FileSystemObject (FSO) in the showfile.asp Active Server Page (ASP) allows remote attackers to read arbitrary files by specifying the name in the file parameter.
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.
A buffer overflow in the FTP list (ls) command in IIS allows remote attackers to conduct a denial of service and, in some cases, execute arbitrary commands.
The ExAir sample site in IIS 4 allows remote attackers to cause a denial of service (CPU consumption) via a direct request to the (1) advsearch.asp, (2) query.asp, or (3) search.asp scripts.
Buffer overflow in FTP server in Microsoft IIS 3.0 and 4.0 allows local and sometimes remote attackers to cause a denial of service via a long NLST (ls) command.
When IIS 2 or 3 is upgraded to IIS 4, ism.dll is inadvertently left in /scripts/iisadmin, which does not restrict access to the local machine and allows an unauthorized user to gain access to sensitive server information, including the Administrator's password.