The StoreGrowth WordPress plugin before 2.1.2 does not validate a browser-supplied product price on two of its unauthenticated actions, allowing unauthenticated attackers to add a product to the cart at an arbitrary, attacker-chosen price that carries through to the checkout total when the BOGO offer feature is enabled.
https://wpscan.com/vulnerability/15d1a53b-c5f3-4509-9889-ddc48507df35/