When most organizations discuss cybersecurity, the conversation often revolves around firewalls, endpoint detection, and Zero Trust architecture. Yet beneath every connection request, authentication handshake, and encrypted session lies one foundational system: the Domain Name System (DNS). It is the translator that turns human-friendly URLs into IP addresses computers can understand. Despite its importance, DNS security remains one of the most neglected aspects of enterprise defense.
Why DNS Security Matters
DNS was designed in the early days of the Internet, long before cybersecurity was a core concern. Its original creators prioritized reliability and accessibility, not protection. As a result, DNS operates largely on trust — and attackers have spent decades exploiting that fact.
Modern cyberattacks frequently target or manipulate DNS to achieve their goals. Whether through DNS hijacking, cache poisoning, or tunneling, adversaries exploit the protocol’s open design to redirect users, steal data, and conceal malicious activity. Because nearly every digital transaction depends on DNS resolution, a single weakness in this layer can undermine even the most mature security programs.
For federal contractors and organizations working toward CMMC 2.0 compliance, the implications are clear. Both Controlled Unclassified Information (CUI) and Federal Contract Information (FCI) rely on secure transport and reliable authentication. If DNS traffic is compromised, those protections collapse before encryption or endpoint controls even come into play. The Defense Department’s cybersecurity maturity framework expects organizations to manage network boundaries and control communications, which includes securing the DNS layer.
Common DNS Attack Methods
DNS Spoofing and Cache Poisoning: Attackers insert forged DNS data into a resolver’s cache, sending users to fraudulent destinations instead of legitimate sites. This tactic is often used for credential theft or malware distribution.
DNS Tunneling: Data exfiltration through DNS queries and responses allows threat actors to bypass traditional network controls. Since DNS traffic is often trusted and rarely inspected, tunneling can persist undetected for long periods.
DNS Hijacking: Adversaries modify DNS records or redirect queries through unauthorized servers. This technique enables surveillance, phishing, or traffic redirection to malicious infrastructure.
NXDOMAIN and Random Subdomain Attacks: Flooding a DNS server with requests for nonexistent or randomized subdomains can overwhelm resources, causing denial-of-service conditions that disrupt business operations.
Phantom Domain and Lock-Up Attacks: Slow or non-responsive domains are used to tie up resolver resources, degrading performance and limiting access to legitimate sites.
Each of these tactics targets a fundamental flaw in DNS’s design: its lack of inherent verification and encryption.
Building a Resilient DNS Layer
Defending DNS infrastructure requires a combination of architectural redundancy, protocol enforcement, and active monitoring.
1. DNSSEC Implementation
DNS Security Extensions (DNSSEC) digitally sign DNS data to ensure its authenticity. When properly deployed, DNSSEC prevents forged or tampered DNS responses from being accepted. It establishes a “chain of trust” from the root zone to each subdomain, verifying that every lookup is legitimate.
2. Redundancy and Load Balancing
Establishing multiple redundant DNS servers across regions reduces the risk of single points of failure. Load balancing ensures availability even during high-traffic events or distributed denial-of-service (DDoS) attempts.
3. DNS Firewalls and Filtering
A DNS firewall can inspect, filter, and rate-limit DNS requests. By analyzing traffic patterns and enforcing reputation-based blocking, DNS firewalls help contain malware command-and-control traffic and phishing redirections before they reach the endpoint.
4. Logging and Continuous Monitoring
Rigorous DNS logging allows for early detection of abnormal activity, such as unusual query volumes or outbound requests to rare domains. Integrating DNS telemetry into SIEM or SOAR tools gives SOC analysts visibility into emerging threats before they escalate.
5. Encryption of DNS Queries
Protocols like DNS over HTTPS (DoH) and DNS over TLS (DoT) add privacy and integrity by encrypting DNS requests. This prevents external actors, including threat actors or nation-state monitors, from intercepting or modifying DNS queries in transit.
DNS in the Context of CMMC 2.0
Under CMMC 2.0, protecting FCI and CUI requires a layered defense strategy that accounts for every communication path. DNS security directly supports multiple CMMC controls related to system communication protection, boundary defense, and audit logging.
For example:
- AC.L1-3.1.20 (Verify and control connections to and from external systems) is directly impacted by whether DNS queries are trusted and validated.
- AU.L2-3.3.1 (Create and retain system audit logs) requires that DNS activity be monitored and recorded.
- SC.L2-3.13.1 (Monitor, control, and protect communications) includes DNS-based communication channels that could otherwise be used for exfiltration.
Neglecting DNS security means leaving a blind spot in the compliance framework — one that adversaries have repeatedly proven willing to exploit.
Why DNS Is Still Overlooked
Despite its central role, DNS security often falls through organizational cracks. It’s frequently managed by network engineers rather than security teams, and it’s rarely included in broader vulnerability management programs. Many organizations treat DNS as a “set-and-forget” service until something goes wrong.
This separation creates risk. Without integrated governance between IT and security, DNS configurations can become outdated, unmonitored, or vulnerable to misconfiguration. Adversaries exploit this complacency because compromising DNS can be faster and quieter than breaching a firewall or endpoint.
The Path Forward
The foundation of a secure enterprise begins with securing DNS. By embedding DNS security within Zero Trust architectures, enforcing encryption for queries, and integrating DNS telemetry into SOC operations, organizations can detect and block threats long before they reach the user. The DoD has made it clear that safeguarding CUI and FCI requires visibility into every communication layer. That starts with DNS.
How Netizen Helps
Netizen’s 24x7x365 Security Operations Center (SOC) continuously monitors client environments for DNS-based threats, identifying spoofing, tunneling, and hijacking activity in real time. By integrating DNS telemetry with behavioral analytics, Netizen’s analysts can correlate intent-based activity across endpoints and networks to detect adversarial patterns early.
As a Service-Disabled Veteran-Owned Small Business (SDVOSB) with ISO 27001, ISO 9001, ISO 20000-1, and CMMI Level III certifications, Netizen supports government, defense, and commercial organizations in maintaining secure and compliant environments. Our expertise in CMMC 2.0 readiness and network monitoring helps clients safeguard both FCI and CUI while maintaining operational continuity.
With Netizen’s SOC monitoring your DNS infrastructure, your organization gains the visibility, protection, and assurance needed to keep the foundation of your network secure.
Looking for expert guidance to secure, automate, and streamline your IT infrastructure and operations? Start the conversation today.
