The User Profile Builder – Beautiful User Registration Forms, User Profiles & User Role Editor…

Why it is Yellow

• CVSS 8.1 high
• Remotely exploitable without logging in

References

• https://plugins.trac.wordpress.org/browser/profile-builder/tags/4.0.3/admin/admin-functions.php#L400
• https://plugins.trac.wordpress.org/browser/profile-builder/tags/4.0.3/features/email-confirmation/email-confirmation.php#L262
• https://plugins.trac.wordpress.org/browser/profile-builder/tags/4.0.3/front-end/class-formbuilder.php#L736
• https://plugins.trac.wordpress.org/browser/profile-builder/tags/4.0.3/front-end/class-formbuilder.php#L793
• https://plugins.trac.wordpress.org/browser/profile-builder/tags/4.0.3/front-end/register.php#L91
• https://plugins.trac.wordpress.org/changeset/3741133/profile-builder
• https://plugins.trac.wordpress.org/changeset/3741133/profile-builder/trunk/features/email-confirmation/email-confirmation.php
• https://www.wordfence.com/threat-intel/vulnerabilities/id/88bfd754-e2ee-47c7-9af5-f31cbe993102?source=cve

Original description

The User Profile Builder – Beautiful User Registration Forms, User Profiles & User Role Editor plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 4.0.3 via the `role` parameter handled by the `wppb_add_meta_to_user_on_activation()` function. The vulnerability exists because the activation handler passes the attacker-supplied role value directly to `WP_User::set_role()` with no allow-list validation, and the 4.0.3 reserved-name check exempts pre-existing form fields from the block, allowing a legacy field with meta-name `role` to persist and bridge attacker-controlled request input into the serialized signup record stored in `wp_signups`. This makes it possible for unauthenticated attackers to gain a fully activated WordPress administrator account by submitting `role=administrator` through the public `[wppb-register]` shortcode form and subsequently clicking the confirmation activation link. Exploitation requires the site to have a legacy form field with meta-name `role` carried over from before the 4.0.3 upgrade, email confirmation enabled, and open user registration — all stable site-state conditions once established.