CVE-1999-1233
IIS 4.0 does not properly restrict access for the initial session request from a user’s IP address if the address does not resolve to a DNS domain, aka the "Domain Resolution" vulnerability.
Date published : 2002-03-09
http://www.securityfocus.com/bid/657
https://docs.microsoft.com/en-us/security-updates/securitybulletins/1999/ms99-039