CVE-2025-56295
📋 TL;DR
Computer Laboratory System 1.0 has an unrestricted file upload vulnerability that allows authenticated staff users to upload PHP backdoor files through the avatar modification feature. This enables attackers to execute arbitrary code and gain server control. Only systems running this specific software version are affected.
💻 Affected Systems
- Computer Laboratory System
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full server compromise leading to data theft, ransomware deployment, or use as attack launchpad
Likely Case
Web shell installation allowing persistent access, data exfiltration, and lateral movement
If Mitigated
Limited impact with proper file upload restrictions and web application firewalls
🎯 Exploit Status
Exploit requires staff credentials; GitHub repository contains proof-of-concept
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: http://code-projects.com
Restart Required: No
Instructions:
No official patch available. Consider upgrading to newer version if exists or implementing workarounds.
🔧 Temporary Workarounds
Restrict File Upload Extensions
allConfigure web server to block PHP file uploads through avatar feature
# In .htaccess for Apache:
<FilesMatch "\.(php|php5|php7|phtml)$">
Order Allow,Deny
Deny from all
</FilesMatch>
# In nginx config:
location ~ \.php$ {
deny all;
}
Implement File Type Validation
allAdd server-side validation to only allow image file types (jpg, png, gif)
# Example PHP validation:
$allowed_types = ['image/jpeg', 'image/png', 'image/gif'];
if(!in_array($_FILES['avatar']['type'], $allowed_types)) {
die('Invalid file type');
}
🧯 If You Can't Patch
- Disable avatar upload functionality completely
- Implement Web Application Firewall (WAF) rules to block PHP file uploads
🔍 How to Verify
Check if Vulnerable:
Attempt to upload a PHP file through staff avatar upload feature and check if it executesCheck Version:
Check software version in admin panel or configuration filesVerify Fix Applied:
Test that PHP files cannot be uploaded or executed via avatar upload📡 Detection & Monitoring
Log Indicators:
- PHP file uploads via avatar endpoints
- Unusual file uploads from staff accounts
- Web shell connection attempts
Network Indicators:
- POST requests with PHP file uploads to avatar endpoints
- Suspicious outbound connections from web server
SIEM Query:
source="web_logs" AND (uri="*avatar*" AND file_extension="php")