A remote code execution vulnerability exists in Windows Domain Name System servers when they fail to properly handle requests, aka 'Windows DNS Server Remote Code Execution Vulnerability'.
https://www.tenable.com/cyber-exposure/2020-threat-landscape-retrospective
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1350
http://packetstormsecurity.com/files/158484/SIGRed-Windows-DNS-Denial-Of-Service.html