CVE-2023-7316
📋 TL;DR
Nagios XI versions before 2024R1 contain a cross-site scripting vulnerability in the Graph Explorer component. Insufficient input validation allows attackers to inject malicious scripts that execute in victims' browsers when viewing manipulated graphs. This affects all Nagios XI administrators and users who access the vulnerable interface.
💻 Affected Systems
- Nagios XI
📦 What is this software?
Nagios Xi by Nagios
⚠️ Risk & Real-World Impact
Worst Case
Attacker steals administrator session cookies, gains full administrative access to Nagios XI, and potentially compromises the entire monitoring infrastructure and monitored systems.
Likely Case
Attacker steals user session tokens, performs unauthorized actions within Nagios XI, or redirects users to malicious sites.
If Mitigated
Script execution blocked by CSP headers or browser XSS filters, limiting impact to minor UI disruption.
🎯 Exploit Status
Exploitation requires the attacker to craft malicious input that gets rendered in the Graph Explorer. Victim must be authenticated and view the manipulated graph.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2024R1 or later
Vendor Advisory: https://www.nagios.com/changelog/nagios-xi/
Restart Required: No
Instructions:
1. Backup current Nagios XI configuration. 2. Download Nagios XI 2024R1 or later from Nagios customer portal. 3. Follow Nagios XI upgrade documentation. 4. Verify successful upgrade and test functionality.
🔧 Temporary Workarounds
Input Validation Enhancement
allImplement additional input validation and output encoding for Graph Explorer parameters
Not applicable - requires code modification
Content Security Policy
allImplement strict CSP headers to block inline script execution
Add 'Content-Security-Policy: script-src 'self'' to web server configuration
🧯 If You Can't Patch
- Restrict access to Nagios XI to trusted networks only using firewall rules
- Implement web application firewall (WAF) rules to detect and block XSS payloads
🔍 How to Verify
Check if Vulnerable:
Check Nagios XI version via Admin > System Config > About. If version is earlier than 2024R1, system is vulnerable.Check Version:
grep 'nagiosxi_version' /usr/local/nagiosxi/var/xiversionVerify Fix Applied:
Verify version is 2024R1 or later. Test Graph Explorer functionality with various inputs to ensure proper sanitization.📡 Detection & Monitoring
Log Indicators:
- Unusual Graph Explorer parameter values containing script tags or JavaScript
- Multiple failed Graph Explorer requests with suspicious payloads
Network Indicators:
- HTTP requests to Graph Explorer with encoded script payloads in parameters
SIEM Query:
source="nagios_access.log" AND uri_path="/nagiosxi/includes/components/graphexplorer/" AND (query="*<script*" OR query="*javascript:*")