Amazon and Google Patch Major Bug in Their DNS-as-a-Service Platforms

At the Black Hat security conference Wednesday, two security researchers have disclosed a security issue impacting hosted DNS service providers that can be abused to hijack the platform’s nodes, intercept some of the incoming DNS traffic, and then map customers’ internal networks. From a report: Discovered by Shir Tamari and Ami Luttwak from cloud security company Wiz, the vulnerability highlights the amount of sensitive information collected by managed DNS platforms and their attractiveness from a cyber-espionage and intelligence data collection standpoint.

Also known as DNS-as-a-Service providers, these companies effectively rent DNS servers to corporate entities. While it’s not hard to run your own DNS name server, the benefit of using a service like AWS Route53 or the Google Cloud Platform is that companies can offload managing DNS server infrastructure to a third-party and take advantage of better uptime and top-notch security. Companies that sign up for a managed DNS provider typically have to onboard their internal domain names with the service provider. This typically means companies have to go to a backend portal and add their company.com and other domains to one of the provider’s name servers (i.e., ns-1611.awsdns-09.co.uk). Once this is done, when a company employee wants to connect to an intranet app or an internet website, their computer will query the third-party DNS server for the IP address it needs to connect. What the Wiz team discovered was that several managed DNS providers did not blacklist their own DNS servers inside their backends.