Why DNS security ?
DNS security has equal importance that of DNS. So we should bother about DNS security also.
While transferring standard DNS queries, which are essential for almost all website traffic and it will create a chance for DNS exploits like DNS hijacking and on-path attacks.
These types of DNS based attacks can perform redirect website traffic to other fake copies of sites. It will lead to stealing user’s sensitive information and hence reduces your site’s reputation.
Types Of Common DNS Attacks :
- DNS Spoofing (Or) Cache Poisoning :
This is an attack that causes DNS resolvers cache and it will redirect the website traffic to the site with another incorrect IP (destination).
2. DNS Tunneling :
DNS tunneling will pass network protocols like SSH, TCP, HTTP into DNS queries to bypass malware (or) stealing the sensitive information.
3. DNS Hijacking :
Through this attack, will redirect the DNS queries to a different domain name server. It can be done by unauthorized modification or by using malware.
4. NXDOMAIN Attack :
This is a process of DDOS attack on a DNS authoritative server with the non-legitimate domain’s junk requests to force a response. (Eg: asking for a record that doesn’t exist.)
These attacks will create lots of junk mails in the resolver’s cache.
5. Phantom Domain Attack :
The Phantom Domain attack has a similar result to the NXDOMAIN attack on a DNS resolver.
The attacker creates a group of “phantom” domain servers that either respond to the requests (slowly or not at all). Then it will create hitting of several requests to these types of domains from the resolver. It will lead to bad performance and can cause Denial-of-service.
6. Random Subdomain Attack :
The goal of this attack is to create a denial-of-service for a domain’s authoritative name server by making it is impossible to look up the domain from that name server.
For this, the attacker sends several random DNS queries, non-existing subdomain which belongs to a legitimate site.
7. Domain Lock-Up Attack :
This type of attack setups special domains and resolvers to establish TCP connections with other legitimate resolvers. Hence the target resolvers send requests and these domains respond with slow random packets, trying to lock up the resolver’s resources.
8. Botnet-Based CPE Attack :
These attacks are processed by CPE ( Customer Premise Equipment), for example, modem, router, etc. The attackers will make the CPE devices a part of the botnet and use them for performing random subdomain attacks against one site or resource.
How Can Prevent DNS Attacks ?
- DNSSEC
The Domain Name System Security Extensions (DNSSEC) is one of the best security protocols which is used to prevent DNS attacks.
DNSSEC protects against DNS attacks by digitally signing the data to make sure of it’s validity.
For making a secure lookup, this signing must occur at every DNS lookup process level .It uses a hierarchical digital signing policy through all DNS layers.
DNSSEC is also works with other security measures such as SSL/TLS.
This protocol will create a parent-child chain of trust that will process up to the “root zone”. This chain of trust will not break any layer of DNS, otherwise, it will lead to an “open-path attack”.
How DNSSEC Works ?
DNSSEC operates similarly to TLS/ HTTPS by using the public/ private key pairs to sign the DNS records. The process includes,
- DNS records will sign with the public/private key pairs.
- This DNSSEC queries response contain both record that was requested with public key signature.
- The public key then compare the DNS record and its signature for authentication.
2. Anycast Routing
This tool can prevent DDOS attacks by allowing multiple servers to share a single IP address, so that when a DNS server went down then the other servers will up and serve.
3. DNS Firewall
A DNS Firewall uses between the user’s recursive resolver and the authoritative nameserver of the domain or service they are looking to connect.
We can set rate-limiting services using this type of DNS firewall to shutdown attackers that is trying to access the server.
This firewall will also provide a DNS cache service,to serve the domain’s content if in case of the domain has experienced a downtime.
DNS Firewall can also provide faster DNS lookups and reduced bandwidth costs for DNS operators.
4. Using DNS as a Security Tool
Some of the DNS resolvers providing features like content filtering, it will help to block sites known to inject malware, spam, and botnet protection.
Cloudflare like DNS provider has these type of features.
5. DNS over TLS and DNS over HTTPS
These are two methods of encrypting DNS queries.
DNS over TLS (DoT) method uses TLS (Transport Layer Security) to encrypt the UDP traffic of DNS queries.
DNS over HTTPS or DoH is an experimental protocol powered by Mozilla and Google, which will encrypt the DNS resolution requests over the HTTPS connection.
The main difference between these two standards is, in DoT, the original DNS protocol doesn’t change. While in DoH, it encapsulates the DNS in HTTP format before requests are transferring.
Securing DNS service for your domain has a vital role in your business. Our server experts are available 24/7 for your all queries.
