CVE-2024-40727
📋 TL;DR
This CVE describes a cross-site scripting (XSS) vulnerability in NetBox v4.0.3 where attackers can inject malicious scripts into the Name parameter when adding console server ports. This allows execution of arbitrary web scripts or HTML in victims' browsers. Organizations running vulnerable NetBox instances are affected.
💻 Affected Systems
- NetBox
📦 What is this software?
Netbox by Netbox
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal session cookies, perform actions as authenticated users, deface the application, or redirect users to malicious sites, potentially leading to full account compromise.
Likely Case
Attackers with access to the console server port creation interface could inject persistent XSS payloads that execute when other users view those entries, enabling session hijacking or credential theft.
If Mitigated
With proper input validation and output encoding, the payload would be rendered harmless as text rather than executable code.
🎯 Exploit Status
Exploitation requires access to create console server ports (typically authenticated users). The GitHub reference shows proof-of-concept payloads.
🛠️ 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
WAF Rule
allDeploy a web application firewall rule to block XSS payloads in the Name parameter
🧯 If You Can't Patch
- Restrict access to the /dcim/console-server-ports/add/ endpoint to only trusted administrators
- Implement Content Security Policy (CSP) headers to mitigate XSS impact
🔍 How to Verify
Check if Vulnerable:
Check if NetBox version is 4.0.3 by visiting /api/ or checking the admin interface footerCheck Version:
python -c "import netbox; print(netbox.__version__)"Verify Fix Applied:
Verify NetBox version is 4.0.4 or later and test XSS payload injection in the Name field at /dcim/console-server-ports/add/📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /dcim/console-server-ports/add/ with script tags or JavaScript in parameters
- Multiple failed XSS attempts in web server logs
Network Indicators:
- HTTP requests containing <script> tags or JavaScript in the 'name' parameter
SIEM Query:
source="web_logs" AND uri_path="/dcim/console-server-ports/add/" AND (param_name="name" AND param_value MATCHES "(?i)<script|javascript:")