LoginPress Pro <= 6.2.3 - Unauthenticated Authentication Bypass via Unverified OAuth Email in Spotify OAuth Callback

The LoginPress Pro plugin for WordPress is vulnerable to authentication bypass in versions up to and including 6.2.3 via the Spotify Social Login addon. This is due to the loginpress_on_spotify_login() function trusting the unverified 'email' field returned by Spotify's /v1/me endpoint and using it directly with get_user_by('email', $profile['email']) to identify and log in an existing WordPress account, without confirming that the Spotify user actually owns the email address (Spotify documents that the profile email is unverified) and without requiring the user to prove ownership of the matching WordPress account. This makes it possible for unauthenticated attackers to log in as any existing WordPress user, including Administrators, by registering a Spotify account using the targeted user's email address and authenticating via the Spotify provider.