Attackers have started exploiting a flaw in the most widely used software for the DNS (Domain Name System) The flaw can be exploited with a single packet, crashing both authoritative and recursive DNS servers. The flaw affects all versions of BIND 9, open-source software originally developed by the University of California at Berkeley in the 1980s. There’s no workaround for the flaw, so administrators need to patch to stop attacks. At least two of Sucuri’s clients within different industries had seen their DNS servers crash due to attacks.”]
Source: https://www.csoonline.com/article/2955914/dns-server-attacks-begin-using-bind-software-flaw.html