NEX-Forms WordPress Plugin Stored Cross-Site Scripting Vulnerability

A stored cross-site scripting vulnerability has been identified in the NEX-Forms WordPress plugin, specifically in the 'Ultimate Form Builder - Contact forms and much more' version 8.9.1 and earlier. This vulnerability arises from inadequate input sanitization and output escaping, allowing authenticated attackers with Custom-level access to inject arbitrary scripts into pages. The injected scripts are executed when users access the compromised pages.

Impact

Exploitation of this vulnerability allows for stored cross-site scripting, where injected scripts are executed in the context of the user viewing the page.

Reproduction

To reproduce this vulnerability, an authenticated user with Custom-level access can inject scripts through the 'clean_html' and 'form_fields' parameters. The injected scripts will be executed when the page is accessed by a user.

Remediation

Users are advised to update the NEX-Forms WordPress plugin to version 8.9.2 or a newer patched version.