Ultimate Member < 2.9.0 - Missing Authorization to Authenticated (Subscriber+) Arbitrary User Profile Picture Update

Description

The Ultimate Member – User Profile, Registration, Login, Member Directory, Content Restriction & Membership Plugin plugin for WordPress is vulnerable to unauthorized profile picture updates due to a missing capability check on the wp_ajax_um_resize_image() and ajax_resize_image() functions in all versions up to, and including, 2.8.9. This makes it possible for authenticated attackers, with subscriber-level access and above, to update the profile pictures of other users.