CVE-2024-26503
📋 TL;DR
This vulnerability allows attackers to upload malicious files to the certbadge.php endpoint in Open eClass, potentially leading to remote code execution. It affects Open eClass versions 3.15 and earlier. Organizations using vulnerable versions are at risk of complete system compromise.
💻 Affected Systems
- Greek Universities Network Open eClass
📦 What is this software?
Openeclass by Openeclass
⚠️ Risk & Real-World Impact
Worst Case
Complete system takeover with administrative privileges, data exfiltration, ransomware deployment, and lateral movement across the network.
Likely Case
Webshell deployment leading to persistent access, data theft, and further exploitation of the server and connected systems.
If Mitigated
Limited impact with proper file upload restrictions, web application firewalls, and network segmentation in place.
🎯 Exploit Status
Simple HTTP POST request with crafted file upload to certbadge.php endpoint.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v3.16 or later
Vendor Advisory: https://www.openeclass.org/
Restart Required: No
Instructions:
1. Backup your Open eClass installation and database. 2. Download the latest version from the official repository. 3. Replace the vulnerable files with patched versions. 4. Verify the certbadge.php endpoint now validates file uploads.
🔧 Temporary Workarounds
Block certbadge.php endpoint
allTemporarily block access to the vulnerable endpoint using web server configuration.
# Apache: RewriteRule ^certbadge\.php$ - [F]
# Nginx: location ~ /certbadge\.php$ { deny all; }
Implement file upload restrictions
linuxConfigure web application firewall to block malicious file uploads.
# ModSecurity rule: SecRule FILES_TMPNAMES "@rx \.(php|phtml|phar)" "id:1001,phase:2,deny"
🧯 If You Can't Patch
- Implement strict network segmentation to isolate the Open eClass server from critical systems.
- Deploy a web application firewall with specific rules to block file uploads to certbadge.php.
🔍 How to Verify
Check if Vulnerable:
Check if Open eClass version is 3.15 or earlier and if certbadge.php accepts file uploads without validation.Check Version:
grep -r "version" /path/to/openeclass/includes/constants.php | grep -o "[0-9]\.[0-9][0-9]"Verify Fix Applied:
Test file upload to certbadge.php endpoint - it should reject malicious file types and return appropriate error messages.📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to certbadge.php with file uploads
- Unusual file creation in web directories (e.g., .php files in upload folders)
- System commands executed from web user context
Network Indicators:
- Outbound connections from web server to unknown IPs
- Unusual traffic patterns from certbadge.php endpoint
SIEM Query:
source="web_server" AND (url="*certbadge.php*" AND method="POST") AND (file_extension="php" OR file_extension="phtml")