to systems running vulnerable ENS versions, especially for users who shouldn't have administrative privileges.
Monitor Process Memory Access
windowsImplement monitoring for unusual process memory access attempts on systems running ENS.
🧯 If You Can't Patch
- Implement strict access controls to limit who can log into systems running vulnerable ENS versions
- Monitor for unusual memory access patterns and investigate any unauthorized attempts to read process memory
🔍 How to Verify
Check if Vulnerable:
Check ENS version in McAfee console or via 'Get-MpComputerStatus' PowerShell command. If version is earlier than 10.7.0 February 2021 Update, system is vulnerable.Check Version:
Get-MpComputerStatus | Select-Object AMProductVersionVerify Fix Applied:
Verify ENS version is 10.7.0 February 2021 Update or later. Check that no sensitive data appears in clear text in process memory after configuration changes.📡 Detection & Monitoring
Log Indicators:
- Unusual process memory access events
- Failed attempts to access protected memory regions
- Multiple configuration changes in short timeframes
Network Indicators:
- Not applicable - local memory access only
SIEM Query:
EventID=4663 AND ObjectType=Process AND AccessMask=0x10 AND ProcessName contains 'mcshield' OR 'ens'