CVE-2023-6723
📋 TL;DR
CVE-2023-6723 is an unrestricted file upload vulnerability in Repbox that allows attackers to upload malicious files via the transforamationfileupload function due to insufficient file type validation. This can lead to remote code execution and full system compromise. All Repbox installations using vulnerable versions are affected.
💻 Affected Systems
- Repbox
📦 What is this software?
Repox by Europeana
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with complete control over the server, data theft, ransomware deployment, and lateral movement within the network.
Likely Case
Remote code execution leading to web shell installation, data exfiltration, and potential pivot to internal systems.
If Mitigated
File uploads blocked or sanitized, preventing malicious file execution while maintaining legitimate functionality.
🎯 Exploit Status
Unrestricted file upload vulnerabilities are commonly exploited and weaponization is likely given the high CVSS score.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check vendor advisory for specific patched version
Vendor Advisory: https://www.incibe.es/en/incibe-cert/notices/aviso/multiple-vulnerabilities-repox
Restart Required: Yes
Instructions:
1. Check the vendor advisory for patched version
2. Backup current configuration and data
3. Apply the official patch or upgrade to patched version
4. Restart the Repbox service
5. Verify the fix is working
🔧 Temporary Workarounds
Web Application Firewall Rule
allBlock file uploads to the vulnerable endpoint or restrict file types
WAF-specific configuration required
Disable Vulnerable Function
allTemporarily disable the transforamationfileupload function if not required
Configuration file modification required
🧯 If You Can't Patch
- Implement strict file upload validation at the web server level
- Isolate the Repbox instance in a restricted network segment
🔍 How to Verify
Check if Vulnerable:
Check if transforamationfileupload endpoint accepts unrestricted file uploads without proper validationCheck Version:
Check Repbox version through web interface or configuration filesVerify Fix Applied:
Test that only allowed file types can be uploaded and malicious files are rejected📡 Detection & Monitoring
Log Indicators:
- Unusual file uploads to transforamationfileupload endpoint
- Uploads of executable files or scripts
- Multiple failed upload attempts
Network Indicators:
- POST requests to transforamationfileupload with unusual file extensions
- Traffic patterns indicating file upload exploitation
SIEM Query:
source="repbox" AND (uri="*transforamationfileupload*" OR file_extension IN ("php", "jsp", "asp", "exe", "sh"))