CVE-2023-27247
📋 TL;DR
CVE-2023-27247 is a privilege escalation vulnerability in Cynet Client Agent v4.6.0.8010 where attackers with Administrator rights can disable EDR (Endpoint Detection and Response) functions by manipulating process privilege tokens. This affects organizations using the vulnerable Cynet agent version, allowing malicious insiders or compromised admin accounts to bypass security monitoring.
💻 Affected Systems
- Cynet Client Agent
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers with administrative access completely disable EDR protection, allowing undetected malware execution, lateral movement, and data exfiltration across the network.
Likely Case
Malicious insiders or compromised admin accounts disable EDR on specific endpoints to conduct unauthorized activities without detection.
If Mitigated
With proper access controls and monitoring, impact is limited to isolated incidents that can be quickly detected and contained.
🎯 Exploit Status
Exploitation requires administrative privileges. Proof-of-concept details are publicly available in GitHub repositories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v4.6.0.8011 or later
Vendor Advisory: https://github.com/advisories/GHSA-hmjw-7429-p2vc
Restart Required: Yes
Instructions:
1. Update Cynet Client Agent to version 4.6.0.8011 or later. 2. Restart affected endpoints. 3. Verify agent is running with updated version.
🔧 Temporary Workarounds
Restrict Local Administrator Access
windowsLimit local administrator privileges to essential personnel only to reduce attack surface.
Use Group Policy to restrict local admin rights: Computer Configuration > Policies > Windows Settings > Security Settings > Restricted Groups
Monitor Privilege Token Manipulation
windowsImplement monitoring for process token manipulation attempts.
Enable Windows Event Log auditing for privilege use (Event ID 4672, 4673)
🧯 If You Can't Patch
- Implement strict least-privilege access controls to limit who has local administrator rights
- Deploy additional endpoint monitoring solutions to detect EDR tampering attempts
🔍 How to Verify
Check if Vulnerable:
Check Cynet agent version: Open Cynet Management Console or check agent properties on endpoint.Check Version:
wmic product where name="Cynet Client Agent" get versionVerify Fix Applied:
Verify agent version is 4.6.0.8011 or later and EDR functions are operational.📡 Detection & Monitoring
Log Indicators:
- Windows Event Logs showing privilege token manipulation (Event ID 4672, 4673)
- Cynet agent logs showing EDR service stoppage
Network Indicators:
- Unusual decrease in EDR telemetry data from endpoints
- Suspicious process execution without EDR alerts
SIEM Query:
source="windows" AND (event_id=4672 OR event_id=4673) AND process_name="*cynet*"