Eventin < 4.0.35 - Authenticated (Contributor+) Privilege Escalation via User Email Change/Account Takeover

Description

The Eventin plugin for WordPress is vulnerable to privilege escalation via account takeover in all versions up to, and including, 4.0.34. This is due to the plugin not properly validating a user's identity or capability prior to updating their details like email in the 'Eventin\Speaker\Api\SpeakerController::update_item' function. This makes it possible for unauthenticated attackers with contributor-level and above permissions to change arbitrary user's email addresses, including administrators, and leverage that to reset the user's password and gain access to their account.