backpack/crud provides Create, Read, Update & Delete (CRUD) functions for Backpack, a collection of Laravel packages that help users build custom administration panels. From 6.0.0 until 6.8.14 and 7.0.38, HasUploadFields methods uploadFileToDisk and uploadMultipleFilesToDisk, used through CrudTrait, and the withFiles() path through FileNameGenerator do not internally reject server-executable file types. An authenticated administrator can achieve remote code execution by using an upload-enabled CRUD field without mimes: and mimetypes: validation when the public disk is web-accessible through php artisan storage:link and the web-server and PHP-FPM configuration executes the stored extension. The legacy path preserves an accepted extension and the newer path derives an extension without blocking dangerous types. The package-level restriction is defense in depth and does not replace application-level upload validation. This issue is fixed in versions 6.8.14 and 7.0.38.

Affected: Packagist: backpack/crud

## Summary

`HasUploadFields` (used via `CrudTrait` on Backpack-managed models) and the `withFiles()` uploader preserve the client-supplied file extension without validation. On installations using a `public` disk with `php artisan storage:link`, this allows an authenticated administrator to upload a file with a server-executable extension that the web server will pass to the PHP interpreter - if no MIME or other type of upload validation is present.

## Details

The `uploadFileToDisk` and `uploadMultipleFilesToDisk` methods hash the filename stem but write the client-supplied extension to disk verbatim — no allowlist, blocklist, or MIME check is applied inside the trait itself.

The newer `withFiles()` path (via `FileNameGenerator`) resolves the extension from the file's MIME type rather than the client filename, but also does not block server-executable types.

Applications that follow the Backpack quickstart without adding explicit `mimes:` or `mimetypes:` validation rules in their form requests are affected.

## Impact

An authenticated administrator with access to an upload-enabled CRUD panel, on a site using the `public` disk with web-accessible storage and no MIME type validation, can upload a server-executable file and achieve remote code execution.

**Conditions required for exploitation:**

- Authenticated admin access to a Backpack CRUD panel - An upload field with no `mimes:` / `mimetypes:` validation rule - The `public` disk in use (standard pattern for web-visi…