To protect against attack, best practices must be applied to protect the DNS protocol, the server on which the DNS protocol runs, and all access to the DNS processes.
Implementing these best practices will not only protect DNS but also network security in general because properly protected DNS can also protect email, endpoints, and other network systems from attack.
DNS traffic inspection using next-generation firewalls, DNS firewalls, intrusion protection services, and anomaly detection can be used to protect against DNS tunneling and block malformed DNS queries used in DDoS attacks.
DNS filtering will often be included in the same tools that provide DNS traffic inspection as well as secure web gateways or DNS security services such as those from Cloudflare, Cisco Umbrella, Palo Alto DNS Security, and NS1. DNS Access Control.
These organizations will attempt to outsource as many DNS functions as possible to MSPs or DNS server solution providers such as Cisco Umbrella, Cloudflare DNS, Google Cloud DNS, or F5 Distributed Cloud DNS. However, even with many aspects outsourced, the organization bears the final responsibility to verify all service functions according to the terms of the agreement and satisfy all security and compliance requirements.
Even internal DNS servers need to follow the best practices to prevent a compromised device from intercepting DNS traffic or exploiting poorly protected local servers.
In addition to best practices, the local DNS servers should explicitly define and allowlist specific external DNS resolvers or DNS services.
Cloud-based DNS filtering and security services such as Cisco Umbrella, Palo Alto DNS Security, and NS1 protect the DNS process by tracking and blocking known malicious sources.
DNS cache poisoning hacks a local DNS server or a DNS resolver to replace IP addresses in the cache.
DNS flood DDoS attacks overwhelm a DNS server with UDP protocol DNS requests with an enormous volume.
DNS Flood DDoS attacks can be countered by hardening DNS servers against DDoS attacks, anti-DDoS services, and DNS firewalls.
These attacks effectively act the same as DNS cache poisoning but directly compromise the DNS records or DNS authoritative name server instead of only the cache.
DNS malformed query DDoS attacks overwhelm a DNS server with requests that have been intentionally misconfigured to increase the DNS server resources needed to process them.
DNS reflection-amplification DDoS attacks use bots to send DNS queries with spoofed IP addresses using the victim's IP address so that the DNS response will be sent to overwhelm the resource at that spoofed IP address.
DNS reflection-amplification DDoS attacks can be countered by hardening DNS servers against DDoS attacks, anti-DDoS services, and DNS firewalls.
DNS spoofing introduces forged DNS IP addresses into a DNS cache either through DNS cache poisoning or by impersonating a legitimate DNS server; similar to DNS hijacking but targets the cache, not the DNS record itself.
DNS Subdomain DDoS. DNS subdomain DDoS attacks overwhelm a DNS server with requests for non-existent URL subdomains.
DNS tunneling can be detected and blocked by inspecting DNS traffic, strictly controlling access to the DNS server, and by monitoring the IP address or domain to which the DNS information is sent.
Whether using outsourced DNS services, a modest internal-only DNS resolver, or a robust multi-function DNS architecture, an organization must recognize DNS as a mission-critical resource under regular attack.
To ensure secure and operational DNS functions, every organization should at least maintain best practices and, if possible, even better security for this critical IT service.
This Cyber News was published on www.esecurityplanet.com. Publication date: Fri, 08 Dec 2023 12:43:04 +0000