CVE-2023-40784
📋 TL;DR
DedeCMS 5.7.102 contains an unrestricted file upload vulnerability in the module_make.php component that allows attackers to upload arbitrary files, including malicious scripts. This affects all DedeCMS installations running version 5.7.102. Attackers can exploit this to achieve remote code execution and compromise the web server.
💻 Affected Systems
- DedeCMS
📦 What is this software?
Dedecms by Dedecms
⚠️ Risk & Real-World Impact
Worst Case
Complete server compromise leading to data theft, ransomware deployment, lateral movement to internal networks, and persistent backdoor installation.
Likely Case
Webshell upload leading to website defacement, data exfiltration, and use as a pivot point for further attacks.
If Mitigated
File upload attempts blocked at WAF or detected by file integrity monitoring before execution.
🎯 Exploit Status
Simple HTTP POST request with malicious file upload to vulnerable endpoint.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 5.7.103 or later
Vendor Advisory: https://www.dedecms.com/
Restart Required: No
Instructions:
1. Backup current installation. 2. Download latest version from official DedeCMS website. 3. Replace vulnerable files with patched versions. 4. Verify uploads/dede/module_make.php has proper file validation.
🔧 Temporary Workarounds
Block vulnerable endpoint
allRestrict access to the vulnerable PHP file via web server configuration.
# Apache: RewriteRule ^uploads/dede/module_make\.php$ - [F,L]
# Nginx: location ~ ^/uploads/dede/module_make\.php$ { return 403; }
File upload restrictions
allImplement strict file upload validation in web application firewall or server configuration.
# Example mod_security rule: SecRule FILES_TMPNAMES "@rx \.(php|phtml|phar)" "id:1001,phase:2,deny"
🧯 If You Can't Patch
- Implement strict WAF rules to block file uploads to the vulnerable endpoint and monitor for exploitation attempts.
- Disable or remove the uploads/dede/module_make.php file if not required for functionality.
🔍 How to Verify
Check if Vulnerable:
Check if file exists at website_root/uploads/dede/module_make.php and test file upload functionality.Check Version:
Check DedeCMS version in /data/common.inc.php or admin panel.Verify Fix Applied:
Attempt to upload a test file with PHP extension to the endpoint - should be rejected with proper validation.📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /uploads/dede/module_make.php with file uploads
- File creation events in upload directories with PHP extensions
- Webshell execution patterns in access logs
Network Indicators:
- Unusual outbound connections from web server following file uploads
- HTTP requests with suspicious file upload parameters
SIEM Query:
source="web_logs" AND (uri="/uploads/dede/module_make.php" OR file_extension="php" AND upload_action="true")