Which attack modifies a cookie’s contents to bypass security mechanisms?

• A. Web Service Attack
• B. Cookie Snooping
• C. Unvalidated Inputs
• D. Cookie poisoning attack

Answer: (D)

Tampering with data stored on the client to influence how the server behaves is the key idea. Cookies are small bits of data that the browser sends with each request, often containing session IDs or tokens that the server uses to identify and authorize the user. When those cookie values are trusted by the server without proper integrity checks, an attacker can alter a cookie’s contents to impersonate another user, gain higher privileges, or bypass authentication and access controls. This manipulation is known as a cookie poisoning attack.

The other options don’t fit this specific scenario. A web service attack targets weaknesses in the service itself, not necessarily the tampering of client-side cookies. Cookie snooping refers to capturing cookies (often to steal session data) rather than modifying them to change server behavior. Unvalidated inputs describe general input validation flaws on the server, not the act of altering a cookie to bypass security mechanisms.