CVE-2024-41447
📋 TL;DR
This stored XSS vulnerability in Alkacon OpenCMS v17.0 allows attackers to inject malicious scripts into the author parameter when creating or modifying articles. When other users view affected articles, the scripts execute in their browsers, potentially stealing session cookies or performing unauthorized actions. This affects all OpenCMS v17.0 installations with article creation/modification functionality.
💻 Affected Systems
- Alkacon OpenCMS
📦 What is this software?
Opencms by Alkacon
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal administrator session cookies, gain administrative access, deface websites, or redirect users to malicious sites, potentially leading to complete system compromise.
Likely Case
Attackers with article creation/modification privileges could inject scripts that steal user session cookies, leading to account takeover and unauthorized content manipulation.
If Mitigated
With proper input validation and output encoding, the payload would be sanitized and rendered harmless as plain text.
🎯 Exploit Status
Exploit requires authenticated access with article creation/modification permissions. The exploit is publicly available and relatively simple to execute.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: Not available
Restart Required: No
Instructions:
No official patch available. Consider upgrading to a newer version if available, or implement workarounds.
🔧 Temporary Workarounds
Input Validation and Output Encoding
allImplement server-side validation to sanitize the author parameter and ensure proper output encoding when displaying user input.
Content Security Policy (CSP)
allImplement a strict CSP header to prevent execution of inline scripts and restrict script sources to trusted domains only.
Add to web server configuration: Content-Security-Policy: default-src 'self'; script-src 'self'
🧯 If You Can't Patch
- Restrict article creation/modification permissions to trusted users only
- Implement web application firewall (WAF) rules to block XSS payloads in the author parameter
🔍 How to Verify
Check if Vulnerable:
Test by creating/modifying an article with a simple XSS payload in the author field (e.g., <script>alert('XSS')</script>) and check if it executes when viewing the article.Check Version:
Check OpenCMS version in administration panel or via system information files.Verify Fix Applied:
After implementing fixes, repeat the test with the same payload and verify it does not execute and appears as plain text.📡 Detection & Monitoring
Log Indicators:
- Unusual article creation/modification activity
- Author parameter containing script tags or JavaScript code
Network Indicators:
- HTTP requests with script tags in author parameter
- Unusual outbound connections from user browsers after viewing articles
SIEM Query:
web_access_logs WHERE uri CONTAINS '/opencms/' AND (params CONTAINS '<script' OR params CONTAINS 'javascript:')