CVE-2022-27426
📋 TL;DR
This Server-Side Request Forgery vulnerability in Chamilo LMS allows attackers to make the server send requests to internal network resources and execute arbitrary system commands via malicious Phar file uploads. It affects Chamilo LMS installations running vulnerable versions, potentially compromising the entire server and internal network.
💻 Affected Systems
- Chamilo LMS
📦 What is this software?
Chamilo Lms by Chamilo
⚠️ Risk & Real-World Impact
Worst Case
Full server compromise leading to data exfiltration, lateral movement within internal networks, ransomware deployment, and complete system takeover.
Likely Case
Internal network reconnaissance, sensitive data exposure, and potential command execution on the vulnerable server.
If Mitigated
Limited to SSRF capabilities without command execution if Phar file uploads are blocked.
🎯 Exploit Status
Exploitation requires file upload access, which may require authentication depending on configuration.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v1.11.14 and later
Vendor Advisory: https://support.chamilo.org/projects/1/wiki/Security_issues
Restart Required: No
Instructions:
1. Backup your Chamilo installation and database. 2. Download the latest version from the official Chamilo website. 3. Replace the vulnerable files with patched versions. 4. Clear application cache. 5. Verify functionality.
🔧 Temporary Workarounds
Disable Phar file uploads
allBlock uploads of Phar files through web server configuration or application filtering
# Apache: Add to .htaccess
<FilesMatch "\.phar$">
Require all denied
</FilesMatch>
# Nginx: Add to server block
location ~ \.phar$ {
deny all;
}
Restrict file upload permissions
allLimit file upload functionality to authenticated administrators only
🧯 If You Can't Patch
- Implement strict network segmentation to isolate Chamilo server from sensitive internal resources
- Deploy web application firewall with SSRF and file upload protection rules
🔍 How to Verify
Check if Vulnerable:
Check Chamilo version in administration panel or main.inc.php configuration fileCheck Version:
grep -r "chamilo_version" /path/to/chamilo/ or check admin panelVerify Fix Applied:
Verify version is 1.11.14 or later and test file upload functionality with Phar files📡 Detection & Monitoring
Log Indicators:
- Unusual file uploads with .phar extension
- Outbound requests to internal IP ranges from Chamilo server
- Suspicious system command execution in web server logs
Network Indicators:
- Chamilo server making unexpected internal network requests
- Outbound connections to unusual ports from web server
SIEM Query:
source="web_logs" AND (uri="*upload*" AND file_extension="phar") OR (src_ip="chamilo_server" AND dst_ip="internal_range")