CVE-2019-9203
📋 TL;DR
This vulnerability allows attackers to bypass authorization in Nagios Incident Manager (IM) and close incidents via the API without proper authentication. It affects Nagios XI installations with IM component versions before 2.2.7. This could allow unauthorized manipulation of incident management data.
💻 Affected Systems
- Nagios XI with Incident Manager (IM) component
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers could systematically close all security incidents, hiding ongoing attacks and preventing proper incident response, potentially leading to undetected data breaches or system compromise.
Likely Case
Unauthorized users closing legitimate incidents, disrupting incident response workflows and potentially hiding security events from administrators.
If Mitigated
With proper network segmentation and API access controls, impact is limited to authorized users only, maintaining incident integrity.
🎯 Exploit Status
Exploitation requires API access but no authentication. Public exploit details exist in security advisories. The vulnerability is straightforward to exploit once API endpoint is identified.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Nagios IM 2.2.7 or later
Vendor Advisory: https://www.nagios.com/products/security/
Restart Required: Yes
Instructions:
1. Backup current Nagios XI configuration. 2. Update Nagios XI to latest version (5.6.0 or later includes IM 2.2.7). 3. Alternatively, update Incident Manager component to 2.2.7+. 4. Restart Nagios XI services. 5. Verify update via Nagios admin interface.
🔧 Temporary Workarounds
Restrict API Access
linuxBlock external access to Nagios XI API endpoints using firewall rules
iptables -A INPUT -p tcp --dport 80 -s ! trusted_network -j DROP
iptables -A INPUT -p tcp --dport 443 -s ! trusted_network -j DROP
Disable Incident Manager
allTemporarily disable the Incident Manager component if not essential
Navigate to Nagios XI Admin > Manage Components > Disable Incident Manager
🧯 If You Can't Patch
- Implement strict network segmentation to isolate Nagios XI from untrusted networks
- Enable detailed API access logging and monitor for unauthorized incident closure attempts
🔍 How to Verify
Check if Vulnerable:
Check Nagios XI admin interface > Help > About > Component Versions. Look for Incident Manager version below 2.2.7.Check Version:
grep 'nagiosim' /usr/local/nagiosxi/var/xiversion.log || cat /usr/local/nagiosxi/html/includes/config.inc.php | grep im_versionVerify Fix Applied:
Verify Incident Manager version shows 2.2.7 or higher in Nagios XI admin interface. Test API incident closure with unauthorized credentials should fail.📡 Detection & Monitoring
Log Indicators:
- Unauthorized API calls to /nagiosxi/api/incident endpoints
- Incident closure events from non-admin users in Nagios logs
Network Indicators:
- HTTP POST requests to incident API endpoints from unexpected source IPs
- Multiple incident closure requests in short timeframes
SIEM Query:
source="nagios.log" AND ("incident closed" OR "/api/incident") AND NOT user="admin"