Sunday, June 21, 2009

Offense and Defense Inform Each Other

If you've listened to anyone talking about the Top 20 list called the Consensus Audit Guidelines recently, you've probably heard the phrase "offense informing defense." In other words, talk to your Red Team / penetration testers to learn how they can compromise your enterprise in order to better defend yourself from real adversaries.

I think this is a great idea, but there isn't anything revolutionary about it. It's really just one step above the previous pervasive mindset for digital security, namely identifying vulnerabilities. In fact, this neatly maps into my Digital Situational Awareness ranking. However, if you spend most of your time writing policy and legal documents, and not really having to deal with intrusions, this idea probably looks like a bolt of lightning!

And speaking of the Consensus Audit Guidelines: hey CAG! It's the year 2000 and the SANS Top 20 List wants to talk to you!

The SANS/FBI Top Twenty list is valuable because the majority of successful attacks on computer systems via the Internet can be traced to exploitation of security flaws on this list...

In the past, system administrators reported that they had not corrected many of these flaws because they simply did not know which vulnerabilities were most dangerous, and they were too busy to correct them all...

The Top Twenty list is designed to help alleviate that problem by combining the knowledge of dozens of leading security experts from the most security-conscious federal agencies, the leading security software vendors and consulting firms, the top university-based security programs, and CERT/CC and the SANS Institute.


Expect at some point to hear Beltway Bandits talking about how we need to move beyond talking to the Red Team and how we need to see who is actively exploiting us. Guess what -- that's where the detection and response team lives. Perhaps at some point these "thought leaders" will figure out the best way to defend the enterprise is through counterintelligence operations, like the police use against organized crime?

For now, I wanted to depict that while it is indeed important for offense to inform defense, the opposite is just as critical. After all, how is the Red Team supposed to simulate the adversary if it doesn't know how the adversary operates? A good Red Team can exploit a target using methods known to the Red Team. A great Red Team can exploit a target using methods known to the adversary. Therefore, I created an image describing how offense and defense inform each other. This assumes a sufficiently mature, resourced, and capable set of security teams.



This post may sound sarcastic but I'm not really bitter about the situation. If we keep making progress like this, in 3-5 years the mindset of the information security community will have evolved to where it needed to be ten years ago. I'll keep my eye on the Beltway Bandits to let you know how things proceed.


Richard Bejtlich is teaching new classes in Las Vegas in 2009. Regular Las Vegas registration ends 1 July.

1 comment:

CG said...

the important thing that red teaming/full scope pentesting can do in addition to all the things you mentioned is seeing if you network is set up where one vulnerability owns your whole network. I also like to stress the detect and respond piece. do you detect the bad guy moving around your network, or see that data egressing the border, those types of things arent going to be looked at or found with your nessus scan.