The version of ASP.NET is sent in a banner with http requests and can be viewed with a curl command. I’ll show you how!
To view this with curl, use tack capital I and fetch any url ending in .aspx. A random url ending in .aspx works as well:
$ curl -I 10.112.12.67/asdfsaf.aspx HTTP/1.1 404 Not Found Cache-Control: private Content-Length: 1507 Content-Type: text/html; charset=utf-8 Server: Microsoft-IIS/7.5 X-AspNet-Version: 2.0.50727 X-Powered-By: ASP.NET Date: Fri, 11 May 2012 13:13:50 GMT
Note that ASP.NET 2.x – 3.5 all reflect the same banner. The above example is running ASP.NET 3.5.1.