EG-Series WordPress Plugin Stored Cross-Site Scripting Vulnerability

A stored cross-site scripting vulnerability has been identified in the EG-Series plugin for WordPress, affecting all versions through 2.1.1. The issue arises from inadequate input sanitization and output escaping of user-supplied attributes in the shortcode_title function. This vulnerability allows authenticated attackers with contributor-level access or higher, on sites using the Classic Editor plugin, to inject arbitrary JavaScript into the titletag attribute. The injected script executes when a user accesses the page containing the shortcode.

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.