DNS poisoning can accomplish which outcome?

• A. Redirect traffic from a legitimate website to a malicious one by corrupting the DNS cache.
• B. Increase DNS cache size.
• C. Improve DNS security.
• D. Authenticate DNS responses.

Answer: (A)

DNS poisoning works by tampering with the data that maps domain names to IP addresses in the DNS system. When a user tries to reach a site, their resolver asks for the domain’s IP and stores the answer in a cache. If an attacker can inject a forged response that looks legitimate and arrives first, the resolver may cache the attacker’s IP address. Later requests for that domain return the malicious address, so users end up visiting the attacker’s site instead of the legitimate one. This is precisely how traffic can be redirected to a malicious site.

The other options don’t fit because DNS poisoning isn’t about increasing cache size, it doesn’t improve security, and it doesn’t provide authenticated responses. Authentication of DNS data, when available, comes from mechanisms like DNSSEC, which poisoning undermines rather than enables.