CVE-2023-51837
📋 TL;DR
MeshCentral 1.1.16 fails to properly validate SSL certificates when establishing connections, allowing man-in-the-middle attackers to intercept and manipulate communications. This affects all users running the vulnerable version of MeshCentral server software.
💻 Affected Systems
- Ylianst MeshCentral
📦 What is this software?
Meshcentral by Meshcentral
⚠️ Risk & Real-World Impact
Worst Case
Attackers can perform full man-in-the-middle attacks, intercepting all communications including authentication credentials, remote control sessions, and sensitive data transfers.
Likely Case
Network-based attackers can intercept administrative credentials and gain unauthorized access to managed systems through the MeshCentral platform.
If Mitigated
With proper network segmentation and monitoring, impact is limited to potential credential exposure within the segmented network zone.
🎯 Exploit Status
Exploitation requires network position for man-in-the-middle attack but no authentication to target system.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.1.17 or later
Vendor Advisory: https://github.com/Ylianst/MeshCentral
Restart Required: Yes
Instructions:
1. Backup current MeshCentral configuration. 2. Update MeshCentral using npm update command. 3. Restart MeshCentral service. 4. Verify SSL certificate validation is working.
🔧 Temporary Workarounds
Network Segmentation
allIsolate MeshCentral server to trusted network segments only
VPN Tunnel
allRequire all MeshCentral connections through VPN with certificate validation
🧯 If You Can't Patch
- Deploy network monitoring for SSL/TLS anomalies and man-in-the-middle indicators
- Implement strict network access controls limiting which hosts can communicate with MeshCentral server
🔍 How to Verify
Check if Vulnerable:
Check MeshCentral version in web interface or via 'npm list meshcentral' commandCheck Version:
npm list meshcentral | grep meshcentralVerify Fix Applied:
Test SSL certificate validation by attempting to connect with invalid certificates - connection should fail📡 Detection & Monitoring
Log Indicators:
- Failed SSL handshakes that should succeed
- Unexpected certificate changes
Network Indicators:
- SSL/TLS connections without proper certificate validation
- Man-in-the-middle attack patterns
SIEM Query:
event.category:network AND (ssl.validation:failed OR tls.certificate.invalid:true) AND destination.port:4430🔗 References
- https://github.com/Ylianst/MeshCentral/blob/master/mpsserver.js
- https://github.com/tianjk99/Cryptographic-Misuses/blob/main/Bug_MeshCentral.md
- https://github.com/tianjk99/Cryptographic-Misuses/blob/main/CVE-2023-51837.md
- https://github.com/Ylianst/MeshCentral/blob/master/mpsserver.js
- https://github.com/tianjk99/Cryptographic-Misuses/blob/main/Bug_MeshCentral.md
- https://github.com/tianjk99/Cryptographic-Misuses/blob/main/CVE-2023-51837.md
