CVE-2026-120070 User Frontend <= 4.3.13 - Authenticated (Subscriber+) Privilege Escalation via post_content Parameter

Description

The User Frontend – Membership, User Registration, User Profile, User Directory & Content Restriction with Frontend Post Submission plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 4.3.13 via the `post_content` parameter of the `submit_post()` function. The vulnerability exists because the protected-shortcode blocklist guard inspects the `sanitize_textarea_field()` copy of the submitted `post_content`, while the copy actually persisted to the database is processed through `wp_kses()`, whose `wp_kses_no_null()` step strips C0 control bytes — allowing an attacker to inject a single `\x01` byte inside the `[wpuf-registration]` tag name to defeat the `strpos()` blocklist check while the clean, functional shortcode is stored verbatim; `strip_shortcodes()` does not neutralize the stored shortcode either, because the Frontend container that registers it via `add_shortcode()` is only instantiated when `is_admin()` is false, and `admin-ajax` requests have `is_admin() === true`. This makes it possible for authenticated attackers, with Subscriber-level access and above, to inject a `[wpuf-registration role="editor"]` shortcode into a published post, causing a live Editor-role registration form to be rendered publicly on the frontend that any visitor — or the attacker themselves — can submit to mint a WordPress Editor account with an immediately active privileged session when the default `autologin_after_registration` setting is enabled.

Exploitable à distance par le réseau, avec un compte ordinaire et sans action d’un utilisateur ; un attaquant peut compromettre gravement la confidentialité, l’intégrité ou la disponibilité.

Vecteur d’attaque

Réseau

Complexité

Faible

Privilèges requis

Faibles

Interaction

Aucune

Portée

Inchangée

Confidentialité

Élevé

Intégrité

Élevé

Disponibilité

Élevé

Produits et versions touchés