Simple Football Scoreboard <= 1.0 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Attributes

The Simple Football Scoreboard plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'ytmr_fb_scoreboard' shortcode in all versions up to, and including, 1.0 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.