Prevent File Inclusion Vulnerabilities in Laravel

Laravel, one of the most popular PHP frameworks, empowers developers to create robust applications. However, like any framework, improper implementation can introduce vulnerabilities such as File Inclusion Attacks, potentially exposing sensitive data or executing malicious scripts.

In this guide, we’ll explore how file inclusion vulnerabilities work in Laravel, how to prevent them, and provide actionable coding examples to keep your application secure.

What Are File Inclusion Vulnerabilities?

File inclusion vulnerabilities occur when attackers manipulate file paths to include unauthorized files on the server. There are two primary types:

1. Local File Inclusion (LFI): Attackers exploit vulnerabilities to access files on the local server.
2. Remote File Inclusion (RFI): Attackers use vulnerabilities to include malicious files from a remote server.

These vulnerabilities often result from improper handling of user inputs, making it critical to validate and sanitize inputs thoroughly.

How File Inclusion Happens in Laravel

Consider a poorly implemented Laravel route:

Route::get('/include-file', function (Request $request) {
    $file = $request->input('file'); // Unvalidated user input
    include($file); // Potentially dangerous
});

In this example, the $file parameter is directly included, allowing attackers to inject malicious file paths.

Preventing File Inclusion in Laravel

1. Validate Input

Use Laravel’s built-in validation to restrict acceptable file paths.

Route::get('/include-file', function (Request $request) {
    $validated = $request->validate([
        'file' => 'required|string|in:allowed_file.php,another_file.php',
    ]);

    include($validated['file']);
});

2. Use Absolute Paths

Restrict file inclusion to specific directories:

Route::get('/include-file', function (Request $request) {
    $file = basename($request->input('file'));
    $path = storage_path('safe_files/' . $file);

    if (file_exists($path)) {
        include($path);
    } else {
        abort(404, 'File not found');
    }
});

3. Disable Dangerous PHP Functions

Disabling functions like include, require, and eval at the server level reduces risk.

4. Leverage Security Tools

Using tools to regularly assess your application’s vulnerabilities is essential.

Identify Vulnerabilities with Our Free Security Tool

To ensure your Laravel application is free from file inclusion vulnerabilities, use our Free Website Security Checker.

Screenshot of the free tools webpage where you can access security assessment tools.

Upload your URL, and within seconds, you’ll receive a detailed vulnerability assessment report:

Example Vulnerability Assessment

Using our free tool, developers found and fixed a critical LFI vulnerability where unauthorized access to /.env exposed sensitive environment variables.

Before Fix:

Route::get('/file', function (Request $request) {
    $file = $request->input('file');
    include($file);
});

After Fix:

Route::get('/file', function (Request $request) {
    $validated = $request->validate([
        'file' => 'required|string|in:safe_file.php',
    ]);

    include(storage_path('safe_files/' . $validated['file']));
});

Example of a vulnerability assessment report generated with our free tool, providing insights into possible vulnerabilities.

Conclusion

Protecting your Laravel application from file inclusion vulnerabilities is critical. By validating inputs, using secure coding practices, and leveraging tools like our Free Website Security Scanner, you can safeguard your application and its users.

Take the first step toward enhanced security — Leverage tools like ours to test website security free.