CVE-2020-24940
📋 TL;DR
This vulnerability in Laravel allows attackers to bypass mass assignment protection by manipulating table names in database queries, potentially saving unvalidated data to the database. It affects Laravel applications using mass assignment features without proper validation. Developers using affected Laravel versions are at risk.
💻 Affected Systems
- Laravel
📦 What is this software?
Laravel by Laravel
Laravel by Laravel
⚠️ Risk & Real-World Impact
Worst Case
Attackers could inject malicious data into database tables, potentially leading to data corruption, privilege escalation, or remote code execution depending on application logic.
Likely Case
Data integrity compromise where attackers can modify database records they shouldn't have access to, potentially altering application behavior or user data.
If Mitigated
Limited impact if proper input validation and authorization checks are implemented at application layer beyond Laravel's mass assignment protection.
🎯 Exploit Status
Exploitation requires understanding of Laravel's mass assignment feature and application-specific table structures. Attackers need some level of access to submit data.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Laravel 6.18.34, Laravel 7.23.2
Vendor Advisory: https://blog.laravel.com/security-release-laravel-61834-7232
Restart Required: No
Instructions:
1. Update Laravel via Composer: 'composer update laravel/framework'. 2. Verify version with 'php artisan --version'. 3. Test application functionality after update.
🔧 Temporary Workarounds
Implement explicit validation
allAdd explicit validation rules for all mass-assigned fields to prevent unvalidated data from being saved
Disable mass assignment
allRemove mass assignment from vulnerable models by using $guarded property or explicit fillable arrays
🧯 If You Can't Patch
- Implement strict input validation for all user-controlled data before database operations
- Add application-level authorization checks to verify users have permission to modify specific database tables
🔍 How to Verify
Check if Vulnerable:
Check Laravel version in composer.json or run 'php artisan --version'. If version is <6.18.34 or 7.x <7.23.2, application is vulnerable if using mass assignment.Check Version:
php artisan --versionVerify Fix Applied:
After updating, verify version is >=6.18.34 or >=7.23.2. Test mass assignment functionality with edge cases.📡 Detection & Monitoring
Log Indicators:
- Unusual database queries with unexpected table names
- Mass assignment operations with suspicious parameters
- Errors related to database column mismatches
Network Indicators:
- HTTP requests with unexpected parameter names matching database table structures
SIEM Query:
web_requests WHERE parameters CONTAINS database_table_names AND response_code = 200