CVE-2018-25158
📋 TL;DR
CVE-2018-25158 is an arbitrary file upload vulnerability in Chamilo LMS that allows authenticated users to upload PHP files disguised as images, then rename and execute them for remote code execution. This affects Chamilo LMS installations with the elfinder filemanager module enabled. Attackers with valid user credentials can compromise the entire system.
💻 Affected Systems
- Chamilo LMS
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining complete control over the server, accessing sensitive data, installing backdoors, and pivoting to other systems.
Likely Case
Unauthorized file upload leading to web shell installation, data theft, and potential lateral movement within the network.
If Mitigated
Limited impact with proper file upload validation and execution restrictions preventing successful exploitation.
🎯 Exploit Status
Exploit requires authenticated user credentials. Attack involves uploading files with image headers then renaming to .php extension.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.11.10 and later
Vendor Advisory: https://github.com/chamilo/chamilo-lms/security/advisories
Restart Required: No
Instructions:
1. Backup your installation. 2. Update to Chamilo LMS 1.11.10 or later. 3. Verify the update completed successfully. 4. Clear application cache if needed.
🔧 Temporary Workarounds
Disable elfinder filemanager
linuxTemporarily disable the vulnerable elfinder module to prevent exploitation
# Remove or rename elfinder directory
mv /path/to/chamilo/main/inc/lib/elfinder /path/to/chamilo/main/inc/lib/elfinder.disabled
Restrict file upload extensions
allConfigure web server to block .php file execution in upload directories
# Apache .htaccess example
<FilesMatch "\.(php|php5|php7|phtml)$">
Order Allow,Deny
Deny from all
</FilesMatch>
🧯 If You Can't Patch
- Implement strict file upload validation that checks both file extension and MIME type
- Configure web application firewall to block requests containing suspicious file upload patterns
🔍 How to Verify
Check if Vulnerable:
Check if Chamilo version is 1.11.8 or earlier and elfinder module is present in main/inc/lib/ directoryCheck Version:
grep -r "version.*1\.11\." /path/to/chamilo/configuration.phpVerify Fix Applied:
Verify Chamilo version is 1.11.10 or later and test file upload functionality with PHP files📡 Detection & Monitoring
Log Indicators:
- Multiple file upload attempts with .php extensions
- Files being renamed from image extensions to .php
- Unusual POST requests to upload endpoints
Network Indicators:
- HTTP POST requests to /main/inc/lib/elfinder/connector.php with file uploads
- Requests accessing uploaded .php files
SIEM Query:
source="web_logs" AND (uri_path="*elfinder*connector*" AND method="POST") OR (uri_path="*.php" AND referer="*elfinder*")