Responsive Blocks WordPress Plugin Stored Cross-Site Scripting Vulnerability

A stored cross-site scripting vulnerability has been identified in the Responsive Blocks - WordPress Gutenberg Blocks plugin, affecting all versions through 1.9.9. The issue arises from inadequate input sanitization and output escaping, allowing authenticated attackers with Contributor-level access or higher to inject arbitrary scripts into pages. These scripts are executed when a user accesses the affected page.

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 Contributor-level access or higher can inject scripts via the 'section_tag' parameter. This can be done by creating or editing a post and using a block that accepts the 'section_tag' parameter, such as the Post Carousel block. The injected script will be executed when the post is viewed.

Remediation

Users are advised to update the Responsive Blocks - WordPress Gutenberg Blocks plugin to version 2.0.0 or later.