CVE-2024-40731
📋 TL;DR
This CVE describes a cross-site scripting (XSS) vulnerability in NetBox v4.0.3 that allows attackers to inject malicious scripts into the Name parameter when editing rear ports. This affects all NetBox v4.0.3 installations with web interface access, 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 redirect users to malicious sites, potentially leading to full system compromise.
Likely Case
Attackers would typically steal session cookies or credentials from authenticated users, gaining unauthorized access to the NetBox system.
If Mitigated
With proper input validation and output encoding, the attack would be prevented, and only sanitized data would be displayed.
🎯 Exploit Status
Exploitation requires authentication to access the edit endpoint, but the XSS payload execution occurs when other users view the malicious content.
🛠️ 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 v4.0.4 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.
# Requires code modification to add input sanitization
Web Application Firewall (WAF)
allDeploy a WAF with XSS protection rules to block malicious payloads.
# Configure WAF rules to block script tags and JavaScript in Name parameter
🧯 If You Can't Patch
- Restrict access to the NetBox web interface using network segmentation and firewall rules.
- Implement Content Security Policy (CSP) headers to mitigate XSS impact.
🔍 How to Verify
Check if Vulnerable:
Check if NetBox version is exactly v4.0.3 by examining the version in the web interface footer or running: 'python -c "import netbox; print(netbox.__version__)"'Check Version:
python -c "import netbox; print('NetBox version:', netbox.__version__)"Verify Fix Applied:
Verify the version is v4.0.4 or later and test the Name parameter with basic XSS payloads like '<script>alert(1)</script>' to ensure they are properly sanitized.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /dcim/rear-ports/*/edit/ with script tags or JavaScript in parameters
- Multiple failed login attempts followed by successful authentication and edit operations
Network Indicators:
- HTTP requests containing <script> tags or JavaScript code in the Name parameter
- Outbound connections to suspicious domains from NetBox server
SIEM Query:
source="netbox.log" AND (uri_path="/dcim/rear-ports/*/edit/" AND (param_name="name" AND param_value MATCHES "(?i)<script|javascript:"))