WP Mail Catcher <= 2.1.2 - Unauthenticated Stored Cross-Site Scripting via Email Subject

The WP Mail Catcher plugin for WordPress is vulnerable to Stored Cross-Site Scripting via an email subject in versions up to, and including, 2.1.2 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.