Schedule Post Changes With PublishPress Future WordPress Plugin Stored Cross-Site Scripting Vulnerability

A stored cross-site scripting vulnerability has been identified in the Schedule Post Changes With PublishPress Future plugin for WordPress, affecting all versions through 4.10.0. The issue arises from inadequate input sanitization of the 'wrapper' attribute in the '[futureaction]' shortcode. Although the plugin attempts to escape the value using 'esc_html()', this method only encodes HTML entities and fails to prevent attribute injection when the value is formatted as an HTML tag name. This vulnerability allows authenticated attackers with administrator-level access to inject arbitrary scripts into pages, which are executed when users access the injected content. Additionally, administrators can extend this functionality to lower-privileged users, potentially leading to further exploitation.

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 administrator privileges can use the '[futureaction]' shortcode and include a 'wrapper' attribute that injects event handler attributes through spaces. The lack of proper sanitization allows the injected script to be executed when the page is accessed.

Remediation

Users are advised to update the Schedule Post Changes With PublishPress Future plugin to version 4.10.1 or later.