CVE-2023-7321
📋 TL;DR
Nagios Log Server versions before 2.1.14 contain a stored cross-site scripting vulnerability in the Snapshots Page. Attackers can inject malicious scripts into log data that execute in victims' browsers when viewing snapshots, potentially compromising user sessions or performing actions within the application. Organizations using Nagios Log Server versions prior to 2.1.14 are affected.
💻 Affected Systems
- Nagios Log Server
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal administrator session cookies, perform actions as authenticated users, redirect users to malicious sites, or install malware through the Nagios Log Server interface.
Likely Case
Attackers with access to inject malicious log data could hijack user sessions, perform unauthorized actions within the application, or steal sensitive information displayed in the interface.
If Mitigated
With proper input validation and output encoding, the risk is limited to potential data integrity issues in log display without script execution.
🎯 Exploit Status
Exploitation requires the ability to inject malicious content into logs that Nagios Log Server processes, then requires a victim to view the affected snapshot page.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.1.14
Vendor Advisory: https://www.nagios.com/changelog/nagios-log-server-2024r1/
Restart Required: No
Instructions:
1. Backup your Nagios Log Server configuration and data. 2. Download Nagios Log Server 2.1.14 or later from the official Nagios website. 3. Follow the upgrade instructions in the Nagios documentation. 4. Verify the upgrade completed successfully.
🔧 Temporary Workarounds
Input Validation and Sanitization
allImplement strict input validation and output encoding for log data displayed in the Snapshots Page interface.
🧯 If You Can't Patch
- Restrict access to Nagios Log Server interface to trusted users only using network segmentation and access controls.
- Implement web application firewall (WAF) rules to detect and block XSS payloads in log data and web requests.
🔍 How to Verify
Check if Vulnerable:
Check the Nagios Log Server version via the web interface or by examining the installation directory. Versions below 2.1.14 are vulnerable.Check Version:
Check the web interface dashboard or examine the version file in the Nagios Log Server installation directory.Verify Fix Applied:
After upgrading, verify the version is 2.1.14 or higher and test that malicious script payloads in log data no longer execute when viewing snapshots.📡 Detection & Monitoring
Log Indicators:
- Unusual log entries containing script tags or JavaScript code patterns
- Multiple failed attempts to inject malicious payloads into logs
Network Indicators:
- Unusual outbound connections from Nagios Log Server to external domains
- Suspicious HTTP requests containing XSS payload patterns
SIEM Query:
source="nagios_log_server" AND (message="*<script>*" OR message="*javascript:*" OR message="*onerror=*" OR message="*onload=*")