Five common mistakes in the web.config file
Коротко без описаний:
1. Custom Errors Disabled
customErrors mode="RemoteOnly"
2. Leaving Tracing Enabled in Web-Based Applications
trace enabled="false" localOnly="true"
3. Debugging Enabled
compilation debug="false"
4. Cookies Accessible through Client-Side Script
httpCookies httpOnlyCookies="true"
5. Cookieless Session State Enabled
sessionState cookieless="UseCookies"