CVE-2023-40933
📋 TL;DR
This SQL injection vulnerability in Nagios XI allows authenticated attackers with announcement banner configuration privileges to execute arbitrary SQL commands. Attackers could potentially read, modify, or delete database contents, affecting Nagios XI v5.11.1 and below installations.
💻 Affected Systems
- Nagios XI
📦 What is this software?
Nagios Xi by Nagios
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the Nagios XI database leading to credential theft, system takeover, and lateral movement to other systems
Likely Case
Data exfiltration, privilege escalation, and manipulation of monitoring data
If Mitigated
Limited impact due to proper access controls and network segmentation
🎯 Exploit Status
Exploitation requires authenticated access but SQL injection is straightforward once authenticated
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v5.11.2 or later
Vendor Advisory: https://www.nagios.com/products/security/
Restart Required: Yes
Instructions:
1. Backup current configuration and database. 2. Download latest Nagios XI version from official site. 3. Follow Nagios XI upgrade documentation. 4. Restart Nagios XI services.
🔧 Temporary Workarounds
Remove announcement banner privileges
allTemporarily remove announcement banner configuration privileges from all users
# Review and modify user permissions in Nagios XI admin interface
Network segmentation
allRestrict access to Nagios XI admin interface to trusted networks only
# Configure firewall rules to limit access to Nagios XI port
🧯 If You Can't Patch
- Implement strict access controls and limit users with announcement banner privileges
- Deploy web application firewall with SQL injection protection rules
🔍 How to Verify
Check if Vulnerable:
Check Nagios XI version via admin interface or command lineCheck Version:
grep 'nagios_version' /usr/local/nagiosxi/var/xiversionVerify Fix Applied:
Verify version is v5.11.2 or later and test announcement banner functionality📡 Detection & Monitoring
Log Indicators:
- Unusual SQL queries in database logs
- Multiple failed login attempts followed by announcement banner access
Network Indicators:
- Unusual database connections from Nagios XI server
- SQL error messages in HTTP responses
SIEM Query:
source="nagios" AND ("update_banner_message" OR "SQL syntax" OR "announcement banner")