CVE-2023-53909
📋 TL;DR
WBCE CMS 1.6.1 contains a stored cross-site scripting vulnerability where authenticated users can upload malicious SVG files containing JavaScript. When victims access these uploaded files, the JavaScript executes in their browser context. This affects all WBCE CMS 1.6.1 installations with the media manager enabled.
💻 Affected Systems
- WBCE CMS
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal administrator session cookies, perform actions as authenticated users, deface websites, or redirect users to malicious sites.
Likely Case
Attackers with authenticated access could compromise other user accounts, steal sensitive data, or modify website content.
If Mitigated
With proper input validation and content security policies, the impact is limited to potential data leakage from the victim's session.
🎯 Exploit Status
Exploitation requires authenticated access and knowledge of the vulnerable endpoint.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.6.2 or later
Vendor Advisory: https://wbce-cms.org/
Restart Required: No
Instructions:
1. Backup your WBCE CMS installation and database. 2. Download the latest version from wbce-cms.org. 3. Replace the existing installation files with the updated version. 4. Clear browser cache and test functionality.
🔧 Temporary Workarounds
Disable SVG uploads
allModify the media manager configuration to block SVG file uploads
Edit /wbce/modules/elfinder/ef/php/connector.wbce.php to remove 'image/svg+xml' from allowed MIME types
Implement Content Security Policy
allAdd CSP headers to prevent inline script execution
Add 'Content-Security-Policy: script-src 'self'' to HTTP headers
🧯 If You Can't Patch
- Restrict media manager access to trusted administrators only
- Implement web application firewall rules to block malicious SVG uploads
🔍 How to Verify
Check if Vulnerable:
Check if you can upload an SVG file containing <script>alert('XSS')</script> to the media manager and execute it when accessedCheck Version:
Check /wbce/info.php or admin dashboard for version numberVerify Fix Applied:
Attempt to upload the same malicious SVG file after patching - it should be blocked or sanitized📡 Detection & Monitoring
Log Indicators:
- Unusual SVG file uploads to /wbce/modules/elfinder/ef/php/connector.wbce.php
- Multiple failed upload attempts with script content
Network Indicators:
- POST requests to connector.wbce.php with SVG content containing script tags
SIEM Query:
source="web_server" AND uri="/wbce/modules/elfinder/ef/php/connector.wbce.php" AND method="POST" AND content_type="image/svg+xml"