Auto Featured Image <= 1.2 - Authenticated (Contributor+) Arbitrary File Upload

The Auto Featured Image plugin for WordPress is vulnerable to arbitrary file uploads due to missing file type validation in the 'create_post_attachment_from_url' function in all versions up to, and including, 1.2. This makes it possible for authenticated attackers, with contributor-level and above permissions, to upload arbitrary files on the affected site's server which may make remote code execution possible.