SureCart <= 4.9.4 - Unauthenticated Stored Cross-Site Scripting via 'manual-payment-instructions' Attribute of sc-order-manual-instructions in Comments

The SureCart – Ecommerce Made Easy For Selling Physical Products, Digital Downloads, Subscriptions, Donations, & Payments plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'comment' parameter in all versions up to, and including, 4.9.4 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. Successful execution requires the injected comment to be visible on a page that loads SureCart's web-component bundle (e.g. a page containing a SureCart Buy Button block), and the comment must be auto-approved or approved by a moderator.