Which attack involves manipulating parameters exchanged between client and server to modify application data such as user credentials, permissions, and product prices?

Which attack involves manipulating parameters exchanged between client and server to modify application data such as user credentials, permissions, and product prices?

• A. Parameter/Form Tampering Attack
• B. Cookie Tampering
• C. Unvalidated Input and File Injection Attacks
• D. Command Injection Attacks

Answer: (A)

The idea being tested is parameter/form tampering, which means changing the data that the client sends to the server in requests (such as form fields, query strings, hidden fields, or API payloads) in order to affect how the application behaves or what data it uses. If the server trusts this client-provided data without rechecking it, an attacker can alter values that govern who can do what, what price should be charged, or what credentials are in effect, leading to privilege escalation, unauthorized access, or financial manipulation. For example, changing a hidden form field that indicates a user’s role or altering a price value sent in a transaction can trick the server into granting higher permissions or charging less than intended. Effective defense requires validating all critical data on the server side, not trusting any data from the client, and using measures like server-side authorization checks, consistent re-computation of prices, and integrity protections (signing or binding critical fields to the user session) to ensure the data hasn’t been tampered with. Other options focus on different vectors: cookie tampering targets only cookies, while unvalidated input and file injection or command injection involve injecting malicious input into processing or system commands rather than altering in-transit parameters to change application state.

The idea being tested is parameter/form tampering, which means changing the data that the client sends to the server in requests (such as form fields, query strings, hidden fields, or API payloads) in order to affect how the application behaves or what data it uses. If the server trusts this client-provided data without rechecking it, an attacker can alter values that govern who can do what, what price should be charged, or what credentials are in effect, leading to privilege escalation, unauthorized access, or financial manipulation. For example, changing a hidden form field that indicates a user’s role or altering a price value sent in a transaction can trick the server into granting higher permissions or charging less than intended. Effective defense requires validating all critical data on the server side, not trusting any data from the client, and using measures like server-side authorization checks, consistent re-computation of prices, and integrity protections (signing or binding critical fields to the user session) to ensure the data hasn’t been tampered with. Other options focus on different vectors: cookie tampering targets only cookies, while unvalidated input and file injection or command injection involve injecting malicious input into processing or system commands rather than altering in-transit parameters to change application state.