Zero-Day Advisory

Fortinet Discovers WordPress Visual Composer Website Builder Plugin Cross-Site Scripting Vulnerability

Summary

Fortinet's FortiGuard Labs has discovered a cross-site scripting (XSS) vulnerability in WordPress Visual Composer Website Builder Plugin.


WordPress Visual Composer is a popular, free, fast, SEO-friendly website and landing page builder plugin. It's a most feature-rich free page builder - 50+ free elements, 10+ free landing page templates, and advanced design options with background and parallax effects.


The Visual Composer Website Builder plugin is vulnerable to Stored Cross-Site Scripting via the 'Title' value due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers with access to the visual composer editor to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Solutions

FortiGuard Labs released the following FortiGate IPS signature which covers this specific vulnerability:

WordPress.Plugin.Visual.Composer.Website.Builder.TextEditor.XSS
Released Aug 30, 2022

Users should apply the solution provided by Visual Composer Team.


Timeline

Fortinet reported the vulnerability to Visual Composer Team on December 22, 2021

Visual Composer Team patched the vulnerability on January 4, 2022

Acknowledgement

This vulnerability was discovered by Vishnupriya Ilango & Zhouyuan Yang of Fortinet's FortiGuard Labs.

IPS Subscription

Fortinet customers who subscribe to Fortinet's intrusion prevention (IPS) service should be protected against this vulnerability with the appropriate configuration parameters in place. Fortinet's IPS service is one component of FortiGuard Subscription Services, which also offer comprehensive solutions such as antivirus, Web content filtering and antispam capabilities. These services enable protection against threats on both application and network layers. FortiGuard Services are continuously updated by FortiGuard Labs, which enables Fortinet to deliver a combination of multi-layered security intelligence and true zero-day protection from new and emerging threats. These updates are delivered to all FortiGate, FortiMail and FortiClient products. Fortinet strictly follows responsible disclosure guidelines to ensure optimum protection during a threat's lifecycle.