Steve Riley on Security

Formerly of Microsoft's Trustworthy Computing Group.

Who should do your security audits? Or, how do you organize the security department?

Who should do your security audits? Or, how do you organize the security department?

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An interesting question came up today. The group responsible for configuring and maintaining the firewalls at a customer also believes that they should be the only ones to audit their configurations. Others in the security department are uneasy with this, and prefer that someone else do the auditing. I've encountered similar tension before, and it always makes me wonder why information security folk and auditors frequently have trouble working together. As I thought more about this, I began to wonder if maybe there's a better way to organize the entire security department.

It's useful if we take a moment and consider the definition of the auditing function. Here's mine:

Audits help us ensure that we are following our own policies. Audits measure the current state, compare the results against what the state should be, and show where we are out of compliance. Essentially, audits help us know that we are indeed doing what we say we're doing.

Audits are the natural outcomes of implementing good policies and following effective procedures. It makes no sense to spend time developing policies and without having some mechanism to measure compliance. That's the role of the auditing function -- to measure compliance. If we all agree that policies are good, then we should all agree that checking up on ourselves is also good.

So, then, who should conduct the audits? For comparison, let's examine a typical software development department. Here at Microsoft, such departments are composed of four over-arching roles:

  • program management
  • product management
  • software development
  • software test

Why this way? Consider the first two. We don't have "project managers" at Microsoft because project management incorporates two conflicting goals: managing people, schedules, and budgets (program management) versus incorporating customer requirements and creating new markets (product management). Program management optimizes resources while product management optimizes features. Rather than shoulder that inherent conflict onto a single person and expect them to deal with it without going completely bonkers, we have two roles, with different people. People skilled in each area negotiate with each other and come to an agreement about what's best both for Microsoft and for our customers.

Similar thinking exists for the second pair of roles. Developers strive to write high-quality code, and even do some testing along the way. But because no one's perfect, all code has some mistakes; it's valuable to have other people bang hard on the code, abuse it almost, to find and squash more bugs. Often, even the best developers are embedded so deeply in their own code that some bugs escape them. Developers rightly concern themselves with creating code that works and provides proper output. Testers figure out how to purposefully break software and discover code vulnerabilities. These are different skill sets, and using different people results in higher quality software.

We can apply the same logic to the information security department. How about these four roles:

  • security standards
  • security alignment
  • security operations
  • security auditing

The security standards group defines an organization's security architecture, creates policies and procedures, and ultimately takes responsibility for stewarding the integrity of the organization's information assets. The security alignment group spends time understanding the needs and drivers of the various business units, and advocates the business units' positions in meetings with the security standards group. Like in the software development model, having different folks negotiate together about standards and alignment helps ensure that business needs are met while also ensuring that the business is able to rely on information that's kept secure.

Remember: the primary purpose of information security is risk management. The standards folk know all about the bad guys and their techniques, and build up knowledge about which threats create risk for the organization. The alignment folk understand, through their constant interaction with people in the business units, all about business risk and get a feel for the business's risk tolerance -- that is, the level and kinds of risk that matter or don't matter. Together, the security standards and the security alignment folk can develop a security posture that allows the business to remain agile while also addressing the risks that make sense.

(Notice that I haven't indicated where, exactly, the alignment folk sit within the organization. They might be part of the security department, or they might be part of the individual business units. A case could be made for either choice; however, except for very large organizations, the alignment role probably isn't full-time. This leans the role toward sitting in the business units.)

Day-to-day work becomes the responsibility of those in security operations. They create standard configurations, perform installs and updates, monitor traffic, and respond to incidents. Ideally, policies and procedures guide all of these activities. But having policies and procedures isn't enough: we must also have a way to measure conformance. And that's the role of security auditing. Security auditors compare a system's current configuration to what it should be, based on the policy. Where systems are out of compliance, the auditor works with operations folk to understand the reasons, without engaging in blame-storming or launching personal attacks (this goes for operations folk, too). Most of the time, it's simply a mistake; here, auditors are like software testers, uncovering configuration vulnerabilities (bugs) that otherwise might be overlooked by operations and thus exploited by attackers.

Now you auditors out there, this doesn't mean that your role is simply that of checklist slave. Especially if your checklist is something you downloaded from the Internet. Remember: these checklists are only guidance, good ideas written by a person (or a committee) based on that person's risk tolerance. Effective auditors develop relationships with people in the other three groups: standards, alignment, and operations. Effective auditors take the time to learn the security landscape, how attackers operate, where vulnerabilities lie, and which threats matter. Really effective auditors learn how to do penetration testing, thus uncovering not only code and configuration vulnerabilities but also circumvention vulnerabilities through social engineering. By doing this, effective auditors remove the "us versus them" stigma often associated with auditing and truly become part of the security team, all working together to protect the organization's information assets.

(Notice that, as with the alignment group, I haven't indicated organizationally where the audit group should sit. I do, however, have a strong opinion on this: the management chains of the audit group and the operations group must be different. The people conducting audits shouldn't work for those who have a stake in an audit's outcome. To do so would create unavoidable and unrecoverable conflicts of interest.)

I'm sure there's more to the topic of organizing a security department. What do you think of this approach? Do you like the idea of dividing conflicting roles into different groups, then structuring them to work together to achieve realistic and useful outcomes? I don't suspect I've necessarily invented anything new here, but maybe just used a few new words -- such as "security alignment" -- and thought out loud about some of the tension that exists within the standards/alignment and operations/audit pairs. (Oh, and I got to write about my code/configuration/circumvention vulnerability triple again, heh.) Please tell me your thoughts. Maybe there's an entire white paper here, possibly even a TechEd presentation. Maybe someday we should offer a "TechManagementEd" conference!

Comments
  • Hi Steve,

    The security standards group defines an organization’s security architecture and they will only be able to do it when they will understand the needs and drivers of the various business units. So, there shouldn’t be conflict between standards/alignment roles or you can say both roles are similar.

    I agree and liked your explanation on operations/auditing though….But, if auditors perform their task as you have defined then there will be no conflict in these two roles either…

    According to me it should be like this:

    Security Risk Management

    Security Alignment / standards

    Security Operations

    Security Auditing

    The reason why I have put standards after alignment is after understanding the needs and drivers of the various business units through risk management they will be able to work on standards which will later help security operations. In the end good auditing can help to ensure all policies are used appropriately.

    Cheers

    Shoaib

  • Thank You For Sharin very inforamtive materials with us

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