Newsletter - API v1 and v2 addon for Newsletter < 2.4.6 - Missing Authorization to Email Subscribers Management

Description

The Newsletter - API v1 and v2 addon plugin for WordPress is vulnerable to unauthorized subscribers management due to PHP type juggling issue on the check_api_key function in all versions up to, and including, 2.4.5. This makes it possible for unauthenticated attackers to list, create or delete newsletter subscribers. This issue affects only sites running the PHP version below 8.0