CVE-2024-13993
📋 TL;DR
Nagios XI versions before 2024R1.1.2 have a reflected cross-site scripting (XSS) vulnerability on the login page when accessed with older web browsers. Attackers can craft malicious links that execute arbitrary JavaScript in victims' browsers within the Nagios XI origin. Organizations using vulnerable Nagios XI versions with legacy browser access are affected.
💻 Affected Systems
- Nagios XI
📦 What is this software?
Nagios Xi by Nagios
Nagios Xi by Nagios
Nagios Xi by Nagios
Nagios Xi by Nagios
Nagios Xi by Nagios
⚠️ Risk & Real-World Impact
Worst Case
Attacker steals session cookies or authentication tokens, leading to full Nagios XI compromise, privilege escalation, or lateral movement within the monitoring infrastructure.
Likely Case
Attacker steals session cookies to hijack authenticated sessions, potentially gaining unauthorized access to monitoring data and system configurations.
If Mitigated
With modern browsers and proper input validation, the attack fails or has limited impact due to browser XSS protections.
🎯 Exploit Status
Exploitation requires user interaction (clicking malicious link) and older browser usage; modern browsers reduce attack surface.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2024R1.1.2 or later
Vendor Advisory: https://www.nagios.com/changelog/nagios-xi/
Restart Required: No
Instructions:
1. Backup current Nagios XI configuration and data. 2. Download latest Nagios XI version from official portal. 3. Follow Nagios XI upgrade documentation for your deployment method. 4. Verify upgrade completed successfully.
🔧 Temporary Workarounds
Browser Policy Enforcement
allEnforce use of modern browsers with XSS protection enabled and disable legacy browser access to Nagios XI.
Web Application Firewall Rules
allDeploy WAF rules to detect and block XSS payloads targeting the login page parameters.
🧯 If You Can't Patch
- Implement strict Content Security Policy (CSP) headers to restrict script execution sources.
- Deploy network segmentation to isolate Nagios XI from user workstations and restrict access to trusted networks only.
🔍 How to Verify
Check if Vulnerable:
Check Nagios XI version via Admin > System Config > About page or run: grep 'nagiosxi_version' /usr/local/nagiosxi/var/xiversionCheck Version:
grep 'nagiosxi_version' /usr/local/nagiosxi/var/xiversionVerify Fix Applied:
Verify version is 2024R1.1.2 or higher and test login page with XSS payloads in older browser simulation.📡 Detection & Monitoring
Log Indicators:
- Unusual login attempts with suspicious parameters containing script tags or JavaScript code in web server logs.
- Multiple failed login attempts from single IP with XSS payload patterns.
Network Indicators:
- HTTP requests to login page with encoded script tags or JavaScript in query parameters.
- Traffic patterns showing users redirected to Nagios XI login with unusual referral URLs.
SIEM Query:
source="web_server_logs" url="*login*" (param="*<script>*" OR param="*javascript:*" OR param="*onerror=*" OR param="*onload=*")