Crypto <= 2.19 - Authentication Bypass via register

The Crypto plugin for WordPress is vulnerable to authentication bypass in versions up to, and including, 2.19. This is due to missing validation on the user being supplied in the 'crypto_connect_ajax_process::register' function. This makes it possible for unauthenticated attackers to log in as any existing user on the site, such as an administrator, if they have access to the username.