CVE-2025-58123
📋 TL;DR
CVE-2025-58123 is an improper certificate validation vulnerability in the Checkmk Exchange BGP Monitoring plugin. Attackers in a man-in-the-middle position can intercept and potentially manipulate traffic between the plugin and monitored BGP devices. Organizations using the vulnerable plugin version for BGP monitoring are affected.
💻 Affected Systems
- Checkmk Exchange BGP Monitoring plugin
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers intercept sensitive BGP monitoring data, inject false routing information, or disrupt network monitoring entirely, potentially causing routing instability or data exfiltration.
Likely Case
Attackers intercept BGP monitoring traffic to gather network topology information, monitor routing changes, or disrupt monitoring alerts without full traffic manipulation.
If Mitigated
With proper network segmentation and certificate validation, impact is limited to potential monitoring data leakage without routing manipulation.
🎯 Exploit Status
Exploitation requires man-in-the-middle position between Checkmk server and monitored BGP devices. No public exploit code available as of analysis.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: BGP Monitoring plugin 2.1.0
Vendor Advisory: https://exchange.checkmk.com/p/bgp-mon
Restart Required: Yes
Instructions:
1. Log into Checkmk web interface. 2. Navigate to Setup > Extensions. 3. Update BGP Monitoring plugin to version 2.1.0 or later. 4. Restart Checkmk services. 5. Verify plugin functionality.
🔧 Temporary Workarounds
Network segmentation
allIsolate Checkmk server and BGP devices on trusted network segments to prevent man-in-the-middle attacks
Disable plugin temporarily
linuxTemporarily disable BGP monitoring if immediate patching isn't possible
omd stop [SITE]
🧯 If You Can't Patch
- Implement strict network access controls between Checkmk and BGP devices
- Monitor for unusual certificate validation failures in Checkmk logs
🔍 How to Verify
Check if Vulnerable:
Check installed plugin version via Checkmk web interface: Setup > Extensions > Installed extensions, look for BGP Monitoring plugin versionCheck Version:
grep 'bgp-monitoring' /omd/sites/[SITE]/var/check_mk/packages.txtVerify Fix Applied:
Verify BGP Monitoring plugin version is 2.1.0 or higher and certificate validation is functioning for BGP connections📡 Detection & Monitoring
Log Indicators:
- Certificate validation failures in Checkmk logs
- Unexpected BGP connection resets
- SSL/TLS handshake errors with BGP devices
Network Indicators:
- Unusual traffic patterns between Checkmk and BGP devices
- SSL/TLS interception attempts
SIEM Query:
source="checkmk.log" AND ("certificate" OR "validation" OR "SSL") AND "BGP"