Blubrry PowerPress < 11.15.3 - Authenticated (Contributor+) Arbitrary File Upload via 'powerpress_edit_post'

Description

The Blubrry PowerPress plugin for WordPress is vulnerable to arbitrary file uploads due to insufficient file type validation in all versions up to, and including, 11.15.2. This is due to the plugin validating file extensions but not halting execution when validation fails in the 'powerpress_edit_post' function. This makes it possible for authenticated attackers, with Contributor-level access and above, to upload arbitrary files on the affected site's server which may make remote code execution possible.