CVE-2020-36861
📋 TL;DR
This CVE describes multiple cross-site scripting (XSS) vulnerabilities in Nagios XI's Core Config Manager (CCM). Attackers can inject malicious scripts into overlay UI elements and notification/check period pages, which execute in victims' browsers when they view those pages. Organizations running Nagios XI versions before 5.7.5 or CCM before 3.0.8 are affected.
💻 Affected Systems
- Nagios XI
- Nagios Core Config Manager (CCM)
📦 What is this software?
Nagios Xi by Nagios
⚠️ Risk & Real-World Impact
Worst Case
An authenticated attacker could steal administrator session cookies, perform actions as the victim user, or redirect users to malicious sites, potentially leading to complete system compromise if combined with other vulnerabilities.
Likely Case
Attackers with access to the Nagios XI interface could perform session hijacking, steal credentials, or deface monitoring pages, compromising the integrity of the monitoring system.
If Mitigated
With proper input validation and output encoding, the script injection would be neutralized, preventing execution in victim browsers.
🎯 Exploit Status
Exploitation requires the attacker to have access to the Nagios XI interface and the ability to inject malicious scripts into specific UI elements that other users will view.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Nagios XI 5.7.5 or CCM 3.0.8
Vendor Advisory: https://www.nagios.com/changelog/nagios-xi/
Restart Required: No
Instructions:
1. Log into Nagios XI as administrator. 2. Navigate to Admin > Check for Updates. 3. Follow the upgrade wizard to update to Nagios XI 5.7.5 or later. 4. Verify the update completed successfully.
🔧 Temporary Workarounds
Input Validation Enhancement
allImplement additional input validation for user-supplied data in overlay UI elements and notification/check period pages
Output Encoding
allApply proper output encoding to all user-controlled data displayed in the affected pages
🧯 If You Can't Patch
- Implement a web application firewall (WAF) with XSS protection rules
- Restrict access to Nagios XI interface to trusted users only using network segmentation and authentication controls
🔍 How to Verify
Check if Vulnerable:
Check Nagios XI version via Admin > System Status > Version Information. If version is below 5.7.5, the system is vulnerable.Check Version:
cat /usr/local/nagiosxi/var/xiversionVerify Fix Applied:
After updating, verify the version shows 5.7.5 or higher in Admin > System Status > Version Information.📡 Detection & Monitoring
Log Indicators:
- Unusual JavaScript payloads in web server access logs
- Multiple failed attempts to access restricted UI elements
- Suspicious user input patterns in application logs
Network Indicators:
- Unexpected JavaScript execution in Nagios XI web traffic
- Suspicious POST requests to overlay or notification pages
SIEM Query:
source="nagios_access.log" AND ("<script>" OR "javascript:" OR "onerror=" OR "onload=")