PayPal Pay Now, Buy Now, Donation and Cart Buttons Shortcode <= 1.7 - Contributor+ Stored XSS

The PayPal Pay Now, Buy Now, Donation and Cart Buttons Shortcode WordPress plugin through 1.7 does not validate and escape some of its shortcode attributes before outputting them back in a page/post where the shortcode is embed, which could allow users with the contributor role and above to perform Stored Cross-Site Scripting attacks