CVE-2011-10038
📋 TL;DR
This cross-site scripting vulnerability in Nagios XI allows attackers to inject malicious scripts into the recurring downtime web interface. When exploited, these scripts execute in victims' browsers, potentially stealing session cookies or performing actions as authenticated users. Organizations running Nagios XI versions before 2011R1.9 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
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 administrator session cookies, gains full administrative access to Nagios XI, and potentially compromises the monitoring infrastructure or uses it as a pivot point to internal systems.
Likely Case
Attacker steals user session cookies, gains unauthorized access to monitoring data, or performs limited administrative actions depending on victim's privileges.
If Mitigated
Script execution is blocked by browser security features or CSP headers, limiting impact to minor UI disruption.
🎯 Exploit Status
Exploitation requires authenticated access and social engineering to trick users into interacting with malicious payloads.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2011R1.9 or later
Vendor Advisory: https://www.nagios.com/changelog/nagios-xi/
Restart Required: No
Instructions:
1. Log into Nagios XI web interface as administrator. 2. Navigate to Admin > Check for Updates. 3. Follow the upgrade wizard to install version 2011R1.9 or later. 4. Verify the update completed successfully.
🔧 Temporary Workarounds
Input Validation Enhancement
allImplement additional input validation for the recurring downtime script parameters
Content Security Policy
allImplement strict CSP headers to limit script execution
🧯 If You Can't Patch
- Restrict access to Nagios XI web interface to trusted users only
- Implement web application firewall rules to detect and block XSS payloads
🔍 How to Verify
Check if Vulnerable:
Check Nagios XI version via Admin > System Status or by examining /usr/local/nagiosxi/var/xiversion fileCheck Version:
cat /usr/local/nagiosxi/var/xiversionVerify Fix Applied:
Confirm version is 2011R1.9 or later and test recurring downtime functionality with safe test payloads📡 Detection & Monitoring
Log Indicators:
- Unusual recurring downtime entries
- Suspicious script-like content in web logs
Network Indicators:
- HTTP requests with script tags or JavaScript in recurring downtime parameters
SIEM Query:
web_access_logs WHERE url_path CONTAINS 'recurring_downtime' AND (request_body CONTAINS '<script' OR request_body CONTAINS 'javascript:')