Hole affects all versions of the .Net framework when used on Windows Server operating systems. Desktop systems are not vulnerable unless they are being used to run a Web server.
Microsoft offers workaround and prepares patch after researchers reveal hole in ASP.Net software used in millions of Web sites.
Advisory helps Web sites that use Microsoft ASP and ASP.NET technologies against recent Web-based attacks.
The software giant woos hosting firms away from open source with support for SQL Server 2005 and ASP.Net 2.0.