OneSignal – Web Push Notifications <= 3.8.0 - Missing Authorization to Authenticated (Subscriber+) Post Meta Deletion via 'post_id'

The OneSignal – Web Push Notifications plugin for WordPress is vulnerable to authorization bypass in versions up to, and including, 3.8.0. This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for authenticated attackers, with subscriber-level access and above, to delete OneSignal metadata for arbitrary posts.