WooCommerce Pre-Orders < 2.0.1 - Contributor+ Stored XSS

The plugin does not validate and escape its layout shortcode attribute before outputting it 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

PoC

[woocommerce_pre_order_countdown product_id=“64” layout=“‘-alert(/XSS/)-’”] 64 being a product set as a pre-order with an availability date in the future