CRM Memberships <= 2.6 - Missing Authorization to Privilege Escalation via Unauthenticated Password Reset in 'ntzcrm_changepassword' AJAX Endpoint

The CRM Memberships plugin for WordPress is vulnerable to privilege escalation via password reset in all versions up to, and including, 2.6. This is due to missing authorization and authentication checks on the `ntzcrm_changepassword` AJAX action. This makes it possible for unauthenticated attackers to reset arbitrary user passwords and gain unauthorized access to user accounts via the `ntzcrm_changepassword` endpoint, granted they can obtain or enumerate a target user's email address. The plugin also exposes the `ntzcrm_get_users` endpoint without authentication, allowing attackers to enumerate subscriber email addresses, facilitating the exploitation of the password reset vulnerability.