Items bought for free due to lacks of quantity controls

Hi, The server fails to check the quantity of the items that are going to be sell. Values <= 0 are accepted as 1. PoC: Go here https://sandbox.reverb.com/fr/item/139897-fender-2-strap-leather-test-2018-leather Intercept the response after clicking "Add to cart" and put "quantity: 0" {F302179} Proceed to checkout {F302180} Place order {F302181} {F302182} I used one of the fake credit cards you provide us. ## Impact Items are sold gratis