CVE-2025-27515
📋 TL;DR
A validation bypass vulnerability in Laravel's wildcard file validation allows attackers to upload malicious files by crafting specific request patterns. This affects Laravel applications using wildcard validation (files.*) for file uploads. All applications using vulnerable Laravel versions with file upload functionality are potentially affected.
💻 Affected Systems
- Laravel Framework
📦 What is this software?
Framework by Laravel
Framework by Laravel
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution via malicious file upload leading to complete system compromise, data theft, or ransomware deployment.
Likely Case
Malicious file upload leading to server-side request forgery, local file inclusion, or denial of service attacks.
If Mitigated
Limited impact if additional file type/size validation, proper file storage isolation, and web server security controls are implemented.
🎯 Exploit Status
Exploitation requires file upload functionality with wildcard validation. No public exploit code available at advisory publication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Laravel 11.44.1 or Laravel 12.1.1
Vendor Advisory: https://github.com/laravel/framework/security/advisories/GHSA-78fx-h6xr-vch4
Restart Required: No
Instructions:
1. Update Laravel via composer: 'composer require laravel/framework:^11.44.1' or 'composer require laravel/framework:^12.1.1'. 2. Run 'composer update'. 3. Clear cache: 'php artisan config:clear' and 'php artisan cache:clear'.
🔧 Temporary Workarounds
Manual validation without wildcards
allReplace wildcard validation with explicit field validation for each file upload field
Additional server-side file validation
allImplement server-side file type checking and size validation after Laravel validation
🧯 If You Can't Patch
- Implement strict web server file upload restrictions (size, type, location)
- Use WAF rules to block suspicious file upload patterns and validate file signatures
🔍 How to Verify
Check if Vulnerable:
Check Laravel version in composer.json or run 'php artisan --version'. Verify if using wildcard file validation patterns.Check Version:
php artisan --versionVerify Fix Applied:
Confirm Laravel version is 11.44.1+ or 12.1.1+ via 'php artisan --version'. Test file upload validation with crafted requests.📡 Detection & Monitoring
Log Indicators:
- Unusual file upload patterns with array notation
- Failed validation attempts with crafted field names
- Unexpected file types in upload directories
Network Indicators:
- HTTP POST requests with crafted file field names containing wildcard bypass patterns
SIEM Query:
source="web_logs" AND (method="POST" AND uri="*/upload" AND (form_data LIKE "%files[%" OR form_data LIKE "%files.*%"))