CVE-2026-9242
Vulnérabilité moyenne dans RegistrationMagic – Custom Registration Forms, User Registration, Payment, and User Login (metagauss)
Description
The RegistrationMagic – Custom Registration Forms, User Registration, Payment, and User Login plugin for WordPress is vulnerable to Authentication Bypass via Insufficient Verification of Data Authenticity in all versions up to and including 6.0.8.6. This is due to the PayPal IPN `callback` handler being registered as a nopriv AJAX action with no authentication or nonce requirement, and critically because the handler updates the payment log database row with attacker-controlled POST data — including `payment_status` and the `custom` field encoding the target `user_id` — before PayPal IPN validation is performed, meaning the database remains poisoned even when validation subsequently fails. This makes it possible for unauthenticated attackers to authenticate as any WordPress user, including administrators, by submitting a forged IPN request that overwrites a payment log entry's `user_id` with that of a target account, then visiting the success return URL with a legitimately obtained security hash to cause the plugin to issue real WordPress authentication cookies for the targeted account.
Gravité et risque d'exploitation
CVE-2026-9242 obtient un score CVSS de 5.3/10, soit une gravité moyenne. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.34 %, ce qui la place devant 25.7 % des CVE référencées.
Que faire ?
- Vérifiez si RegistrationMagic – Custom Registration Forms, User Registration, Payment, and User Login (versions 0, <=6.0.8.6) est présent sur votre parc.
- Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
- À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
- Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.
Références
- https://www.wordfence.com/threat-intel/vulnerabilities/id/1dcf68fd-e9d3-4a46-8bd4-15c2598b91fe?source=cve
- https://plugins.trac.wordpress.org/browser/custom-registration-form-builder-with-submission-manager/trunk/services/class_rm_paypal_service.php#L155
- https://plugins.trac.wordpress.org/browser/custom-registration-form-builder-with-submission-manager/tags/6.0.8.4/services/class_rm_paypal_service.php#L155
- https://plugins.trac.wordpress.org/browser/custom-registration-form-builder-with-submission-manager/trunk/public/class_rm_public.php#L728
- https://plugins.trac.wordpress.org/browser/custom-registration-form-builder-with-submission-manager/tags/6.0.8.4/public/class_rm_public.php#L728
- https://plugins.trac.wordpress.org/browser/custom-registration-form-builder-with-submission-manager/trunk/services/class_rm_paypal_service.php#L110
- https://plugins.trac.wordpress.org/browser/custom-registration-form-builder-with-submission-manager/tags/6.0.8.4/services/class_rm_paypal_service.php#L110
- https://plugins.trac.wordpress.org/browser/custom-registration-form-builder-with-submission-manager/trunk/includes/class_rm_utilities.php#L1384
- https://plugins.trac.wordpress.org/browser/custom-registration-form-builder-with-submission-manager/tags/6.0.8.4/includes/class_rm_utilities.php#L1384
- https://plugins.trac.wordpress.org/browser/custom-registration-form-builder-with-submission-manager/tags/6.0.8.1/services/class_rm_paypal_service.php#L155
- https://plugins.trac.wordpress.org/browser/custom-registration-form-builder-with-submission-manager/tags/6.0.8.1/public/class_rm_public.php#L728
- https://plugins.trac.wordpress.org/browser/custom-registration-form-builder-with-submission-manager/tags/6.0.8.1/services/class_rm_paypal_service.php#L110
- https://plugins.trac.wordpress.org/browser/custom-registration-form-builder-with-submission-manager/tags/6.0.8.1/includes/class_rm_utilities.php#L1384
- https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3532900%40custom-registration-form-builder-with-submission-manager&new=3532900%40custom-registration-form-builder-with-submission-manager&sfp_email=&sfph_mail=