Excessive trust in client-side controls

We can click on the My account button and login using the following credentials:

Username	Password
wiener	peter

We can now go back to the web store and click on the "Lightweight l33t leather jacket".

Let's add the product to the cart.

We can place the order but it won't go through because we don't have enough credits.

Since we are proxying the traffic Burp Suite, we can view this request through the Proxy > HTTP History tab.

Let's forward the request to the Repeater for further modifications. Once in the Repeater, we can set the price parameter to the following:

9

Let's send the request.

If we check our cart through the browser, we can see that the price of the product has been set to the modified price parameter's value. The quantity has also been updated.

Since the total price is less than our credits, we can now place the order.

We have solved the lab.