Is Simple Shopping Cart safe? Known vulnerabilities and latest version

The Simple Shopping Cart WordPress plugin before 5.3.3 does not verify submitted product prices against a value only the site owner can set, allowing users with the Contributor role and above to register attacker-chosen prices for existing products, which any visitor can then use to add those products to the cart at that price.

The Simple Shopping Cart WordPress plugin before 5.3.3 does not verify that a PayPal payment notification is for a payment received by the site owner's PayPal account in its default configuration, allowing unauthenticated attackers to have their orders marked as paid using a payment made to an account they control.

The Simple Shopping Cart WordPress plugin before 5.2.6 does not escape some of its settings field values before outputting them on an admin settings page, allowing high-privilege users such as administrators to perform Stored Cross-Site Scripting attacks, which is notably impactful on multisite installations where administrators do not have the unfiltered_html capability.

Unauthenticated Insecure Direct Object References (IDOR) in Simple Shopping Cart <= 5.2.9 versions.

The Simple Shopping Cart plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'wpsc_display_product' shortcode in all versions up to, and including, 5.2.4 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 'process_payment_data' 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.

The WordPress Simple Shopping Cart plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'wp_cart_button' 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 Sensitive Information Exposure in all versions up to, and including, 5.1.2 via the 'file_url' parameter. This makes it possible for unauthenticated attackers to view potentially sensitive information and download a digital product without paying for it.

The WordPress Simple Shopping Cart plugin for WordPress is vulnerable to product price manipulation in all versions up to, and including, 5.1.2. This is due to a logic flaw involving the inconsistent use of parameters during the cart addition process. The plugin uses the parameter 'product_tmp_two' for computing a security hash against price tampering while using 'wspsc_product' to display the product, allowing an unauthenticated attacker to substitute details from a cheaper product and bypass payment for a more expensive item.

The WordPress Simple Shopping Cart plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'wp_cart_button' and 'wp_cart_display_product' 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 automatic redirect URL setting in all versions up to and including 4.7.1 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with administrator-level permissions and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This only affects multi-site installations and installations where unfiltered_html has been disabled.

The WP Simple Shopping Cart plugin for WordPress is vulnerable to Sensitive Information Exposure in versions up to, and including, 4.6.3 due to the plugin saving shopping cart data exports in a publicly accessible location (/wp-content/plugins/wordpress-simple-paypal-shopping-cart/includes/admin/). This makes it possible for unauthenticated attackers to view information that should be limited to administrators only and can include data like first name, last name, email, address, IP Address, and more.