The “Real World” of Developer-centric Security

My friend and colleague, Dr. James Ransome, invited me late last Winter to write a chapter for his 10th book on computer security, Core Software Security(with co-author, Anmol Misra published by CRC Press. My chapter is “The SDL In The Real World”, SDL = “Secure Development Lifecycle”. The book was released December 9, 2013. You can get copies from the usual sources (no adverts here, as always).

It was an exciting process. James and I spent hours white boarding possible SDL approaches, which was very fun, indeed*. We collectively challenged ourselves to uncover current SDL assumptions, poke at the validity of these, and find better approaches, if possible.

Many of you already know that I’ve been working towards a different approach to the very difficult, multi-dimensional and multi-variate problem of designing and implementing secure software for a rather long time. Some of my earlier work has been presented to the industry on a regular basis.

Specifically, during the period of 2007-9, I talked about a new (then) approach to security verification that would be easy for developers to integrate into their workflow and which wouldn’t require a deep understanding of security vulnerabilities nor of security testing. At the time, this approach was a radical departure.

The proving ground for these ideas was my program at Cisco, Baseline Application Vulnerability Assessment, or BAVA, for short (“my” here does not exclude the many people who contributed greatly to BAVA’s structure and success. But it was more or less my idea and I was the technical leader for the program).

But, is ease and simplicity all that’s necessary? By now, many vendors have jumped on the bandwagon; BAVA’s tenets are hardly even newsworthy at this point**. Still, the dream has not been realized, as far as I can see. Vulnerability scanning still suffers from a slew of impediments from a developer’s view:

  • Results count vulnerabilities not software errors
  • Results are noisy, often many variations of a single error are reported uniquely
  • Tools are hard to set up
  • Tools require considerable tool  knowledge and experience, too much for developers’ highly over-subscribed days
  • Qualification of results requires more in-depth security knowledge than even senior developers generally have (much less an average developer)

And that’s just the tool side of the problem. What about architecture and design? What about building security in during iterative, fast paced, and fast changing agile development practices? How about continuous integration?

As I was writing my chapter, something crystalized. I named it, “developer-centric security”, which then managed to get wrapped into the press release and marketing materials of the book. Think about this:  how does the security picture change if we re-shape what we do by taking the developer’s perspective rather than a security person’s?

Developer-centric software security then reduced to single, pointed question:

What am I doing to enable developers to innovate securely while they are designing and writing software?

Software development remains a creative and innovative activity. But so often, we on the security side try to put the brakes on innovation in favour of security. Policies, standards, etc., all try to set out the rules by which software should be produced. From an innovator’s view at least some of the time, developers are iterating through solutions to a new problem while searching for the best way to solve it. How might security folk enable that process? That’s the question I started to ask myself.

Enabling creativity, thinking like a developer, while integrating into her or his workflow is the essence of developer-centric security. Trust and verify. (I think we have to get rid of that old “but”)

Like all published works, the book represents a point-in-time. My thinking has accelerated since the chapter was completed. Write me if you’re intrigued, if you’d like more about developer-centric security.

Have a great day wherever you happen to be on this spinning orb we call home, Earth.



*Several of the intermediate diagrams boggle in complexity and their busy quality. Like much software development, we had to work iteratively. Intermediate ideas grew and shifted as we worked. a creative process?

**At the time, after hearing BAVA’s requirements, one vendor told me, “I’ll call you back next year.”. Six months later on a vendor webcast, that same vendor was extolling the very tenets that I’d given them earlier. Sea change?

RSA 2013 & Risk

Monday, February 25th, I had the opportunity to participate in the Risk Seminar at RSA 2013.

My co-presenters/panelists are pursuing a number of avenues to strengthen not only their own practices, but for all. As I believe, it turns out that plenty of us practitioners have come to understand just how difficult a risk practice is. We work with an absence of hard longitudinal data, with literally thousands of variant scenarios, generally assessing ambiguous situations. Is that hard enough?

Further complicating our picture and methods is the lack of precision when we discuss risk. We all think we know what we mean, but do we? Threats get “prioritized” into risks. Vulnerabilities, taken by themselves with no context whatsoever, are assigned “risk levels”. Vulnerability discovery tools ratings don’t help this discussion.

We all intuitively understand what risk is; we calculate risk every day. We also intuitively understand that risk has a threat component, a vulnerability component, vulnerabilities have to be exploited, threats must have have the capacity and access to exploit. There are mitigation strategies, and risk always involves some sort of  impact or loss. But expressing these relationships is difficult. We want to shorthand all that complexity into simple, easily digestible statements.

Each RSA attendee received a magazine filled with short articles culled from the publisher’s risk archives. Within the first sentences risk was equated to threat (not that the writer bothered to define “threat”), to vulnerability, to exploit. Our risk language is a jumble!

Still, we plod on, doing the best that we can with the tools at hand, mostly our experience, our ability to correlate and analyze, and any wisdom that we may have picked up along the journey.

Doug Graham from EMC is having some success through focusing on business risk (thus bypassing all those arguments about whether that Cross-site Scripting Vulnerability is really, really dangerous). He has developed risk owners throughout his sister organizations much as I’ve used an extended team of security architects successfully at a number of organizations.

Summer Fowler from Carnegie-Mellon reported on basic research being done on just how we make risk decisions and how we can make our decisions more successful and relevant.

All great stuff, I think.

And me? I presented the risk calculation methodology that Vinay Bansal and I developed at Cisco, based on previous, formative work by Catherine Blackadder Nelson and Rakesh Bharania. Hopefully, someday, the SANS Institute will be able to publish the Smart Guide that Vinay and I wrote describing the method?*

That method, named “Just Good Enough Risk Rating” (JGERR) is lightweight and repeatable process through which assessors can generate numbers that are comparable. That is one of the most difficult issues we face today; my risk rating is quite likely to be different than yours.

It’s difficult to get the assessor’s bias out of risk ratings. Part of that work, I would argue, should be done by every assessor. Instead of pretending that one can be completely rational (impossible and actually wrong-headed, since risk always involves value judgements), I call upon us all to do our personal homework by understanding our own, unique risk preferences. At least let your bias be conscious and understood.

Still, JGERR and similar methods (there are similar methods, good ones! I’m not selling anything here) help to isolate assessor bias and at the very least put some rigour into the assessment.

Thanks  to Jack Jones’ FAIR risk methodology, upon which JGERR is partly based, I believe that we can adopt a consistent risk lexicon, developing a more rigorous understand of the relationships between the various components that make up a risk calculation. Thanks, Jack. Sorry that I missed you; you were speaking at the same time that I was in the room next door to mine. Sigh.

As Chris Houlder, CISO of Autodesk, likes to say, “progress, not perfection”. Yeah, I think I see a few interesting paths to follow.



*In order to generate some demand, may I suggest that you contact SANS and tell them that you’d like the guide? The manuscript has been finished and reviewed for more than a year as of this post.

Alan Paller’s Security Architecture Call To Action

I was attending the 2nd SANS What Works in Security Architecture Summit, listening to Alan Paller, Director of Research at the SANS Institute, and Michele Guel, National Cybersecurity Award winner. Alan has given us all a call to action, namely, to build a collection of architectural solutions for security architecture practitioners. The body of work would be akin to Up To Date for medical clinicians.

I believe that creating these guides is one of the next critical steps for security architects as a profession. Why?

It’s my contention that most experienced practioners are carrying a bundle of solution patterns in their heads. Like a doctor, we can eyeball a system, view the right type of system diagram, get a few basic pieces of information, and then begin very quickly to assess which of those patterns may be applicable.

In assessing a system for security, of course, it is often like peeling an onion. More and more issues get uncovered as the details are uncovered. Still, I’ve watched experienced architects very quickly zero in to the most relevant questions. They’ve seen so many systems that they intuitively understand where to dig deeper in order to assess attack vectors and what is not important.

One of the reasons this can happen so quickly is almost entirely local to each practitioner’s environment. Architects must know their environments intimately. That local knowledge will eliminate irrelevant threats and attack patterns. Plus, the architect also knows  which  security controls are pre-existing in supporting systems. These controls have already been vetted.

Along with the local knowledge, the experienced practioner will have a sense of the organization’s risk posture and security goals. These will highlight not only threats and classes of vulnerabilities, but also the value of assets under consideration.

Less obvious, a good security architecture practitioner brings a set of practical solutions that are tested, tried, and true that can be applied to the  analysis.

As a discipline, I don’t think we’ve been particularly good at building a collective knowledge base. There is no extant body of solutions to which a practioner can turn. It’s strictly the “school of hard knocks”; one learns by doing, by making mistakes, by missing important pieces, by internalizing the local solution set, and hopefully, through peer review, if available.

But what happens when a lone practioner is confronted with a new situation or technology area with which he or she is unfamiliar? Without strong peer review and mentorship, to where does the architect turn?

Today, there is nothing at the right level.

One can research protocols, vendors, technical details. Once I’ve done my research, I usually have to infer the architectural patterns from these sources.

And, have you tried getting a vendor to convey a product’s architecture? Reviewing a vendor’s architecture is often frought with difficulties: salespeople usually don’t know, and sales engineers just want to make the product work, typically as a cookie cutter recipe. How many times have I heard, “but no other customer requires this!”

There just aren’t many documented architectural patterns available. And, of the little that is available, most has not been vetted for quality and proof.

Alan Paller is calling on us to set down our solutions. SANS’ new Smart Guide series was created for this purpose. These are intended to be short, concise security architecture solutions that can be understood quickly. These won’t be white papers nor the results of research. The solutions must demonstrate a proven track record.

There are two tasks that must be accomplished for the Smart Guide series to be successful.

  • Authors need to write down the architectures of their successes
  • The series will need reviewers to vet guides so that we can rely on the solutions

I think that the Smart Guides are one of the key steps that will help us all mature security architecture practice. From the current state of Art (often based upon personality) we will force ourselves to:

  • Be succinct
  • Be understandable to a broad range of readers and experience
  • Be methodical
  • Set down all the steps required to implement – especially considering local assumptions that may not be true for others
  • Eliminate excess

And, by vetting these guides for worthwhile content, we should begin to deliver more consistency in the practice. I also think that we may discover that there’s a good deal of consensus in what we do every day**. Smart Guides have to juried by a body of peers in order for us to trust the content.

It’s a Call to Action. Let’s build a respository of best practice. Are you willing to answer the call?



** Simply getting together with a fair sampling of people who do what I do makes me believe that there is a fair amount of consensus. But that’s entirely my anecdotal experience in the absence of any better data