In this paper, the authors conduct an analysis of the
previously over-looked attack surface related to DNS, and are able
to uncover even stronger side channels that have existed for over a
decade in Linux kernels. The side channels affect not only Linux
but also a wide range of DNS software running on top of it,
including BIND, Unbound and dns-masq. They also discovered that
about 38% of open resolvers (by frontend IPs) and 14% (by backend
IPs) are vulnerable including the popular DNS services such as
OpenDNS and Quad9.
Read more https://packetstormsecurity.com/files/164989/ccs21_dns_poisoning.pdf