The WordPress Simple Shopping Cart plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'wpcartbutton' and 'wpcartdisplayproduct' shortcodes in all versions up to, and including, 5.0.7 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The WordPress Simple Shopping Cart plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'wpcartbutton' shortcode in all versions up to, and including, 5.1.3 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The WordPress Simple Shopping Cart plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 5.1.3 due to lack of randomization of a user controlled key. This makes it possible for unauthenticated attackers to access customer shopping carts and edit product links, add or delete products, and discover coupon codes.

The WordPress Simple Shopping Cart plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 5.1.3 via the 'processpaymentdata' due to missing validation on a user controlled key. This makes it possible for unauthenticated attackers to change the quantity of a product to a negative number, which subtracts the product cost from the total order cost. The attack will only work with Manual Checkout mode, as PayPal and Stripe will not process payments for a negative quantity.