The NewsmanApp plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'billing_first_name, billing_last_name' parameter in all versions up to, and including, 3.7.29 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 vulnerability is only exploitable when the Newsman Remarketing feature is enabled and a non-empty Remarketing ID is configured in the plugin settings.