CVE-2023-53690
📋 TL;DR
Nagios Fusion versions before 4.2.0 have a stored XSS vulnerability in LDAP/AD authentication configuration. Attackers with LDAP/AD configuration access can inject malicious JavaScript that executes in other administrators' browsers when viewing the affected page. This affects Nagios Fusion administrators who use LDAP/AD authentication integration.
💻 Affected Systems
- Nagios Fusion
📦 What is this software?
Fusion by Nagios
⚠️ Risk & Real-World Impact
Worst Case
An attacker with LDAP/AD configuration privileges could steal administrator session cookies, perform actions as authenticated users, or redirect to malicious sites, potentially leading to full system compromise.
Likely Case
Attackers with LDAP/AD configuration access could steal session tokens or credentials from administrators viewing the affected configuration page, leading to unauthorized administrative access.
If Mitigated
With proper access controls limiting who can configure LDAP/AD servers, the attack surface is reduced to authorized administrators only.
🎯 Exploit Status
Requires authentication with LDAP/AD configuration privileges. The payload is stored and executes when other users view the configuration page.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 4.2.0
Vendor Advisory: https://www.nagios.com/changelog/nagios-fusion/
Restart Required: No
Instructions:
1. Backup current configuration. 2. Download Nagios Fusion 4.2.0 from Nagios website. 3. Follow upgrade instructions in documentation. 4. Verify upgrade completed successfully.
🔧 Temporary Workarounds
Restrict LDAP/AD Configuration Access
allLimit administrative access to only trusted users who need to configure LDAP/AD authentication servers.
Input Validation via Web Application Firewall
allDeploy WAF rules to sanitize input in LDAP/AD configuration endpoints.
🧯 If You Can't Patch
- Implement strict access controls to limit who can configure LDAP/AD authentication servers.
- Monitor and audit LDAP/AD configuration changes for suspicious activity.
🔍 How to Verify
Check if Vulnerable:
Check Nagios Fusion version via web interface or command line. If version is below 4.2.0 and LDAP/AD authentication is configured, system is vulnerable.Check Version:
cat /usr/local/nagiosfusion/var/fusion-version.txtVerify Fix Applied:
After upgrading to 4.2.0, verify version shows 4.2.0 or higher and test LDAP/AD configuration input sanitization.📡 Detection & Monitoring
Log Indicators:
- Unusual LDAP/AD configuration changes
- JavaScript payloads in configuration logs
- Multiple failed authentication attempts followed by configuration changes
Network Indicators:
- Unexpected outbound connections from Nagios Fusion server after viewing configuration pages
SIEM Query:
source="nagios_fusion" AND (event="ldap_config_change" OR event="ad_config_change") AND (message="*<script>*" OR message="*javascript:*")