Critical advisory for The Ultra Addons for Contact Form 7 plug

Advisory overview

The Ultra Addons for Contact Form 7 plugin for WordPress is vulnerable to arbitrary file deletion due to insufficient file path validation in the _getObjAttr function in all versions up to, and including, 3.5.54. 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). This requires the PDF Generator add-on to be active and a Contact Form 7 form to be configured for PDF generation, as the WPCF7_Submission POP gadget chain relies on CF7 being present to complete the file deletion via __destruct(). Note: This vulnerability can only be exploited when the PDF generator feature is enabled.

Related references

• https://plugins.svn.wordpress.org/ultimate-addons-for-contact-form-7/tags/3.5.52/addons/pdf-generator/pdf-generator.php
• https://plugins.trac.wordpress.org/changeset/3738548/ultimate-addons-for-contact-form-7
• https://www.wordfence.com/threat-intel/vulnerabilities/id/187777a4-3438-489c-ad3b-7e16753189d6?source=cve