Copypress Rest API 1.1 - 1.2 - Missing Configurable JWT Secret and File-Type Validation to Unauthenticated Remote Code Execution

The Copypress Rest API plugin for WordPress is vulnerable to Remote Code Execution via copyreap_handle_image() Function in versions 1.1 to 1.2. The plugin falls back to a hard-coded JWT signing key when no secret is defined and does not restrict which file types can be fetched and saved as attachments. As a result, unauthenticated attackers can forge a valid token to gain elevated privileges and upload an arbitrary file (e.g. a PHP script) through the image handler, leading to remote code execution.