404 to 301 <= 2.3.0 - Unauthenticated Stored Cross-Site Scripting (XSS)

Description

There is a stored XSS in the 404-to-301 WP plugin < 2.3.1. Unauthenticated users can visit a specially crafted URL and the redirect path will be logged to the database. The redirection source is stored unescaped in the database, thus it is served as-is and evaluated in the browsers of logged-in admins when they check the redirection logs on http://wordpress/wp-admin/admin.php?page=i4t3-logs. Affected versions are <2.3.1.