The Divi Membership plugin for WordPress is vulnerable to Privilege Escalation in versions up to, and including, 2.2.0

Overview

The Divi Membership plugin for WordPress is vulnerable to Privilege Escalation in versions up to, and including, 2.2.0. This is due to the dmem_form_submit_handler() function determining the new user's role by iterating all WordPress roles and calling password_verify() against an attacker-controlled bcrypt hash supplied in the form_id POST parameter, with no validation or whitelist of allowed roles. This makes it possible for unauthenticated attackers to register a new account with the administrator role by submitting a locally computed bcrypt hash of administrator as form_id, and when auto_login=on is submitted, be immediately authenticated as that administrator in the same request, resulting in full site takeover. Exploitation requires a WordPress nonce, but that nonce is publicly emitted on any page rendering the Divi Membership registration form and is therefore obtainable by any unauthenticated visitor.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.