The Futility Of Security By Obscurity

Last week saw the launch of Shodan, a search engine for machines (servers, routers, etc.) connected to the Internet.Shodan, which was created by John Matherly, comes with a Google-like interface that lets you query to find servers that have certain characteristics; finally, the futility of security by obscurity can now be demonstrated easily by anybody with access to a browser. One can search for strings, anything really, but in general by applications, IP address, or domain name, and further filter by ports (i.e. port:80), location (country:DE), and name (hostname:thor.)

Here are a number of sample Shodan queries:
- How many servers in the US: http://shodan.surtri.com/?q=country:US
  Result: 2667688
- How many servers with telnet in the U.S.: http://shodan.surtri.com/?q=country:US+port:23
  Result: 2500
- Who runs IIS 4.0 in the US: http://shodan.surtri.com/?q=iis+4.0+country:US
  Result: 1824
- Wordpress login: http://shodan.surtri.com/?q=wordpress+wp-login.php
  Result: 5 - Very timely, as there was news today on distributed WordPress login brute-forcing.

This is a great service, and I hope John can expand on the underlying database. There has already been some controversy as to whether this (public?) information should be made so accessible. For me, the positive effects outweigh the negatives: The information is now accessible to everybody -- and not only to experienced attackers who have without doubt invested already time and resources into similar maps.

Follow John on Twitter for updates to the service: twitter.com/achillean

-- As the CTO for Qualys, Wolfgang Kandek is responsible for product direction and all operational aspects of the QualysGuard platform and its infrastructure. Wolfgang has more than 20 years of experience in developing and managing information systems. His focus has been on Unix-based server architectures and application delivery through the Internet. Wolfgang provides the latest commentary on his blog: laws.qualys.com and also publishes his Patch Tuesday commentary to the QualysGuard channel: http://www.youtube.com/QualysGuard. He is a frequent source in business and trade media and speaks at industry conferences around the world, most recently at RSA 2009.