DNS Security: Why does it matter?
It may come as a surprise, but the website address on its own isn’t really enough to reach the website. Computers operate on internet protocol addresses, not URLs. To make users’ life easier, there is a built-in domain name system that functions like a phonebook, and computers consult it to find IP addresses to connect to websites. However, this phonebook is also one of the network’s biggest vulnerabilities. Hackers can exploit this system to redirect users to spoofed websites. For this reason, DNS security should be one of the priorities when securing an organization against various cyber threats.
What is DNS Security?
DNS security is the practice of protecting DNS infrastructure from cyber attacks in order to keep it performing quickly and reliably. An effective DNS security strategy incorporates a number of overlapping defenses, including establishing redundant DNS servers, applying security protocols like DNSSEC, and requiring rigorous DNS logging.
How does it 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.
The Importance of DNS Security
DNS is an old protocol, and it was built without any integrated security. Several solutions have been developed to help secure DNS, including:
- Reputation Filtering: Like any other Internet user, most malware needs to make DNS requests to find the IP addresses of the sites that it is visiting. Organizations can block or redirect DNS requests to known malicious domains.
- DNS Inspection: The use of DNS for data exfiltration via DNS tunneling or security evasion using Domain Generation Algorithms can also be detected and blocked in real-time by next-generation firewalls (NGFW) that leverage threat intelligence powered by AI Deep Learning engines. This helps to block even sophisticated malware that uses DNS for malware command and control (C2) communications and other attacks.
- Secure the Protocol: DNSSEC is a protocol that includes authentication for DNS responses. Since the authenticated response cannot be spoofed or modified, attackers cannot use DNS to send users to malicious sites.
- Secure the Channel: DNS over TLS (DoT) and DoH (DNS over HTTPS) add a secure layer to an insecure protocol. This ensures that the requests are encrypted and authenticated, unlike traditional DNS. By using DoH and DoT, a user can ensure the privacy of DNS responses and block eavesdropping on their DNS requests (which reveals the sites that they are visiting).
DNS security risks
DNS attacks are among the most prevalent and effective web security threats. Let’s discuss more about them. Below are common DNS attack types.
- DoS: A denial-of-service (DoS) attack aims to bring down a computer system or network so that its intended users are unable to access it. DoS attacks achieve this by sending the target an excessive amount of traffic or information, causing it to crash. Malicious actors that employ DoS attacks frequently target the web servers of well-known companies in industries like media, banking, and commerce, as well as governmental and commercial organizations.
- DDoS: A distributed denial-of-service (DDoS) attack takes place when multiple systems coordinate a synchronized DoS attack against a target. Therefore, the main distinction from DoS is that the target is attacked simultaneously from multiple spots rather than just one. DDoS attacks can affect the customer experience and workflow, but also the revenue and brand reputation.
- DNS hijacking: Attackers use DNS hijacking, also known as DNS redirection, to direct users to malicious websites by misresolving DNS requests. If malicious players control a DNS server and direct traffic to a fake DNS server, the fake DNS server will then translate a valid IP address into the IP address of a malicious site.
- Other indirect attacks: The critical importance of DNS security is underscored by the fact that other forms of cyberattacks may use DNS as a tool or be tools used by hackers to compromise the DNS. Man-in-the-middle attacks, along with bot and zero-day attacks, are the most crucial to mention in this context.
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.
DNS Security is a vital part of any organization’s security infrastructure. It protects the integrity of the internet by ensuring that the DNS is stable and secure. The best thing you can do to protect your business from data breaches is to make sure that your DNS server has a firewall enabled and that it’s configured to reject any requests from outside your network.
DNS security components include firewalls and access control lists and keep your data safe from unauthorized access and hackers by controlling who can get in and what they can do when they are inside. It is important to keep these systems up-to-date with the latest security protocols so that you can prevent cyber-attack.