Simplify Contact Management: WP Easy Contact <= 4.0.0 - Authenticated (Contributor+) Stored Cross-Site Scripting

The Simple Contact Form Plugin for WordPress – WP Easy Contact plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'emd_mb_meta' shortcode in all versions up to, and including, 4.0.0 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.