LearnPress <= 4.4.10 - Missing Authorization to Authenticated (Subscriber+) Email Address Enumeration via 'search-authors' AJAX Action

The LearnPress – WordPress LMS Plugin for Create and Sell Online Courses plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 4.4.10 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 enumerate the complete site user roster and extract the full email address of any WordPress account, including administrator accounts, character-by-character by using the search response as an oracle against both user_login and user_email columns.