High advisory for The Contact Form Extender for Divi Build

Advisory overview

The Contact Form Extender for Divi Builder plugin for WordPress is vulnerable to Arbitrary File Deletion due to insufficient file path validation in the cfefd_remove_uploaded_file() function in all versions up to, and including, 1.0.6. This makes it possible for unauthenticated attackers to delete arbitrary files on the server, which can easily lead to remote code execution when the right file is deleted (such as wp-config.php). The nonce protecting this AJAX action is rendered into the public page source via wp_localize_script and is therefore retrievable by any unauthenticated visitor.

Related references

• https://plugins.trac.wordpress.org/browser/contact-form-extender-for-divi-builder/tags/1.0.3/includes/module/addons/divi-4/file-upload/class-cfefd-file-upload-ajax.php#L159
• https://plugins.trac.wordpress.org/browser/contact-form-extender-for-divi-builder/tags/1.0.3/includes/module/addons/divi-4/file-upload/class-cfefd-file-upload-ajax.php#L18
• https://plugins.trac.wordpress.org/browser/contact-form-extender-for-divi-builder/tags/1.0.7/includes/module/addons/divi-4/file-upload/class-cfefd-file-upload-ajax.php#L166
• https://plugins.trac.wordpress.org/changeset?old_path=contact-form-extender-for-divi-builder%2Ftags%2F1.0.6&new_path=contact-form-extender-for-divi-builder%2Ftags%2F1.0.7
• https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&new=3499767%40contact-form-extender-for-divi-builder%2Ftrunk&old=3499766%40contact-form-extender-for-divi-builder%2Ftrunk&sfp_email=&sfph_mail=
• https://wordpress.org/plugins/contact-form-extender-for-divi-builder/#developers
• https://www.wordfence.com/threat-intel/vulnerabilities/id/7bbead7c-47b9-473f-b335-6fae4b5998d6?source=cve