The Gravity Forms plugin for WordPress is vulnerable to arbitrary file uploads due to missing file type validation in the copypostimage() function in all versions up to, and including, 2.9.20. This makes it possible for unauthenticated attackers to upload arbitrary files on the affected site's server which may make remote code execution possible. This only impacts sites that have allowurlfopen set to On, the post creation form enabled along with a file upload field for the post