IIS 6.0 makes URLScan almost obsolete
Security minded IIS administrators are aware of URLScan as a staple of IIS 5.0 and IIS 4.0 security. This Internet Server API (ISAPI) filter lets you configure your server to quickly reject client requests that don't meet criteria you define in the urlscan.ini file. IIS 6.0 has many significant security improvements, which is one reason I frequently hear the question "Do I need to run URLScan with IIS 6.0?"
The general answer to this question is "probably not." Of course, that's not a very satisfying answer, so let's see if I can help clarify things for your particular circumstances by mapping URLScan features to IIS 6 features.
[ Read more ]