CVE-2025-47939
📋 TL;DR
This vulnerability in TYPO3's file management module allows backend users to upload potentially harmful files like executables or files with mismatched extensions/MIME types. While these files aren't directly executable via web server, they can trigger security scanners and affect site availability/reputation. Affects TYPO3 versions 9.0.0 through specific ELTS/LTS versions before the patches.
💻 Affected Systems
- TYPO3 CMS
📦 What is this software?
Typo3 by Typo3
Typo3 by Typo3
Typo3 by Typo3
Typo3 by Typo3
Typo3 by Typo3
⚠️ Risk & Real-World Impact
Worst Case
Malicious files uploaded could trigger security scanners to block entire website access, causing complete service disruption and reputational damage.
Likely Case
Accidental upload of suspicious files triggers false positives in security scanners, causing temporary access issues for some users.
If Mitigated
With proper file validation and monitoring, impact is limited to minor administrative overhead for file review.
🎯 Exploit Status
Exploitation requires authenticated backend user access; simple file upload operation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 9.5.51 ELTS, 10.4.50 ELTS, 11.5.44 ELTS, 12.4.31 LTS, or 13.4.12 LTS
Vendor Advisory: https://typo3.org/security/advisory/typo3-core-sa-2025-014
Restart Required: No
Instructions:
1. Identify your TYPO3 version. 2. Update to the appropriate patched version via Composer or manual update. 3. Clear TYPO3 caches. 4. Verify file upload restrictions are now enforced.
🔧 Temporary Workarounds
Implement custom file upload restrictions
allAdd custom validation to restrict file uploads in TYPO3 backend
Add custom TypoScript or PHP validation in your extension
Restrict backend user file upload permissions
allLimit which backend users can upload files through TYPO3 permissions
Configure in TYPO3 backend: Admin Tools > Access > User/Group permissions
🧯 If You Can't Patch
- Implement web application firewall rules to block suspicious file uploads
- Enable strict file validation in web server configuration (e.g., .htaccess, nginx rules)
🔍 How to Verify
Check if Vulnerable:
Check TYPO3 version in backend dashboard or via composer show typo3/cms-coreCheck Version:
composer show typo3/cms-core | grep versionVerify Fix Applied:
Attempt to upload restricted file type (e.g., .exe) in backend - should be blocked📡 Detection & Monitoring
Log Indicators:
- File upload attempts with suspicious extensions in TYPO3 logs
- Security scanner alerts for uploaded files
Network Indicators:
- Increased file upload traffic to TYPO3 backend
- External scanner requests to uploaded files
SIEM Query:
source="typo3.log" AND ("file upload" OR "upload.*failed") AND (extension="exe" OR extension="bat" OR extension="sh")