CVE-2023-53884
📋 TL;DR
Webedition CMS v2.9.8.8 contains a stored cross-site scripting vulnerability where authenticated users can upload malicious SVG files containing JavaScript. When other users view these uploaded files, the embedded scripts execute in their browser context, potentially stealing session cookies or performing actions on their behalf. This affects all Webedition CMS installations running the vulnerable version.
💻 Affected Systems
- Webedition CMS
📦 What is this software?
Webedition Cms by Webedition
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal administrator session cookies, take over admin accounts, deface websites, or distribute malware to site visitors through the compromised CMS.
Likely Case
Authenticated users with upload privileges could perform session hijacking against other users, steal credentials, or manipulate website content.
If Mitigated
With proper input validation and content security policies, the impact is limited to potential data leakage from users who view malicious files.
🎯 Exploit Status
Exploit requires authenticated access but is trivial to execute once authenticated. Public exploit code is available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.webedition.org/
Restart Required: No
Instructions:
Check vendor website for security updates. No official patch is documented as of analysis date.
🔧 Temporary Workarounds
Disable SVG Uploads
allConfigure Webedition CMS to block SVG file uploads through the media upload feature.
Modify CMS configuration to remove 'svg' from allowed file types in upload settings
Implement Content Security Policy
allAdd CSP headers to prevent inline script execution from uploaded files.
Add 'Content-Security-Policy: script-src 'self'' header to web server configuration
🧯 If You Can't Patch
- Restrict media upload permissions to trusted administrators only
- Implement web application firewall rules to block SVG files containing JavaScript patterns
🔍 How to Verify
Check if Vulnerable:
Test if authenticated users can upload SVG files containing <script> tags and execute JavaScript when viewedCheck Version:
Check Webedition CMS admin panel or version file for '2.9.8.8'Verify Fix Applied:
Attempt to upload malicious SVG file and verify JavaScript does not execute when file is accessed📡 Detection & Monitoring
Log Indicators:
- Unusual SVG file uploads
- Multiple failed upload attempts with SVG files
- Admin panel access from unusual locations following SVG uploads
Network Indicators:
- HTTP POST requests to media upload endpoints with SVG content
- Requests to uploaded SVG files followed by suspicious outbound connections
SIEM Query:
source="webedition_logs" AND (file_extension="svg" OR mime_type="image/svg+xml")