This instance of openly-registerable nameservers is just one (relatively rare) subset of a wide class of dangling DNS issues [1].
Much more common is direct mapping of names to IP addresses on cloud providers that can be obtained by attackers [2][3]. Because of the scope and lack of global visibility that often comes with cloud services, an enterprise that uses is the cloud is very likely to have some vulnerabilitity like this under some subdomain.
Unfortunately bug bounty programs often blanket exclude any form of "subdomain takeover" as a valid security threat, despite the fact that they're easily exploitable once discovered. We have internal (and public[4]) data showing all manner of sensitive information leaked as a result of this sort of configuration mismanagement.
Ultimately, as others have observed, the current vulnerability disclosure landscape makes it far too easy for corporations to weasel out of acknowledging bona fide vulnerabilities, and of course ethical and legal expectations make it impossible for good-faith researchers to meet the bar of proof expected by these providers.
To others' comments: yes, these vulnerabilities are trivially exploited to provision TLS certificates in practice, a risk that is unfortunately downplayed.
[1] https://dl.acm.org/doi/pdf/10.1145/2976749.2978387 [2] https://escholarship.org/content/qt9r59r676/qt9r59r676.pdf [3] https://pauley.me/post/2022/cloud-squatting/ [4] https://arxiv.org/pdf/2204.05122
Think:
* CNAME pointing to an S3 bucket, and the S3 bucket gets released
* CNAME pointing to Azure Website/WebApp Instance
* A record to an non-elastic IP, and the box gets rebooted
* DNS name using a Route53 name server that no longer part of the org's AWS account
* CNAME pointing to a Heroku/Shopify/GitHub pages account and the account gets deleted/deactivated freely up those names for registration
* MX record pointing to old transaction email provider start up that dies, and someone else registers that domain name...
Why does that happen?
* Decentralization of IT means people spinning up infrastructure not knowing what they are doing
* Great a spinning up infra, but when decomissioning they forget about DNS
* Lots of subsidiaries, lots of brands, different groups, operating in different geographies. All this makes it difficult to discover and enforce proper policies
* Geo-specific websites/apps (Think of all the country-specific websites Coke runs)
* Using some 3rd party vendor and never telling security about it (Marketing spinning up some landing pages on some fly-by-night martech provider or wordpress host, and never turning them off)
I am the Field CTO at a venture backed Israeli cyber security company in this space. I was literally talking to a major computer part company yesterday about the dozen or so Indonesian gambling websites that are "running" on their domain names using their pagerank and links. This is a weekly conversation
This sounds as if it should be more differentiated by how easy the domain would be able to obtain.
Like, it's obvious that "If I somehow took over google.com, I could compromise Google users" is no valid security vulnerability. But if taking over unregistered (or lapsed) domains results in a compromise, as demonstrated here, this should be seen as a valid vulnerability.