What is DNS security? Domain Name System (DNS) security refers to the technique of defending DNS infrastructure against cyber attacks. It ensures that your DNS infrastructure is operating efficiently and reliably. This requires establishing redundant DNS servers, using security technologies such as Domain Name System Security Extensions (DNSSEC), and mandating strict DNS registration.
A DNS is a collection of domain names and their associated IP addresses. It is often compared to a telephone directory, which connects people’s names to their telephone numbers. Similarly, a DNS ensures that a browser understands that when a user types cnn.com into the URL bar, for example, they are sent to the news company’s IP address, which is 22.214.171.124.
If a cybercriminal infiltrates a DNS system, they can send users to fake or malicious websites. They can also steal data, hijack websites, or flood servers with requests, eventually shutting them down. DNS security is designed to prevent these types of attacks.
How does DNS security work?
Since DNS is responsible for powering 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 increase network protection and improve the detection of malicious activity and compromised systems.
DNS security helps identify staging areas for rogue domains. To prevent infiltration and exfiltration attempts, such as DNS leaks, be sure to secure DNS servers and reject queries coming from staging sites on any port or protocol. If compromised devices connect to your network, DNS layer protection will stop any malware they might try to send. It also prevents callbacks from your DNS server to attackers who might be trying to hijack it. By interrupting this line of communication, DNS security prevents your DNS from being controlled and abused by hackers.
Why is DNS security important and how to achieve it?
By compiling a list of risky websites and filtering out unwanted content, DNS security solutions create an extra layer of security between the user and the Internet. As a result, your Domain Name System (DNS) will no longer be exposed to dangers or potentially harmful attacks.
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’s easier to maintain control over how your web assets are used, how they work, 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 example, you can use a next-generation firewall (NGFW) to resolve DNS security issues, taking some of the burden off your IT team. An NGFW can manage which sites on the Internet are allowed to interact with your network.
4 types of DNS attacks and how to avoid 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 inaccessible. They make the DNS servers that provide access unavailable to legitimate users.
This is how DNS amplification works. DNS uses the User Datagram Protocol (UDP) to transport information. An attacker can spoof the source address of a DNS request and direct the response to a specific IP address. This is because they can take advantage of the way UDP sends data packets over the Internet. Additionally, DNS responses are sometimes larger than the corresponding requests. By sending a small request to a DNS server and receiving a large response sent to the target, DDoS attackers can scale up — or “amplify” — their operations.
In a DNS spoofing scenario, fake DNS data is sent to the DNS resolver cache, causing the resolver to report a fake 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 uses a client-server model to smuggle malware and other data through the DNS protocol. The perpetrator purchases a domain such as badsite.com. The malware used to tunnel the traffic is placed on the attacker’s server. When the target’s server connects to the attacker’s website, the malware is transmitted, creating a tunnel between the malicious website and your DNS.
DNS hijacking refers to any attack that tricks a user into believing they are connecting to a trusted domain, even if they are actually connecting to a hostile website. This can be done by tricking a DNS server into storing inaccurate DNS data or by employing a compromised or malicious DNS server.
DNS x DNS Security x DNSSEC
DNS refers to your domain name server, which ensures users can connect to the correct IP address when typing 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 increase the security of your company’s network.
DNSSEC, or DNS Security Extensions, involves a set of specifications for authenticating DNS requests and responses using cryptography-based digital signatures. With DNSSEC, a DNS server ensures that the root nameserver is allowed to send a response and that the information contained in the response is secure. DNSSEC also ensures that the response has not been modified during transit.
4 Most Common DNS Security Extensions
The four most common DNS security extensions include:
- Cryptographic authentication of DNS data, which uses a symmetric key to provide access to DNS data.
- Response policy zones, use rules about what DNS queries can do.
- Authentication and data integrity, revolve around the use of cryptographically generated signatures, which are linked to your DNS resource records. This introduces cryptographic signature-based protection for all DNS queries because a query simply cannot be made without interfacing with a DNS resource record.
- Authenticated Denial of Existence (DoE). This enables the DNS resolver to determine whether a domain actually exists.
DNS security solutions to protect your business from DNS threats
Regardless of the type of attack, DNS security offers a comprehensive solution for protecting public and private DNS, protecting any system that depends on the secure and reliable operation of your website. By protecting your web assets with DNS security, you prevent attackers from disrupting your business, extorting payments in exchange for thwarting attacks, or stealing data from you or your customers.
How DNS Security Can Help Improve Security and Performance
Here are some DNS security best practices to keep your system safe from attackers.
Ensure 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 one primary and secondary DNS server to achieve the redundancy needed 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 takes over. When the primary DNS server is down, administrators can configure devices to use secondary DNS automatically. This is possible because any address within the IP range of a private network can act as the IP address of the internal DNS server.
If you achieve high availability of your DNS infrastructure by creating redundant DNS servers, your DNS records remain synchronized with the correct IP addresses. They will also be protected from failure because their redundancy system continually replicates and transmits data from their primary servers to secondary servers. This means that 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 byte of data. To increase security, start by making only the servers and information necessary for those who use them accessible. This is crucial if you need the public to be able to see your domain names.
Then hide your main DNS server. External users should not be able to see the primary servers. Specifically, there should be no publicly accessible nameserver databases that include data from these servers. End-user requests should only be handled by secondary DNS servers.
Top 5 DNS Security Trends
The five most popular trends driving DNS security include:
- DNS security is playing an essential role in protecting healthcare services.
- An increase in DNS security to protect against data exfiltration.
- DNS security will use whitelisting to reduce the chances of an attacker taking advantage of an organization’s IoT ecosystem.
- DNS security will be involved in protecting multi-cloud work environments due to the growth of hybrid work arrangements.
- The popularity of DNS security will continue to grow due to the number of high-profile attacks making headlines.
DNS Security Best Practices
Here are five best practices for improving your DNS security:
- Use DNS logging, which tracks client activity and tracks issues related to DNS queries.
- Block your DNS cache. Blocking the DNS cache involves controlling when people can access it. When the cache is locked, it is more difficult for hackers to sneak in and exploit the information stored within the cache.
- Filter DNS requests to block malicious domains.
- Set up access control lists, which involve only allowing administrators to access your domain name system.
- Use DNSSEC to validate the security of your DNS data. DNSSEC uses digital signatures to ensure that information received by clients is valid.
DNS security poses problems for corporate IT
Less than 31% of organizations are completely confident in the security of their DNS infrastructure, the EMA concludes.
Attacks related to Domain Name System infrastructure – such as DNS hijacking, DNS tunneling, and DNS amplification attacks – are on the rise and many IT organizations are questioning the security of their DNS infrastructure.
Most IT organizations maintain a variety of DNS infrastructures for public services (internet-accessible websites and services) and private services (Active Directory, file sharing, email). Securing internal and external DNS infrastructure is critical due to the growing number of threats and vulnerabilities that malicious actors use to attack them. Unfortunately, very few organizations are confident in the security of their DNS.
Enterprise Management Associates (EMA) recently examined the issue of DNS security in its recently published research report, “DDI Directions: DNS, DHCP, and IP Address Management Strategies for the Multi-Cloud Era.” Based on a survey of 333 IT professionals responsible for DNS, DHCP, and IP address management (DDI), the survey found that only 31% of DDI managers are completely confident in the security of their DNS infrastructure.
Top DNS Security Concerns
EMA asked survey participants to identify the DNS security challenges that cause them the most problems. The top answer (28% of all respondents) is DNS hijacking. Also known as DNS redirection, this process involves intercepting DNS queries from client devices so that connection attempts go to the wrong IP address.
Hackers often achieve this by infecting clients with malware so that queries go to a rogue DNS server, or by hacking a legitimate DNS server and hijacking queries on a more massive scale. The latter method can have a large blast radius, making it critical for companies to protect DNS infrastructure from hackers.
The second most concerning DNS security issue is DNS tunneling and exfiltration (20%). Hackers typically exploit this problem after they have already penetrated a network. DNS tunneling is used to avoid detection when extracting data from a compromised server. Hackers hide extracted data in outgoing DNS queries. Therefore, it is important for security monitoring tools to closely watch DNS traffic for anomalies such as abnormally large packets.
The third most pressing security concern is a DNS amplification attack (20%). This is a type of distributed denial of service (DDoS) attack in which a hacker tricks third-party, publicly addressable DNS servers into flooding a target DNS server with unwanted and spoofed query responses, overwhelming that server’s ability to respond. to legitimate consultations. This attack can make websites inaccessible because the end user’s DNS queries to the website cannot be resolved.
How to improve DNS security?
IT organizations can reduce DNS security risk by installing a DNS firewall. Nearly 47% of DDI experts told EMA that they implemented a DNS firewall to protect their infrastructure, and these organizations told us they were much more confident in their overall DNS security. DNS firewalls are specialized network security devices that focus entirely on inspecting DNS queries and blocking connections based on threat intelligence and security policies. They have much more granular visibility and intelligence into DNS traffic than a standard firewall.
Another important measure is the use of DNS Security Extensions (DNSSEC), a set of specifications created by the Internet Engineering Task Force (ETF). DNSSEC involves configuring DNS servers to digitally sign DNS records using public key cryptography. This allows other DNS servers to verify the authenticity of a DNS record and protects against forged and manipulated data. More than 47% of organizations investigated by the EMA extensively use DNSSEC. Those who do this have told us they are much more confident in their overall DNS security posture.
However, DNSSEC presents some challenges. DDI managers told the EMA that this could lead to increased infrastructure overload and increased management complexity. Some have also noticed flaws in DNSSEC’s overall security model.
Priority Security Policies for DNS
Nearly 38% of organizations are setting automatic security policies that prioritize DNS security threats. For example, they configure an intrusion prevention system to block DNS queries associated with known malicious IP addresses. Organizations using this technique told EM that they are more confident in DNS security.
Any DNS security strategy must also include the public cloud. Many DDI managers traditionally have DDI services for local networks. Cloud teams often adopt their own solutions for managing DNS, DHCP, and IP addresses in public cloud infrastructure. In recent years, DDI teams have been asserting themselves in the cloud to ensure that cloud networks are secure and stable.
“We try to work closely with the cloud team,” said a DDI engineer at a Fortune 500 consulting firm . “Five years ago this didn’t happen. There was a lot of risk. It’s easy to do things in the cloud without collaborating with network engineering and security. This can create problems.
EMA research found that nearly 59% of DDI teams now have sufficient influence over their companies’ cloud strategies. DDI professionals who had so much influence in the cloud were much more confident in their overall DNS security posture.
Finally, DDI teams need to see what is happening with the DNS infrastructure. Many companies typically export DNS logs to security information and event management (SIEM) platforms, where cybersecurity teams can look for anomalous activity. Furthermore, centralized monitoring of the entire DNS infrastructure is very important. Nearly 47% of DDI managers can monitor all DNS servers from a central console. These individuals were much more confident in DNS security.
Ways to Strengthen DNS Security
The domain name system (DNS) rose to prominence during the early, innocent days of the Internet. During this period, early Internet users tended to work for government or educational organizations where trust was assumed and security was not even considered. Because the online community was small and the Internet was little used, the importance of DNS was not widely understood and consequently left undefended.
Fast forward to today and you can see the resulting problems. Recent cyberattacks highlight specific techniques used by bad actors to intercept and manipulate a company’s legitimate web traffic, collect information such as credentials or email addresses, and carry out other malicious activities such as phishing.
In some cases, free digital certificates – which require low validation – were used to increase the credibility of scams, worsening the problem for brands and customers. Consumers are tired of their personal information being accessible and stolen by criminals; thus, breaches harm the reputation and bottom line of companies around the world. There is also the growing problem of distributed denial of service (DDoS) attacks, often targeting the DNS to paralyze online businesses.
For companies, the stakes are simple: no functional DNS means no website or Internet presence. If DNS fails, clients trying to visit a website simply won’t reach their destination. Employees will also not be able to send or receive company emails. If a business relies on VoIP to make and receive calls, access is cut off. If the DNS goes down, businesses will have to resort to using landlines and mobile devices to reach customers. Below are six ways to help strengthen DNS security.
Mitigate DDoS attacks with multi-layered protection
Volumetric DDoS attacks have exploded in size, with current attacks exceeding 1 Terra bit per second (Tbps). Some of the biggest attacks ever recorded have targeted the DNS.
There are several types of DDoS attacks targeting DNS
DNS amplification is one of many attack methods. In this attack, attackers exploit the large number of open DNS servers on the Internet, which can be used to respond to any and all small search queries with a spoofed IP of the target.
The target then receives much larger DNS responses that quickly overwhelm its capacity. The goal: block legitimate DNS queries by exhausting network capacity. Another common type of attack is DNS floods, which target DNS servers that host specific websites. They attempt to drain server-side assets, for example, memory or central processing unit (CPU), with a flood of User Datagram Protocol (UDP) requests, generated by running scripts on compromised botnet machines.
Multiple layers of DDoS protection
To defend against all types of DNS-based attacks, use a solution that comes with multiple layers of DDoS protection. DNS nodes must be equipped with DDoS mitigation equipment to constantly monitor malformed traffic as well as traffic from suspicious locations in higher than normal volumes. In many cases, mitigation happens locally.
If an attack is supersized, the malicious traffic must be automatically redirected to a mitigation network, a completely separate infrastructure built specifically for this purpose. This limits any potential damage to the destination nameserver IPs. With the impact isolated, a 24/7 security operations team is free to be more aggressive in its countermeasures.
Isolate name servers through segmentation
Across the industry, highly scalable DNS has become a cloud-based service with hundreds or thousands of clients – each with multiple domains – grouped into single networks and sharing a nameserver.
This increases the chances that you will feel someone else’s pain. If you use a third-party DNS provider, most attacks on their network will not target you, but a domain that shares your provider’s assigned nameserver.
It’s smart to isolate the impact of a DDoS attack
Choose a DNS provider that organizes the DNS network into segments, each with a name server advertisement shared only by a small group of customers. With fewer clients sharing hostnames and IP addresses, you face drastically lower chances of experiencing a ripple effect.
Imagine being in a large hall with 10,000 people and one person jumps up, shouting so loudly that no one can hear the speaker. Now imagine the same scenario but with just 20 more people. The screamer’s impact is limited to just 20. Assuming the screamer is a DDoS attack when the screamer (attack) begins, the name server segmentation and DDoS mitigation strategy instantly moves the entire room to a proof area sound by removing the well. behaved audience members and worked to drown out the screamer before bringing everyone else back. You can see how, with only 20 people, the screams affected fewer people who were easier to navigate during the attack.
Be protected if you or someone else is hit
This approach allows individual name server advertisements to pass from the DNS network to the DDoS mitigation network without significantly delaying query resolution. Your DNS provider must be able to provide immediate and effective mitigation for those who are under attack and prevent any collateral impact for customers who are still on the DNS network.
When using cloud-delivered DNS services, being on a targeted nameserver ad is an effective way to secure your DNS traffic.
Use a non-open source resolver
DNS resolvers – the servers that respond to domain name requests – ensure that users are routed to the correct websites. The most common software application used to manage DNS is Berkeley Internet Name Domain (BIND). Developed at the University of California at Berkeley in 1983, BIND still powers the vast majority of global name server implementations. Now completely in the public domain, BIND’s source code is open source and therefore readily available to be exploited and exploited by malicious hackers.
Avoid Resolver Threats
CSC chose to partner with Neustar because they solved this problem years ago. They developed proprietary code and asked third-party security auditors to look for vulnerabilities. They found nothing that attackers could remotely exploit, either to steal restricted privileges or make directory resolution difficult.
In addition to supporting standard DNS specifications and requests for comments (RFCs), they have enhanced their resolvers to extend DNS capabilities while providing extra redundancy and security. Most legacy DNS server implementations never come close.
Deploy DNS Security Extensions (DNSSEC)
As they help Internet users find the websites they need, DNS servers query each other. To speed things up, servers cache results for a specified period of time. If there is a query for the same name before the resource record expires, a server will provide the cached response rather than querying another machine.
DNS cache poisoning enables pharming attacks
While this improves efficiency, it also invites cache poisoning. This occurs when a DNS server, usually compromised by criminals, provides a false response to a DNS request. Users end up accessing fake websites that request personal information or simply activate malware. How can this happen? In many cases, DNS servers do not check whether the responses they receive from other servers are related to the original query. A server will cache incorrect information and pass it on to other DNS clients on the compromised machine.
The key to protection is DNSSEC
DNSSEC is a set of security extensions that authenticate DNS responses. The secret is a series of combinations of public and private keys for signing information resources. It works by providing a public key that allows the user’s resolver to confirm that a DNS response matches the cryptographic version. All transactions are signed – attackers cannot simply forge packets.
In the most basic terms, DNSSEC secures the DNS process, protecting against cache poisoning, pharming attacks, and other serious threats. Make sure you have this enabled. CSC cybersecurity reports show that in recent years there has been an alarmingly low DNSSEC adoption rate, ranging between 0% and 5% among large global companies across different industries.
Increase resiliency with a private DNS network
As the old security saying goes, you are only as strong as your weakest link. But what if you could improve your strength posture by eliminating weak links? By reducing dependence on public Internet connections, the private network has essentially eliminated the middle – and most dangerous – part of the DNS transaction, where the vast majority of DDoS attacks and DNS cache poisoning attempts occur. Ask if your provider offers this as an additional service.
A private network offers three main benefits:
Lower latency – In some cases, even if DNS is working perfectly, other Internet connection issues can cause DNS performance to degrade, leading to a poor user experience. The private network provides a fast and efficient online experience because DNS traffic bypasses the general Internet network.
Enhanced Security – Current Internet of Things-enhanced DDoS attacks that make the Internet inaccessible will soon become a thing of the past. A private network for DNS resolution on provider networks minimizes external threats such as DDoS attacks and cache poisoning attempts.
Improved reliability – In the event of a DDoS attack or significant outage, queries will continue to be resolved on the private networks where DNS is deployed. This resiliency ensures a superior Internet experience for users searching for websites and other vital online assets.
Leverage an intelligent dashboard to identify security blind spots for your vital digital assets
Companies need to be able to identify their business-critical domains and continuously monitor them to ensure they are protected with the right protections. Additionally, since new digital regulations such as the General Data Protection Regulation (GDPR) have been implemented, it is imperative to identify threats around vital domains and within the DNS infrastructure they reside on. This will help:
- Identify which domains are mission-critical and require a 100% DNS uptime guarantee
- Specify all current DNS providers and assess any security risks with the providers
- Identify any missing security features increasing the risk of DNS cache poisoning, domain or DNS hijacking, domain shadowing, DDoS, and phishing.
Overview – 10 secrets to improve DNS security
- Use dedicated DNS devices – If you host your own DNS servers, make sure you use the correct hardware. you must employ a dedicated DNS hardware device or open-source DNS software.
- Keep your DNS server software up to date – As with any other computer application, service, or protocol, new DNS vulnerabilities continually emerge. Attackers spend a lot of time discovering these weaknesses and figuring out how to exploit them. That’s why keeping your DNS server software up to date with current software versions and security updates is a task you can never permanently cross off your to-do list. Whether you find a dedicated device that applies updates for you or you have to apply them manually, you simply must stay on top of it.
- Have an on-site DNS backup – Even if you outsource your DNS to a managed DSN service provider, you must host your own dedicated backup DNS server. Neither ISPs nor managed DNS service providers are immune to attacks. In 2016, DNS service provider DYN and Internet service provider Deutsche Telekom were victims of massive DDoS attacks that caused widespread outages. A coordinated attack on your vendor isn’t the only reason to have a backup. Most commonly, hardware or network failures can cause slow DNS performance or interruption.
- Avoid single points of failure – A single point of failure is a part of your network that, if it stops working, shuts down the entire process. Eliminating single points of failure in any system or network is a basic principle of secure and resilient design. An important way to avoid single points of failure is to have multiple Internet links from different ISPs pointing to your sites. By introducing different ISPs, you increase the authoritative DNS servers that cache your links and reduce the risk of cache poisoning and diverting your visitors.
- Run authoritative DNS servers inside DMZs – If attackers are able to compromise an authoritative DNS server, they can change the DNS data of any domain for which that server is authoritative. The effect can be devastating. These changes are quickly replicated across the Internet and, in some cases, take days to correct. Stop these problems before they start by configuring your authoritative DNS servers within a secure network demilitarized zone (DMZ). DMZ allows you to import DNS records only from a secure primary server that is also located within your DMZ.
- Disable recursion – As much as possible, you want to control who can request information from your authoritative DNS server. You can restrict zone transfers to specific IP addresses from your secondary DNS servers, for example, to prevent attackers from obtaining hostnames and IP addresses for your network. For another example, you can digitally sign your zone transfer records to prove their authenticity
- Use Threat Intelligence – Threat intelligence is information about the weakest points in your network and the most likely attacks you are likely to receive. You can use this information to make decisions and set priorities on how to protect your business.
- Use response policy zones – A response policy zone (RPZ) allows you to define policies for specific domains.
- Use IPAM – As your network grows, even maintaining visibility into everything becomes a challenge. With an enterprise-grade IP address management (IPAM) solution, you can consolidate information about your core network infrastructure into a comprehensive, reliable database. This solution allows you to see the entire topology of your network.
- Automate security tasks whenever possible – Tasks that you can automate with DNS security software include many common scenarios:
- When your DNS security solution detects DNS-based data exfiltration or malware from an infected host, it must notify an endpoint security solution to clean the infected endpoint.
- When a new device joins the network, your DNS security solution should trigger a vulnerability scan.
- Until vulnerability scanning and mediation of any issues are complete, your DNS security solution should trigger a network access control (NAC) solution to prevent the endpoint from entering the network until it is in compliance.
You can also count on an IT company to assist with DNS security, customizing it to the real needs of your business.