The Author Bio Box WordPress plugin is vulnerable to Stored Cross-Site Scripting due to insufficient input validation and sanitization via several parameters found in the ~/includes/admin/class-author-bio-box-admin.php file which allowed attackers with administrative user access to inject arbitrary web scripts, in versions up to and including 3.3.1. This affects multi-site installations where unfiltered_html is disabled for administrators, and sites where unfiltered_html is disabled.