CVE-2025-27515: Laravel Framework Auth Bypass Vulnerability

CVE-2025-27515 Overview

Laravel is a web application framework. When using wildcard validation to validate a given file or image field (files.*), a user-crafted malicious request could potentially bypass the validation rules. This vulnerability is fixed in versions 11.44.1 and 12.1.1.

Critical Impact
Medium severity vulnerability allowing invalid file uploads via malformed requests.

Affected Products

Laravel Framework

Discovery Timeline

Not Available - Vulnerability discovered by Not Available
Not Available - Responsible disclosure to laravel
Not Available - CVE CVE-2025-27515 assigned
Not Available - laravel releases security patch
2025-03-05 - CVE CVE-2025-27515 published to NVD
2025-08-26 - Last updated in NVD database

Technical Details for CVE-2025-27515

Vulnerability Analysis

The vulnerability arises from improper validation of file uploads when using wildcard validation (files.*) in Laravel. An attacker can exploit this by crafting a request that bypasses intended validation rules.

Root Cause

Improper input validation in the file upload process when using wildcard rules.

Attack Vector

Network

php

// Example exploitation code (sanitized)
$client = new \GuzzleHttp\Client();
$response = $client->post('http://vulnerable-site/upload', [
    'multipart' => [
        [
            'name' => 'files[0]',
            'contents' => fopen('/path/to/malicious/file', 'r')
        ]
    ]
]);

Detection Methods for CVE-2025-27515

Indicators of Compromise

Unexpected file uploads
Unusual HTTP POST requests
Logs indicating bypassed validations

Detection Strategies

Monitor for unexpected file types being uploaded or bypassing set rules. Analyze logs for irregularities in validation signatures.

Monitoring Recommendations

Implement logging for all file uploads and validate logs for anomalies. Use IDS/IPS to detect suspicious file upload patterns.

How to Mitigate CVE-2025-27515

Immediate Actions Required

Upgrade to Laravel version 11.44.1 or 12.1.1
Implement additional server-side validation
Conduct a thorough code review of upload processes

Patch Information

Patches have been provided by Laravel in versions 11.44.1 and 12.1.1. More information can be found in the official patch.

Workarounds

Enforce strict server-side validation and sanitization rules for file uploads to prevent bypass attempts.

bash

# Configuration example
# Adjust nginx to limit upload size and types
location /upload {
    limit_except POST { deny all; }
    client_max_body_size 10M;
    # Allow only image file types
    if ($content_type !~ ^image/) {
        return 403;
    }
}