CVE-2020-23830
📋 TL;DR
This CSRF vulnerability in SourceCodester Stock Management System v1.0 allows attackers to change authenticated users' usernames without their consent when they visit malicious third-party sites. This can deny legitimate users future logins by changing their credentials. All users of the vulnerable system are affected.
💻 Affected Systems
- SourceCodester Stock Management System
📦 What is this software?
Stock Management System by Stock Management System Project
⚠️ Risk & Real-World Impact
Worst Case
Administrator accounts could be locked out, causing complete system unavailability and requiring database-level intervention to restore access.
Likely Case
Regular users lose access to their accounts, requiring administrator intervention to reset usernames and restore functionality.
If Mitigated
With proper CSRF protections, no unauthorized username changes occur, maintaining normal system operations.
🎯 Exploit Status
Exploitation requires the victim to be authenticated and visit a malicious site. The exploit is simple HTML/JavaScript that submits a form to changeUsername.php.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: Not available
Restart Required: No
Instructions:
No official patch exists. Consider implementing CSRF tokens in changeUsername.php or upgrading if a newer version becomes available.
🔧 Temporary Workarounds
Add CSRF Protection to changeUsername.php
allImplement CSRF tokens in the changeUsername.php endpoint to validate legitimate requests.
Edit changeUsername.php to include CSRF token generation and validation. Add token generation in form: <?php $_SESSION['csrf_token'] = bin2hex(random_bytes(32)); ?> and validation before processing: if(!hash_equals($_SESSION['csrf_token'], $_POST['csrf_token'])) { die('CSRF validation failed'); }
Disable changeUsername.php Endpoint
allTemporarily disable the vulnerable endpoint until proper fixes can be implemented.
Rename changeUsername.php to changeUsername.php.disabled or add exit(); at the beginning of the file.
🧯 If You Can't Patch
- Implement web application firewall (WAF) rules to block unauthorized POST requests to changeUsername.php
- Educate users about phishing risks and implement strict access controls to limit who can change usernames
🔍 How to Verify
Check if Vulnerable:
Check if changeUsername.php exists in the web root and lacks CSRF token validation in its source code.Check Version:
Check the system's version in its configuration files or about page, or examine file headers for version 1.0 references.Verify Fix Applied:
Test that changeUsername.php now requires a valid CSRF token and rejects requests without proper tokens.📡 Detection & Monitoring
Log Indicators:
- Multiple failed login attempts from legitimate users
- Username change requests without corresponding user actions in logs
Network Indicators:
- POST requests to changeUsername.php from unexpected referrers or without proper session tokens
SIEM Query:
source="web_logs" AND uri="/changeUsername.php" AND method="POST" AND NOT referrer CONTAINS "your-domain.com"