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What Is DNS Security?

DNS Security Definition

What is DNS security? Domain Name System (DNS) security refers to the technique of defending DNS infrastructure from cyberattacks. It ensures your DNS infrastructure is operating efficiently and reliably. This requires establishing redundant DNS servers, using security technologies like Domain Name System Security Extensions (DNSSEC), and mandating stringent DNS logging.

A DNS is a collection of domain names and their associated IP addresses. It is often compared to a phone book, which connects the names of people with their phone numbers. Similarly, a DNS ensures a browser understands that when a user types in cnn.com in the URL bar, for instance, they get sent to the news company’s IP address, which is 157.166.226.25.

If a cybercriminal infiltrates a DNS system, they can send users to fake or malicious sites. They can also steal data, hijack websites, or inundate servers with requests, shutting them down eventually. DNS security is designed to prevent these kinds of attacks.

How Does DNS Security Work?

Since DNS is responsible for enabling all internet activity, keeping an eye on DNS requests and the IP addresses they lead to can help keep your network secure. Having security policies in place to highlight unusual DNS behavior can boost network protection and improve the detection of malicious activity and compromised systems.

DNS cybersecurity helps pinpoint the staging areas for rogue domains. To stop both infiltration and exfiltration attempts, such as a DNS leak, make sure to secure DNS servers and reject queries arriving from staging sites over any port or protocol. If compromised devices connect to your network, DNS-layer protection stops any malware they may try to send. It also prevents callbacks from your DNS server to the attackers who may be trying to hijack it. By interrupting this line of communication, DNS security prevents your DNS from being taken over and abused by hackers.

How DNS Security Works

Why Is DNS Security Important and How To Achieve It?

By compiling a list of risky websites and filtering out undesired content, DNS security solutions create an extra layer of security between a user and the internet. As a result, your Domain Name System (DNS) will no longer be exposed to dangers or potentially harmful assaults.

You can think of your DNS as the heart of your web presence, which makes it a valuable target for attackers. By keeping it protected, it is easier to maintain control over how your web assets are used, how they function, and which sites are allowed to communicate with them.

To achieve DNS security, you need a solution provided by a qualified security hardware or software company. For instance, you can use a next-generation firewall (NGFW) to address DNS security issues, removing some of the burden from your IT team. An NGFW can manage which sites on the internet are allowed to interface with your network.

4 DNS Attack Types and How to Prevent Them

Here are four of the most common DNS security vulnerabilities and how to prevent attackers from taking advantage of them.

DoS, DDoS, and DNS Amplification Attacks

By flooding networks with what appears to be legal traffic, denial-of-service (DoS) and distributed denial-of-service (DDoS) attacks on DNS systems can render websites unreachable. They make the DNS servers that provide access unavailable to legitimate users.

This is how DNS amplification works. DNS uses User Datagram Protocol (UDP) to transport information. An attacker can fake the source address of a DNS request and direct the answer to a specific IP address. This is because they can take advantage of how UDP sends data packets through the internet. Furthermore, DNS answers are sometimes bigger than matching requests. By submitting a small request to a DNS server and having a large response sent to the target, DDoS attackers can scale up—or “amplify”—their operations.

DNS Spoofing

In a DNS spoofing scenario, fake DNS data is sent to the DNS resolver's cache, causing the resolver to report a false IP address. Traffic will be redirected to a malicious domain. As a result, your website address can be used for malicious purposes, such as distributing viruses or stealing login credentials.

DNS Tunneling

DNS tunneling uses a client-server model to smuggle malware and other data through the DNS protocol. The perpetrator buys a domain like badsite.com. Malware used for tunneling traffic is placed on the attacker's server. When the target’s server connects with the attacker’s site, the malware gets transmitted, setting up a tunnel between the malicious site and your DNS.

DNS Hijacking

DNS hijacking refers to any attack that deceives a user into believing they are connecting to a trustworthy domain even though they are actually connected to a hostile site. This can be done by tricking a DNS server into storing inaccurate DNS data or by employing a compromised or malicious DNS server.

DNS vs. DNS Security vs. DNSSEC

DNS refers to your domain name server, which ensures that users can connect to the right IP address when they type in a URL, such as Google.com. DNS security is different. Unlike DNSSEC, which involves a specific method, protocol, or extension, DNS security is a concept. At the most fundamental level, it refers to using DNS data to enhance the security of your company network.

DNSSEC, or DNS Security Extensions, involves a set of specifications for authenticating DNS requests and responses using digital signatures based on cryptography. With DNSSEC, a DNS server makes sure the root name server is permitted to send a response and that the information in the response is safe. DNSSEC also ensures that the response was not modified while in transit.

DNS Security Solutions to Protect Your Business from DNS Threats

Regardless of the kind of attack, DNS security offers a comprehensive solution to safeguarding both public and private DNS, protecting any system that relies on your website’s secure and reliable operation. By safeguarding your web assets with DNS security, you stop attackers from interrupting your business, extorting payments in exchange for stopping attacks, or stealing data from you or your customers.

How DNS Security Can Help Enhance Security and Performance

Here are some DNS security best practices to keep your system safe from attackers.

Make Sure Your DNS Is Available by Incorporating Redundancy

Your DNS infrastructure needs to be highly available because DNS is the foundation of network applications. You must have at least a primary and secondary DNS server to achieve the redundancy necessary to ensure the availability of business-critical services. All email, file sharing, and Active Directory services depend on reliable DNS performance.

How Redundancy Protects Your Network

When one DNS server encounters a problem, the other one takes over. When the primary DNS server is down, administrators can configure devices to use the secondary DNS automatically. This is possible because any address inside a private network's IP range can act as the internal DNS server's IP address.

If you achieve high availability of the DNS infrastructure by creating redundant DNS servers, your DNS records will remain in sync with the correct IP addresses. They will also be secure from failure because your redundancy system continuously replicates and transmits data from your primary to secondary servers. This means end users will always have access to your web services.

Hide DNS Information and Servers

Not all users need access to every DNS server or every single byte of data. To enhance safety, start by making only the servers and the information required for those using them accessible. This is crucial if you need the public to be able to see your domain names.

Next, hide your main DNS server. External users should not be able to see primary servers. Specifically, there should not be any publicly accessible nameserver databases that include the data for these servers. Requests from end users should only be handled by secondary DNS servers.

How Fortinet Can Help?

With a FortiGate Next-Generation Firewall (NGFW), you can filter out malicious websites that can be used to compromise network security. Powered by threat intelligence from FortiGuard Labs, FortiGate can identify which sites pose a threat and block all requests coming from them. You can also use FortiGate as a secondary DNS server, as described above. This puts a wall between your primary DNS server and potential attackers. By hiding your main DNS server behind a FortiGate NGFW, you build a security perimeter that protects your organization from attackers and various types of malware.

FAQs

Why is DNS security important?

By compiling a list of risky websites and filtering out undesired content, DNS security solutions create an extra layer of security between a user and the internet. As a result, your Domain Name System (DNS) will no longer be exposed to dangers or potentially harmful assaults.

How does DNS security work?

DNS security pinpoints the staging areas for rogue domains. To stop both infiltration and exfiltration attempts, secure DNS servers reject queries arriving from these staging sites over any port or protocol. If compromised devices connect to your network, DNS-layer protection stops any malware they may try to send. It also prevents callbacks from your DNS server to the attackers who may be trying to hijack it.