CVE-2021-31844
📋 TL;DR
A local buffer overflow vulnerability in McAfee Data Loss Prevention Endpoint for Windows allows attackers to execute arbitrary code with elevated privileges by placing malicious Ami Pro (.sam) files on the system and triggering a DLP scan. This affects local users who can place files on the system and trigger scans. The vulnerability stems from improper size checks when processing these files.
💻 Affected Systems
- McAfee Data Loss Prevention Endpoint
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with SYSTEM/administrator privileges, allowing installation of persistent malware, data theft, or lateral movement across the network.
Likely Case
Local privilege escalation leading to administrative control over the affected endpoint, enabling further attacks within the environment.
If Mitigated
Limited impact if proper file access controls prevent unauthorized users from placing files and triggering scans, though the vulnerability remains present.
🎯 Exploit Status
Requires local access to place files and trigger DLP scans. No public exploit code is known, but the vulnerability details are published.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 11.6.200 and later
Vendor Advisory: https://kc.mcafee.com/corporate/index?page=content&id=SB10368
Restart Required: Yes
Instructions:
1. Download McAfee DLP Endpoint version 11.6.200 or later from official sources. 2. Deploy the update through your management console or manually install. 3. Restart affected Windows systems to complete the installation.
🔧 Temporary Workarounds
Disable DLP scanning for .sam files
windowsConfigure DLP policies to exclude Ami Pro (.sam) files from scanning to prevent exploitation.
Configure via McAfee ePolicy Orchestrator (ePO) console: Navigate to DLP Policy Manager > File Policies > Add exclusion for *.sam files
Restrict file placement permissions
windowsImplement strict file system permissions to prevent unauthorized users from placing .sam files in scannable locations.
Use Windows Group Policy or manual ACLs to restrict write access to directories where DLP scans occur
🧯 If You Can't Patch
- Implement strict access controls to prevent local users from placing arbitrary files on systems.
- Monitor for suspicious .sam file creation and DLP scan triggers using endpoint detection tools.
🔍 How to Verify
Check if Vulnerable:
Check the McAfee DLP Endpoint version in the Windows Control Panel > Programs and Features, or via command line: wmic product where "name like 'McAfee Data Loss Prevention Endpoint'" get versionCheck Version:
wmic product where "name like 'McAfee Data Loss Prevention Endpoint'" get versionVerify Fix Applied:
Confirm the version is 11.6.200 or higher using the same method as above, and verify no errors occur when scanning test .sam files.📡 Detection & Monitoring
Log Indicators:
- Unusual DLP scan errors or crashes related to .sam file processing in McAfee logs
- Windows Event Logs showing privilege escalation or unexpected process execution
Network Indicators:
- Unusual outbound connections from DLP processes post-scan, though exploitation is local
SIEM Query:
Example: (source="McAfee DLP" AND "*.sam") OR (event_id=4688 AND process_name="dlp*.exe" AND parent_process="explorer.exe")