What type of attack involves sending false requests to DNS servers with a forged source IP?

A DNS amplification attack involves sending false or forged requests to DNS servers using a fake source IP address. The attacker exploits publicly available DNS servers by sending a small query that triggers a larger response from the DNS server. Because the source IP address in the request is forged, the response is sent to an unsuspecting victim's IP address rather than the attacker's. This approach amplifies the network traffic directed at the target, potentially overwhelming it and causing a denial of service.

The key aspect of this attack type is its efficiency; a small, simple query can result in a significantly larger response being sent to the victim. This kind of exploitation relies heavily on the trust that DNS servers place in requests that come from any source, which makes them vulnerable to being abused in this way.

Other types of attacks mentioned, such as brute-force attacks, man-in-the-middle attacks, and dictionary attacks, do not involve sending forged requests to DNS servers nor do they exploit DNS functionality in the same way. A brute-force attack is typically associated with trying various passwords or encryption keys to gain access to a system, while a man-in-the-middle attack involves intercepting communications between two parties. Similarly, a dictionary attack focuses on using a list of potential passwords to compromise an account.