CVE-2021-25211
📋 TL;DR
CVE-2021-25211 is an arbitrary file upload vulnerability in SourceCodester Ordering System v1.0 that allows attackers to upload malicious files to the server via the edit.php endpoint. This enables remote code execution, potentially giving attackers full control of affected systems. Anyone running the vulnerable version of this ordering system is affected.
💻 Affected Systems
- SourceCodester Ordering System
📦 What is this software?
Online Ordering System by Online Ordering System Project
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining administrative privileges, data theft, ransomware deployment, and use as pivot point for lateral movement.
Likely Case
Webshell deployment leading to data exfiltration, credential harvesting, and backdoor persistence on the server.
If Mitigated
Attack blocked at web application firewall level with no file uploads reaching the vulnerable endpoint.
🎯 Exploit Status
Exploitation requires only HTTP POST request with malicious file upload to the vulnerable endpoint. Public proof-of-concept code exists in GitHub repositories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: No
Instructions:
No official patch available. Consider migrating to alternative software or implementing workarounds.
🔧 Temporary Workarounds
File Upload Restriction
allImplement strict file upload validation in web server configuration or application layer
# Apache .htaccess example
<Files "edit.php">
SetEnvIf Request_URI "^/ordering/admin/products/edit\.php$" block_upload
Deny from env=block_upload
</Files>
# Nginx location block example
location ~* /ordering/admin/products/edit\.php$ {
deny all;
}
File Extension Validation
allAdd server-side validation to only allow specific safe file extensions
# PHP validation example
$allowed_extensions = array('jpg', 'jpeg', 'png', 'gif');
$file_extension = strtolower(pathinfo($_FILES['file']['name'], PATHINFO_EXTENSION));
if (!in_array($file_extension, $allowed_extensions)) {
die('Invalid file type');
}
🧯 If You Can't Patch
- Block access to /ordering/admin/products/edit.php at network perimeter or web application firewall
- Implement strict file upload monitoring and alerting for unexpected file types in upload directories
🔍 How to Verify
Check if Vulnerable:
Check if ordering/admin/products/edit.php exists and accepts file uploads without proper validation. Test by attempting to upload a file with PHP extension.Check Version:
Check source code or documentation for version information. Look for 'v1.0' references in files or database.Verify Fix Applied:
Attempt to upload a file with .php extension to the vulnerable endpoint. Successful upload indicates still vulnerable.📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /ordering/admin/products/edit.php with file uploads
- Files with .php, .phtml, or other executable extensions appearing in upload directories
- Unusual file creation in web-accessible directories
Network Indicators:
- POST requests to vulnerable endpoint with Content-Type: multipart/form-data
- Unexpected file uploads to admin interface
SIEM Query:
source="web_logs" AND (uri="/ordering/admin/products/edit.php" AND method="POST" AND content_type="multipart/form-data")