In terms of web security, what does validating a webhook signature help to prevent?

Validating a webhook signature is crucial for ensuring that the data received from a webhook is authentic and has not been tampered with. When a webhook is set up, the provider usually includes a signature in the HTTP headers or body of the request. This signature is generated using a secret key that only the sender and the receiver know.

By validating this webhook signature, the application can confirm that the incoming request actually originated from the expected source, thus preventing the risk of unauthorized access. If an attacker were to attempt to spoof the webhook by sending fraudulent data, the server would be unable to generate a matching signature, leading to a rejection of the request. This validation acts as a safeguard against impersonation and ensures that only legitimate requests interact with the system, thereby maintaining the integrity of the application and its data.

The other options, while important aspects of overall web security, do not directly relate to the primary purpose of webhook signature validation. For example, data leaks and malware infections involve broader security issues that require different security measures, and while denial of service attacks can affect a service’s availability, they aren't directly mitigated through the process of validating webhook signatures.