IIS 4.0 allows local users to bypass the "User cannot change password" policy for Windows NT by directly calling .htr password changing programs in the /iisadmpwd directory, including (1) aexp2.htr, (2) aexp2b.htr, (3) aexp3.htr , or (4) aexp4.htr.
http://www.securityfocus.com/bid/4236