May 16 2007
Reduced attack surface area
Jeff Jones (Strategy Director in the Microsoft Security Technology Unit) has written a post about Server Core and how its reduced footprint increases security dramatically. The key here is “reduced attack surface area” as all of the most insecure areas of a server have been removed, such as IIS, Internet Explorer, Windows Media Player, etc…
However, pulling all these components out of a server have also reduced its functionality, which is why only the following roles are available: (taken from the excellent Server Core Step By Step Guide)
- Active Directory Domain Services
- Active Directory Lightweight Directory Services (AD LDS)
- Dynamic Host Configuration Protocol (DHCP) Server
- DNS Server
- File Services
- Print Server
- Streaming Media Services
I’m a big fan of this approach and I can’t wait for Server Core to be improved so that the GUI is completely removed. I also hope that the modulisation of the components is improved so that the Web Server role becomes available as a Server Core option. It would seem to me that one of the best scenarios to implement a server with a “reduced attack surface area” would be on a public-facing web server.