Windows Authentication Mode is the default and recommended authentication mode. It tactfully leverages Active Directory user accounts or groups when granting access to SQL Server.

We’ll use Windows Authentication Mode as opposed to SQL Server Mixed Mode. (Mixed Mode comprises Windows Security and SQL Server’s own security model.

If you are using mixed authentication mode (“SQL Server & Windows Authentication Mode”) you are vulnerable. SQL Server 2000, 2005, and 2008, running on all supported Windows platforms.

This feature, known as Extended Protection for Authentication (Extended Protection, for short), helps secure connections to a SQL Server 2008 R2 server.