DevSecCon London 2017

BugsAh, London — the city responsible for most of my music collection. Also, the city where I recently had the fortune to present at DevSecCon.

DevSecCon examines the challenges facing DevSecOps (and DevOps) practitioners. It emphasizes how to work with people to make tools and process part of the CI/CD pipeline. This resonates with me greatly because I strongly believe that effective security comes from participation and empathy.

DevSecOps brings security teams into the difficult tasks of writing, supporting, and maintaining code. It’s a welcome departure from delivering a “Go fix this” message. Sometimes developers need guidance on basic security principles and an introduction to the OWASP Top 10. Sometimes developers have that knowledge and are making tough engineering choices between conflicting recommendations. Security shouldn’t be the party that says, “No”. Their response should be, “Here’s a way to do that more securely.”

The “Go fix this” attitude has underserved appsec. We live in an age of 130,000+ Unicode characters and extensive emoji. Yet developers must still (for the most part) handle apostrophes and angle brackets as special exceptions lest their code suffer from HTML injection, cross-site scripting, or a range of other injection-based flaws.

All this is to say, check out my presentation, which explores this from the perspective of vuln discovery — and that too much investment in vuln discovery at the time when an app reaches production misses the chance to build stronger foundations.


DevOps Is Automation, DevSecOps Is People

A lot of appsec boils down to DevOps ideals like feedback loops, automation, and flexibility to respond to situations quickly. DevOps has the principles to support security, it should have to knowledge and tools to apply it.

Real-world appsec deals with constraints like time, budget, and resources. Navigating these trade-offs requires building skills in collaboration and informed decision-making. On the technology side, we have containers, top 10 lists, and tools. Whether we’re focused on more efficient meetings or trying to driving change across an organization, we need equal attention on techniques that make the social aspects of security successful.

We build automation with apps. We build relationships with people. This presentation explores methods for establishing incentives, encouraging participation, providing constructive feedback, and reaching goals as a team. It shows different ways to use metrics and communication to drive positive behaviors. These are important skills not only for managing teams, but for influencing appsec among peers and growing a career.

Security is an integral part of DevOps. And, yes, it’s made of people.

Here’s a new abstract to seed content for the blog and for conference talks. I’ve alluded to people before, where they are the target of consumption. Now I’d like to look at people as both the audience to benefit from appsec as well as the collaborators for improving it.

Stay tuned for more!

ISC2 Security Congress, 4416 – GBU Slides

RattlesnakeMy presentation on the good, the bad, and the ugly about crowdsourced security continues to evolve. The title, of course, references Sergio Leone’s epic western. But the presentation isn’t a lazy metaphor based on a few words of the movie. The movie is far richer than that, showing conflicting motivations and shifting alliances.

The presentation is about building alliances, especially when you’re working with crowds of uncertain trust or motivations that don’t fully align with yours. It shows how to define metrics and use them to guide decisions.

Ultimately, it’s about reducing risk. Just chasing bugs isn’t a security strategy. Nor is waiting for an enumeration of vulns in production a security exercise. Reducing risk requires making the effort to understand what what you’re trying to protect, measuring how that risk changes over time, and choosing where to invest to be most effective at lowering that risk. A lot of this boils down to DevOps ideals like feedback loops, automation, and flexibility to respond to situations quickly. DevOps has the principles to support security, it should have to knowledge and tools to apply it.

Now One Week All Year

The annual summer conference constellation of the week of Black Hat, BSides, and DEF CON usually brings out a certain vocal concern about personal device security. Some of the concern is grounded in wry humor, using mirth to illustrate a point. Some of it floats on ignorance tainted with misapplied knowledge. That’s fine. Perform the rituals and incantations that make you feel better. Enjoy the conferences, have fun, share some knowledge, learn some skills.

But after you select a level of extra precaution. Ask why such a choice is necessary for one week of the year. It’s a question without a single answer. As a leading question, it’s intended to elicit reasons based on a coherent threat model that addresses the week’s anticipated behaviors and environments. As an antagonistic question, it’s intended to explore why “default secure” is insufficient or why, after more than two decades of one-week-a-year concern, system and device security is so poor that none of it can be trusted outside your home network.

As you ponder an answer, take a moment to help someone else improve their baseline security profile.

  • For a mobile device, set a passcode longer than four characters.
  • For a mobile device, enable Touch ID or similar biometric feature.
  • Turn on automatic updates.
  • Enable multi-factor authentication (MFA, 2FA, Security Key, App Authenticator, or whatever synonym it supports) for their email, social media, and financial accounts.
  • Record and save recovery codes associated with enabling MFA. Help them choose an effective storage, such as printed and placed somewhere safe or in a password-protected keychain.

As a follow-up to enabling MFA, help them update and make unique each of their passwords.

  • Install a password manager.
  • Starting with their most-used sites, go through the password change process and allow the password manager to assign a new, unique password. If they wish to have a memorable password, ensure that it’s only used for that account.
  • Review any OAuth or Social Logins used for the account, e.g. if they use Facebook, Twitter, LinkedIn, or similar to authenticate to the site or to allow access to their social account.

Now consider that there are people whose security precautions require attention 52 weeks of the year. People who have expressed an opinion. People who are women. People in abusive relationships. People without political representation, let alone power. These are different situations that need different approaches to securing devices and data.

These are people who can’t buy a “burner phone” for one week, then return to normal. Their normal isn’t the vague threat of a hostile network. It’s the direct threat from hostile actors — those with physical access to their devices, or maybe just knowledge of their passwords, or possibly just knowledge of their existence. But in each case an actor or actors who desire to obtain access to their identity, data, and accounts.

After helping someone with the basic security hygiene of setting strong passwords and turning on automatic updates, gather resources for how to deal with different threat models and different levels of concern. Help them translate those concerns into ways of protecting accounts and data.

One resource to start with could be

There’s a trope in infosec that this week has “the most hostile network” ever. A network may indeed be hostile, but a hostile playground network is far different from the threats against a network people use on a daily basis.

It can be fun as well as a great educational experience to attack a playground network. On the other hand, networks that no one can use or be expected to use aren’t reflective of security engineering. If you think a network can never be secured or a device never be safe, then you’ve possibly skipped over the exercise of threat modeling and making choices based on risk.

RVAsec 2017: Managing Crowdsourced Security Testing

This June at RVAsec 2017 I continued the discussion of metrics that reflect the effort spent on vuln discovery via crowdsourced models. It analyzes data from real-world bounty programs and pen tests in order to measure how time and money might both be invested wisely in finding vulns. Here are the slides for my presentation.

We shouldn’t chase an eternal BugOps strategy where an app’s security relies solely on fixing vulns found in production. We should be using vuln discovery as a feedback mechanism for improving DevOps processes and striving to automate ways to detect or prevent the flaws that manual analysis reveals.

And when we must turn to manual analysis, we should understand the metrics that help determine when it’s efficient, effective, and contributing to better appsec. This way we can being to model successful approaches within constrained budgets.


OWASP AppSec EU 2017 Presentation

FireHere are the slides for my presentation at OWASP AppSec EU this year: The Flaws in Hordes, the Security in Crowds. It’s an exploration of data from bug bounty programs and pen tests that offers ways to evaluate when a vuln discovery strategy is efficient or cost-effective.

OWASP records the sessions. I’ll post an update once video is available. In the meantime, you check out some background articles on my other blog and keep an eye out here for more content that expands on the concepts in the presentation.

Crowdsourced Security — The Good, the Bad, and the Ugly

In Sergio Leone’s epic three-hour western, The Good, the Bad, and the Ugly, the three main characters form shifting, uneasy alliances as they search for a cache of stolen gold. To quote Blondie (the Good), “Two hundred thousand dollars is a lot of money. We’re gonna’ have to earn it.”

Bug bounties have a lot of money. But you’re gonna’ have to earn it.

And if you’re running a bounty program you’re gonna’ have to spend it.


As appsec practitioners, our goal is to find vulns so we can fix them. We might share the same goal, just like those gunslingers, but we all have different motivations and different ways of getting there.

We also have different ways of discovering vulns, from code reviews to code scanners to web scanners to pen tests to bounty programs. If we’re allocating a budget for detecting, preventing, and responding to vulns, we need some way of determining what each share should be. That’s just as challenging as figuring out how to split a cache of gold three ways.

My presentation at Source Boston continues a discussion about how to evaluate whether a vuln discovery methodology is cost-effective and time-efficient. It covers metrics like the noise associated with unfiltered bug reports, strategies for reducing noise, keeping security testing in rhythm with DevOps efforts, and building collaborative alliances in order to ultimately reduce risk in an app.

Eternally chasing bugs isn’t a security strategy. But we can use bugs as feedback loops to improve our DevOps processes to detect vulns earlier, make them harder to introduce, and minimize their impact on production apps.

The American West is rife with mythology, and Sergio Leone’s films embrace it. Mythology gives us grand stories, sometimes it gives us insight into the quote-unquote, human condition. Other times it merely entertains or serves as a time capsule of well-intentioned, but terribly incorrect, thought.

With metrics, we can examine particular infosec mythologies and our understanding or appreciation of them.

With metrics, we can select and build different types of crowds, whether we’re aiming for a fistful of high-impact vulns from pen testing or merely plan to pay bounties for a few dollars more.

After all, appsec budgets are a lot of money, you’re gonna’ have to earn it.

Builder, Breaker, Blather, Why.

BuilderI recently gave a brief talk that noted how Let’s Encrypt and cloud-based architectures encourage positive appsec behaviors. Check out the slides and this blog post for a sense of the main points. Shortly thereafter a slew of security and stability events related to HTTPS and cloud services (SHA-1, Cloudbleed, S3 outage) seemed to undercut this thesis. But perhaps only superficially so. Rather than glibly dismiss these points, let’s examine these events from the perspective of risk and engineering — in other words, how complex systems and software are designed and respond to feedback loops.

This post is a stroll through HTTPS and cloud services, following a path of questions and ideas that builders and breakers might use to evaluate security; leaving the blather of empty pronouncements behind. It’s about the importance of critical thinking and seeking the reasons why a decision comes about.

Eventually Encrypted

For more than a decade at least two major hurdles have blocked pervasive HTTPS: Certs and configuration. The first was (and remains) convincing sites to deploy HTTPS at all, tightly coupled with making deployment HTTPS-only instead of mixed with unencrypted HTTP. The second is getting HTTPS deployments to use strong TLS configurations, e.g. TLS 1.2 with default ciphers that support forward secrecy.

For apps that handle credit cards, PCI has been a crucial driver for adopting strong HTTPS. Having a requirement to use transport encryption, backed by financial consequences for failure, has been more successful than either asking nicely, raising awareness at security conferences, or shaming. As a consequence, I suspect the rate of HTTPS adoption has been far faster for in-scope PCI sites than others.

The SSL Labs project could also be a factor in HTTPS adoption. It distilled a comprehensive analysis of a site’s TLS configuration into a simple letter score. The publically-visible results could be used as a shaming tactic, but that’s a weaker strategy for motivating positive change. The failure of shaming, especially as it relates to HTTPS, is partly demonstrated by the too-typical disregard of browser security warnings. (Which is itself a design challenge, not a user failure.)

Importantly, SSL Labs provides an easy way for organizations to consistently monitor and evaluate their sites. This is a step towards providing help for migration to HTTPS-only sites. App owners still bear the burden of fixing errors and misconfigurations, but this tool made it easier to measure and track their progress towards strong TLS.

Effectively Encrypted

Where SSL Labs inspires behavioral change via metrics, the Let’s Encrypt project empowers behavioral change by addressing fundamental challenges faced by app owners.

Let’s Encrypt eases the resource burden of managing HTTPS endpoints. It removes the initial cost of certs (they’re free!) and reduces the ongoing maintenance cost of deploying, rotating, and handling certs by supporting automation with the ACME protocol. Even so, solving the TLS cert problem is orthogonal to solving the TLS configuration problem. A valid Let’s Encrypt cert might still be deployed to an HTTPS service that gets a bad grade from SSL Labs.

A cert signed with SHA-1, for example, will lower its SSL Labs grade. SHA-1 has been known weak for years and discouraged from use, specifically for digital signatures. Having certs that are both free and easy to rotate (i.e. easy to obtain and deploy new ones) makes it easier for sites to migrate off deprecated versions. The ability to react quickly to change, whether security-related or not, is a sign of a mature organization. Automation as made possible via Let’s Encrypt is a great way to improve that ability.

BreakerThe recent work that demonstrated a SHA-1 collision is commendable, but it shouldn’t be the sudden reason you decided to stop using it. If such proof of danger is your sole deciding factor, you shouldn’t be using (or supporting) Flash or most Android phones.

Facebook explained their trade-offs along the way to hardening their TLS configuration and deprecating SHA-1. It was an engineering-driven security decision that evaluated solutions and chose among conflicting optimizations — all informed by measures of risk. Engineering is the key word in this paragraph; it’s how systems get built. Writing down a simple requirement and prototyping something on a single system with a few dozen users is far removed from delivering a service to hundreds of millions of people. WhatsApp’s crypto design fell into a similar discussion of risk-based engineering. Another example of evaluating risk and threat models is this excellent article on messaging app security and privacy.

Exceptional Events

Companies like Cloudflare take a step beyond SSL Labs and Let’s Encrypt by offering a service to handle both certs and configuration for sites. They pioneered techniques like Keyless SSL  in response to their distinctive threat model of handling private keys for multiple entities.

If you look at the Cloudbleed report and immediately think a service like that should be ditched, it’s important to question the reasoning behind such a risk assessment. Rather than make organizations suffer through the burden of building and maintaining HTTPS, they can have a service the establishes a strong default. Adoption of HTTPS is slow enough, and fraught with error, that services like this make sense for many site owners.

Compare this with heartbleed, which also affected TLS sites, could be more targeted, and exposed private keys (among other sensitive data). The cleanup was long, laborious, and haphazard. Cloudbleed had significant potential exposure, although its discovery and remediation likely led to a lower realized risk than heartbleed.

If you’re saying move away from services like that, what in practice are you saying to move towards? Self-hosted systems in a rack in an electrical closet? Systems that will likely degrade over time and, even more likely, never be upgraded to TLS 1.3? That seems ill-advised.Blather

Does the recent Amazon S3 outage raise concern for cloud-based systems? Not to a great degree. Or, at least, not in a new way. If your site was negatively impacted by the downtime, a good use of that time might have been exploring ways to architect fail-over systems or revisit failure modes and service degradation decisions. Sometimes it’s fine to explicitly accept certain failure modes. That’s what engineering and business do against constraints of resource and budget.

Coherently Considered

So, let’s leave a few exercises for the reader, a few open-ended questions on threat modeling and engineering.

Flash has been long rebuked as both a performance hog and security weakness. Like SHA-1, the infosec community has voiced this warning for years. There have even been one or two (maybe more) demonstrated exploits against it. It persists. It’s embedded in Chrome, which you can interpret as a paternalistic effort to sandbox it or (more cynically) an effort to ensure YouTube videos and ad revenue aren’t impacted by an exodus from the plugin — or perhaps somewhere in between.

Browsers have had impactful vulns, many of which carry significant risk and impact as measured by the annual $50K+ rewards from Pwn2Own competitions. The minuscule number of browser vendors carries risk beyond just vulns, affecting influence on standards and protections for privacy. Yet more browsers doesn’t necessarily equate to better security models within browsers.

On the topic of decentralization, how much is good, how much is bad? DNS recommendations go back and forth. We’ve seen huge DDoS against providers, taking out swaths of sites. We’ll see more. But is shifting DNS the right solution, or a matter that misses the underlying threat or cause of such attacks? How much of IoT is new or different (scale?) compared to the swarms of SQL Slammer and Windows XP botnets of yesteryear’s smaller internet population?

Approaching these with ideas around resilience, isolation, authn/authz models, or feedback loops are (just a few) traits of a builder. As much as they might be for a breaker executing attack models against them.

Approaching these by explaining design flaws and identifying implementation errors are (just a few) traits of a breaker. As much as they might be for a builder designing controls and barriers to disrupt attacks against them.

Approaching these by dismissing complexity, designing systems no one would (or could) use, or highlighting irrelevant flaws is often just blather. Infosec has its share of vacuous or overly-ambiguous phrases like military-grade encryption, perfectly secure, artificial intelligence (yeah, I know, blah blah blah Skynet), use-Tor-use-Signal. There’s a place for mockery and snark. This isn’t concern trolling, which is preoccupied with how things are said. This is about the understanding behind what is said — the risk calculation, the threat model, the constraints.

Constructive Closing

PourI believe in supporting people to self-identity along the spectrum of builder and breaker rather than pin them to narrow roles. (A principle applicable to many more important subjects as well.) This about the intellectual reward of tackling challenges faced by builders and breakers alike, and leaving behind the blather of uninformed opinions and empty solutions.

I’ll close with this observation from Carl Sagan (from his book, The Demon-Haunted World): “It is far better to grasp the universe as it really is than to persist in delusion, however satisfying and reassuring.”

Our application universe consists of systems and data and users, each in different orbits. Security should contribute to the gravity that binds them together, not the black hole that tears them apart. Engineering sees the universe as it really is; shed the delusion that one appsec solution in a vacuum is always universal.

An Event Mutates

This week I spoke again about evolving a bug bounty program. It was an iteration on A Mutation Event that I presented last month. In the spirit of my evolutionary metaphor, the content has been modified in its descent and adapted to the audience. The tweaks are both in presentation flow and in response to questions.

bugI’ve also called out more clearly that in security, crowds require more time to manage than you think and effective crowds are smaller than you think. Adding the qualifier “effective” shrinks the size from a crowd to a coterie.

Check out the updated slides. And know that the future will not only bring more evolution on this topic, but expansion into others.

A Mutation Event

The last time I was fortunate enough to present at a conference was a year ago at SOURCE Seattle. So it feels good to have had the chance to return in 2016 and present on a new topic of crowdsourced security.bug

The title was Evolving a Bug Bounty Program and, accordingly, it embraced a theme of descent with modification. In this case, building feedback loops and iterative processes based on various signals (and noise!) from of a bug bounty program.

You can hear a preview of some of the ideas in the Brakeing Security podcast that covered the conference. Enjoy!