CVE-2020-27956
📋 TL;DR
This vulnerability allows attackers to upload malicious PHP files through the car rental management system's image upload feature, leading to remote code execution. Any organization using SourceCodester Car Rental Management System 1.0 is affected, particularly those with internet-facing installations.
💻 Affected Systems
- SourceCodester Car Rental Management System
📦 What is this software?
Car Rental Management System by Car Rental Management System Project
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to execute arbitrary code, steal data, install backdoors, or pivot to other systems.
Likely Case
Web server compromise leading to data theft, defacement, or use as part of a botnet.
If Mitigated
Limited impact if proper file upload validation and web server permissions are configured.
🎯 Exploit Status
Exploit requires admin credentials but is trivial to execute once authenticated.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: No
Instructions:
No official patch available. Consider replacing with alternative software or implementing workarounds.
🔧 Temporary Workarounds
Restrict PHP file uploads
allAdd server-side validation to reject .php file uploads in the upload component
Modify upload validation in admin/index.php?page=manage_car to check file extensions
Restrict upload directory execution
linuxPrevent PHP execution in the uploads directory
Add to .htaccess in admin/assets/uploads/: php_flag engine off
Or add to nginx config: location ~* \.php$ { deny all; }
🧯 If You Can't Patch
- Remove or restrict admin access to the vulnerable system
- Implement WAF rules to block .php file uploads to the vulnerable endpoint
🔍 How to Verify
Check if Vulnerable:
Attempt to upload a .php file via admin/index.php?page=manage_car and check if it's saved to admin/assets/uploads/Check Version:
Check system version in admin panel or source code filesVerify Fix Applied:
Verify .php files cannot be uploaded or cannot be executed from uploads directory📡 Detection & Monitoring
Log Indicators:
- POST requests to admin/index.php?page=manage_car with .php file uploads
- File creation in admin/assets/uploads/ with .php extension
Network Indicators:
- HTTP POST requests with file uploads to vulnerable endpoint
- Subsequent requests to uploaded PHP files
SIEM Query:
source="web_logs" AND uri="/admin/index.php" AND params="page=manage_car" AND method="POST" AND file_extension="php"