Why is DNS security important?
DNS was designed in the 1980s when the Internet was much smaller and trust between participants was assumed. As a result, DNS lacks built-in security mechanisms, making it vulnerable to various attacks including DNS spoofing, cache poisoning, and DDoS attacks against DNS infrastructure.
Common DNS security threats
- DNS spoofing / cache poisoning: Corrupting DNS resolver caches to redirect users to malicious sites
- DNS tunneling: Using DNS queries to exfiltrate data or bypass firewalls
- DNS amplification attacks: Exploiting open DNS resolvers to amplify DDoS attacks
- Domain hijacking: Unauthorized changes to a domain's DNS records
DNSSEC
DNS Security Extensions (DNSSEC) adds cryptographic signatures to DNS records, allowing resolvers to verify that responses have not been tampered with. DNSSEC creates a chain of trust from the root zone down to individual domain records.