Members < 3.2.23 - Unauthenticated Sensitive Information Disclosure via REST API Pagination Side Channel

Description

The Members – Membership & User Role Editor Plugin plugin for WordPress is vulnerable to Sensitive Information Exposure in all versions up to, and including, 3.2.22 via the members_filter_protected_posts_for_rest. This makes it possible for unauthenticated attackers to extract determine the existence and exact count of access-restricted posts, and use per-page pagination as a boolean oracle to infer keywords and content contained within those hidden restricted posts.