Livewire is a full-stack framework for Laravel that allows for dynamic UI components without leaving PHP. In livewire/livewire prior to 2.12.7 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: 1. Filename is composed of the original file name using $file->getClientOriginalName(). 2. Files stored directly on your server in a public storage disk. 3. Webserver is configured to execute “.php” files. This issue has been addressed in release versions 2.12.7 and 3.5.2. All…