By default, IIS 4.0 has a virtual directory /IISADMPWD which contains files that can be used as proxies for brute force password attacks, or to identify valid users on the system.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-1999-0407
Reference (s):
- BUGTRAQ:19990209 ALERT: IIS4 allows proxied password attacks over NetBIOS
- URL: http://marc.info/?l=bugtraq&m=91983486431506&w=2
- BUGTRAQ:19990209 Re: IIS4 allows proxied password attacks over NetBIOS
- URL: http://marc.info/?l=bugtraq&m=92000623021036&w=2
- XF:iis-iisadmpwd