Vulnerability (noun): A Word Vulnerable to Misuse

Jody Brazil

Vulnerability…I do not think it means what you think it means.

Continuing our series of posts on Risk, I wanted to next shine a light on one of the most misunderstood or better yet, misused terms in security, vulnerability.  What does vulnerability mean to you? How is it connected to Risk?

While vulnerability is certainly part of any risk analysis the term has been co-opted out of all proportion to most of the security and risk management space. This is partly due to the great job that the vulnerability management and patch management vendors have done in bringing vulnerabilities to the forefront of our risk management activities. But as we said in our earlier post, there is more to Risk than vulnerability.

Rather than reinvent the wheel I wanted to go back to what many consider a seminal piece on the subject. Jack Jones’s, An Introduction to Factor Analysis of Information Risk (FAIR). Jones perhaps said it best when he wrote,

A ?nal point is that there’s a tendency to equate vulnerability with risk.  We see a frayed rope (or a server that isn’t properly con?gured) and automatically conclude that the risk is high.  Is there a correlation between vulnerability and risk? Yes.  Is the correlation linear?  No, because vulnerability is only one component of risk.  Threat event frequency and loss magnitude also are key parts of the risk equation.

So, in spite of this, why have so many gone off the deep end on vulnerabilities? I imagine it is due to highly publicized and severe vulnerabilities that keep being disclosed on a frequent and regular basis along with the fact that it is the best measured factor in security today (see CVSS).  Using a baseball analogy from Moneyball, measuring vulnerabilities to infer risk out of context from threats, other security countermeasures, and other risk factors is similar to tracking the stat at bats as a key metric to measure wins.  Related, yes.  Direct correlation, no. Just because there is a vulnerability doesn’t mean it will be exploited, that it can be reached and it is worth exploiting. So in measuring risk, it is critical to measure more than just vulnerabilities.

I am not suggesting we stop assessing and measuring vulnerabilities.  However, with risk based products like our Risk Analyzer, I hope we start including some of the other factors that need to be included in our analysis so that we can start measuring risk more completely.

Vulnerability is not Risk.  Inconceivable!