FV Flowplayer Video Player <= 7.5.55.7212 - Unauthenticated Stored Cross-Site Scripting via 'align' Shortcode Attribute

The FV Flowplayer Video Player plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'comment (shortcode attribute 'align')' parameter in all versions up to, and including, 7.5.55.7212 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This requires the plugin's 'Parse Vimeo and YouTube links' (parse_comments) setting to be enabled by an administrator, which causes the plugin to register do_shortcode on the comment_text filter, allowing attacker-supplied shortcode attributes stored in comments to be rendered unescaped to all subsequent visitors.