Media.net Ads Manager <= 2.10.13 - Missing Authorization to Authenticated (Subscriber+) Arbitrary File Upload

The Media.net Ads Manager plugin for WordPress is vulnerable to arbitrary file uploads due to missing file type validation and missing capability check in the 'sendMail' function in all versions up to, and including, 2.10.13. This makes it possible for authenticated attackers, with subscriber-level and above permissions, to upload arbitrary files on the affected site's server which may make remote code execution possible. The vulnerability is only exploitable if anyone has ever logged in through the API.