KIA Subtitle WordPress Plugin Stored Cross-Site Scripting Vulnerability

A stored cross-site scripting vulnerability has been identified in the KIA Subtitle plugin for WordPress, affecting all versions through 4.0.1. The issue arises from inadequate input sanitization and output escaping for user-supplied attributes in the plugin's 'the-subtitle' shortcode, specifically the 'before' and 'after' attributes. This vulnerability allows authenticated attackers with Contributor-level access or higher to inject arbitrary web scripts into pages, which are executed when users access the injected 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 Contributor-level access or higher can use the 'the-subtitle' shortcode and include a script in the 'before' or 'after' attributes. Once the subtitle is saved, the injected script will execute when the page is viewed.

Remediation

Users are advised to update the KIA Subtitle plugin to version 4.0.2 or a newer patched version.