CVE-2024-40737
📋 TL;DR
A stored cross-site scripting (XSS) vulnerability in NetBox v4.0.3 allows authenticated attackers to inject malicious scripts into the Name parameter when adding console ports. This vulnerability affects all NetBox instances running the vulnerable version, potentially compromising user sessions and data.
💻 Affected Systems
- NetBox
📦 What is this software?
Netbox by Netbox
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal administrator credentials, hijack user sessions, deface the application, or perform actions on behalf of authenticated users, potentially leading to full system compromise.
Likely Case
Attackers with authenticated access could steal session cookies, redirect users to malicious sites, or perform limited unauthorized actions within the application.
If Mitigated
With proper input validation and output encoding, the attack would be prevented, and impact would be limited to failed exploitation attempts.
🎯 Exploit Status
Exploitation requires authenticated access. The vulnerability is in a web form parameter with public proof-of-concept available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v4.0.4 or later
Vendor Advisory: https://github.com/netbox-community/netbox/releases
Restart Required: Yes
Instructions:
1. Backup your NetBox database and configuration. 2. Update NetBox to version 4.0.4 or later using pip: 'pip install --upgrade netbox'. 3. Run database migrations: 'python manage.py migrate'. 4. Restart the NetBox service.
🔧 Temporary Workarounds
Input Validation Filter
allImplement server-side input validation to sanitize the Name parameter before processing.
Implement custom validation in the console port creation view to strip or escape HTML/JavaScript tags
Web Application Firewall (WAF)
allConfigure WAF rules to block XSS payloads in the Name parameter.
Add WAF rule: Block requests containing <script>, javascript:, or common XSS patterns in the Name parameter
🧯 If You Can't Patch
- Restrict access to the /dcim/console-ports/add endpoint to only trusted administrators
- Implement Content Security Policy (CSP) headers to mitigate script execution
🔍 How to Verify
Check if Vulnerable:
Test by attempting to inject a simple XSS payload like '<script>alert(1)</script>' into the Name field when adding a console port. If the script executes when viewing the console port, the system is vulnerable.Check Version:
python -c "import netbox; print(netbox.__version__)"Verify Fix Applied:
After patching, attempt the same XSS payload injection. The input should be properly sanitized and no script execution should occur.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /dcim/console-ports/add with script tags or JavaScript in parameters
- Multiple failed login attempts followed by console port creation
Network Indicators:
- HTTP requests containing <script> tags or JavaScript code in the Name parameter
- Unusual outbound connections from NetBox server after console port creation
SIEM Query:
source="netbox.log" AND (uri_path="/dcim/console-ports/add" AND (param_name="name" AND param_value CONTAINS "<script>" OR param_value CONTAINS "javascript:"))