GHSA-f3cx-396f-7jqp Livewire Remote Code Execution on File Uploads

• Packagist livewire/livewire: >= 3.0.0-beta.1, < 3.5.2 → fixed in 3.5.2 • Packagist livewire/livewire: < 2.12.7 → fixed in 2.12.7

In livewire/livewire prior to `v2.12.7` and `v3.5.2`, the file extension of an uploaded file is guessed based on the MIME type. As a result, the actual file extension from the file name is not validated. An attacker can therefore bypass the validation by uploading a file with a valid MIME type (e.g., `image/png`) and a “.php” file extension. If the following criteria are met, the attacker can carry out an RCE attack: • Filename is composed of the original file name using `$file->getClientOriginalName()` • Files stored directly on your server in a public storage disk • Webserver is configured to execute “.php” files PoC In the following scenario, an attacker could upload a file called `shell.php` with an `image/png` MIME type and execute it on the remote server. ```php class SomeComponent extends Component { use WithFileUploads; #[Validate('image|extensions:png')] public $file; public function save() { $this->validate(); $this->file->storeAs( path: 'images', name: $this->file->getClientOriginalName(), options: ['disk' => 'public'], ); } } ```