WordPress Meta Box AIO Plugin Privilege Escalation Vulnerability

The Meta Box AIO plugin for WordPress is vulnerable to privilege escalation to Administrator in versions up to and including 3.11.0.

The flaw is chained. The populate_via_query_string() function in the mb-frontend-submission component unconditionally overrides the form's target object_id from the GET parameter 'rwmb_frontend_field_object_id' without any authorization check, and Form::process() lacks the user_can_edit() check present in render(). This allows unauthenticated attackers to overwrite the post_content of any page with an arbitrary shortcode via wp_update_post().

The mb-user-profile component then directly trusts the 'role' and 'auto_login' shortcode attributes in the injected [mb_user_profile_register] shortcode with no role validation, making it possible for unauthenticated attackers to elevate their privileges to Administrator.

Affected versions:

• Meta Box AIO: up to and including 3.11.0
• Meta Box Frontend Submission: up to 4.5.6
• Meta Box User Profile: up to 3.11.0