Exploitability Index – More Information for Customers

Yesterday at Black Hat 2008, along with some other stuff, we announced that we will be adding some new information to Security Bulletins – an “Exploitability Index” for each of the vulnerabilities addressed by the bulletin.

Based upon talking with Microsoft customers over the past five years, they are always looking for that little bit of extra information to help make prioritization decisions.  An obvious example of this is the severity attached to the vulns.  However, as explained by Mike Reavey of the the Microsoft Security Response Center (MSRC) over on the Ecostrat blog today, customers are also very interested in which vulnerabilities already have exploit code or sample exploits available.

According to our analysis in the most recent Security Intelligence Report (SIR), only about 30 percent of the vulnerabilities we fix each year have exploit code released.  Why is it not 100% ?  Some are not interesting to attackers, sure, but some are simply more challenging to develop a consistent exploit against.  It seems like it would be practically useful if this sort of information could be analyzed and published for customers.

How does one come up with an Exploitability Index?

  • The MSRC will analyze the vulnerability and explore what it would take to exploit it, with the support of our Security Vulnerability Research & Defense (SVRD) team.  This will include leveraging methodologies from the broad researcher community.
  • We will also ask security researcher members of the Microsoft Active Protections Program (MAPP) (download FAQ) to review the vulnerabilities and check our analysis before releasing the index.

The idea of the Exploitability Index is to provide more information to help customers prioritize Microsoft security updates. This Index will reflect our best estimate, scrutinized by MAPP partners, of the likelihood of a functional exploit being developed for a given vulnerability.

If you are interested, I did an interview with Mike Reavey a while back, where we discuss what sort of information customers want that isn’t yet in Security Bulletins.  FYI, the video is about 15 minutes long and the early part focuses on Mike, how he got into security and how he ended up at Microsoft before we get to the Security Bulletin discussion … if you want to get right to the Security Bulletin discussion, skip forward to about 08:40.

If you like these sorts of videos, click on
SecurityGuy 001 – Interview with MSRC Leader Mike Reavey and it’ll take you to the edge.technet.com site and you can check out the related videos.

Regards ~ Jeff

About the Author
Jeff Jones

Principal Cybersecurity Strategist

Jeff Jones a 27-year security industry professional that has spent the last decade at Microsoft working with enterprise CSOs and Microsoft's internal teams to drive practical and measurable security improvements into Microsoft products and services. Additionally, Jeff analyzes vulnerability trends Read more »