DNS Security
DNS security encompasses the practices, protocols, and tools used to protect the Domain Name System from attacks such as spoofing, cache poisoning, tunneling, and hijacking that exploit DNS vulnerabilities.
The Domain Name System is a foundational internet protocol that translates human-readable domain names into IP addresses. Because DNS was not originally designed with security in mind, it is vulnerable to numerous attacks. DNS spoofing and cache poisoning allow attackers to redirect users to malicious sites. DNS tunneling encodes data within DNS queries to exfiltrate information or establish covert communication channels. DNS hijacking modifies name resolution to redirect traffic.
DNSSEC (DNS Security Extensions) addresses some of these risks by adding cryptographic signatures to DNS records, allowing resolvers to verify the authenticity of responses. However, DNSSEC adoption remains incomplete across the internet. Additional protective measures include DNS-over-HTTPS (DoH) and DNS-over-TLS (DoT), which encrypt DNS queries to prevent eavesdropping and manipulation in transit.
Organizations should implement DNS filtering to block access to known malicious domains, monitor DNS query logs for anomalous patterns indicative of tunneling or data exfiltration, deploy DNSSEC where possible, use reputable DNS resolvers, and maintain up-to-date DNS server software. Integrating DNS telemetry into security monitoring platforms provides valuable threat intelligence and early warning of compromise.