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Cookie Poisoning Via Query/Body Parameters

Cookie Poisoning

What is it?

Cookie Poisoning is a vulnerability caused when client provided parameters (query, and body parameters) are used by the API server to set cookie values.

For example, Bob is using an online shopping website, but is unable to afford the final checkout price of $100. Upon viewing all the cookies contained within his browser, Bob realizes that there is a cookie with a key named checkout_price which was being sent to the server for each transaction that was made.

He notices that the value of the checkout_price cookie is being set by a URL query parameter named transaction_total, in the POST /transact?transaction_total={dollar_amount} API call.

Bob decides to manipulate the checkout_price cookie, by calling the API with POST /transact?transaction_total=-100. This results in his final checkout price of $0.00/.


Test case FAQs

When is this test case applicable?

This is applicable for all API endpoints that allow cookie names/values to be controlled by user input, and when the Baseline security category is enabled in test plans.

How does it work?

User input provided for HTTP query/body parameters are compared to the Set-Coookie values returned by the API endpoint. A potential vulnerability is raised, if either the cookie name or value matches the user supplied input,

What is the solution?

Do not allow user input to control cookie names and values.