Software Security: Building Security In

As it stands in many organizations, software security is nobody's job. Developers, architects, and other builders are often unaware of security and possess little in the way of software security knowledge. When their software suffers from security failure, they don't often feel responsible, arguing that security is up to the people in operations who install and operate the software they create.

A very common reaction among developers and software teams when confronted with a security problem in their system (say, during the presentation of risk analysis results) is "You can't do that! Nobody would ever do that! And even if they did, you're not supposed to do that!" Those software people who say things like that usually believe that security is IT's job and an infrastructure issue. By now you should know why that is incorrect. One key goal of the software security touchpoints is to arm software teams with enough information that these excuses never crop up. By understanding and thinking about security throughout the software development lifecycle, developers can avoid nasty surprises.

Operations people become upset when their pristine, mostly secure network is sullied by insecure software. They don't understand why software people produce such "crap," and they don't feel responsible for the ensuing security mess. They decry the pathetic state of software and wish that software developers knew more about security. In desperation, operations people grasp at security straws such as application firewalls and intrusion detection systems.

Obviously, this is not a healthy situation. When a security problem happens because of bad software, there really is nobody to hold responsible. The standard security people in operations are not really at fault (it's not their broken software), and neither are the software people (they're not security people). Organizationally, this is a textbook management problem.

In the best possible world, software security would be everybody's job. In a more realistic world, assigning responsibility and accountability to a particular group can help solve the problem.

One suggestion worth thinking about involves finding the person with the best handle on the way your whole software system works and tapping that person for software security. Ask who you turn to when something goes drastically wrong, but you don't have a clue about what is causing the problem. The jack-of-all-trades whom you turn to is your new software security person.[5]

[5] This is way too glib, of course (though it will appeal to those "builders" who are accustomed to the hero approach"we threw a guy at that"). More mature organizations need a better-fleshed-out "who," "what," "where" framework. Different people accept different portions of the responsibility as you divide, conquer, and collaborate. See Chapter 10.

Building a Software Security Group

The world has not yet produced many software security people. That's a shame because the world certainly needs more. Fortunately, academia appears to be slowly rising to the occasion, and a number of schools are beginning to teach software security and/or security engineering courses (see the next box, Software Security in the Academy).

There is not enough time to wait for academia to produce the solution. Instead, software security people need to be developed inside existing organizations (like yours). If you want to invent some software security people in your organization, consider the following advice.

Don't start with security people

Though software security is certainly essential to addressing the computer security fiasco we find ourselves in, a standard reactive approach will fail. Network security people often don't know enough about software to make good software security people. They may know loads of stuff about how software operations work (even more in many cases than developers and architects know), but this is not what we need to solve the software security problem. Normal security practitioners almost never know anything about compilers, language frameworks, software architecture, testing, and the myriad other things necessary to be a solid software person.

Software Security in the Academy

A number of academic institutions now offer security courses very much relevant to Building Security In. The best include the following:

  • University of California at Davis

  • University of Virginia

  • Johns Hopkins University

  • Princeton University

  • Purdue University (especially the CERIAS center)

  • Rice University

  • University of California at Berkeley

  • Stanford University

  • Naval Postgraduate School (a military school for graduates)

  • University of Idaho

  • Iowa State University

  • George Washington University

  • United States Military Academy at West Point

Just to highlight a couple of examples, here are some of the courses offered by these schools:

  • Introduction to Computer Security (practice): UC Davis

  • Computer and Information Security (theory): UC Davis

  • Computer Security: An Intrusion Detection Approach: UC Davis

  • Foundations of Computer and Information Security: UC Davis

  • Computer Incident Detection and Response: Purdue

  • Cryptography and Data Security: Purdue

  • Penetration Analysis: Purdue

  • Advanced Topics in Security (information assurance): Purdue

Instrumental groundbreaking work in security education has been spearheaded by Matt Bishop of UC Davis and Cynthia Irvine of the Naval Postgraduate School. Eugene Spafford of Purdue has also been extremely active in calling for better security education. For more on this important topic, see the "Education" department in IEEE Security & Privacy magazine <http://www.computer.org/security>.

Arming a normal infosec guy with a silly first-generation code scanner like ITS4 or a black box testing tool like Sanctum's Appscan rarely helps. Tools do not have enough smarts to turn network professionals into software people over night. Beware of security consultants who claim to be application security specialists when all they really know how to do is run ITS4 or Appscan and print out an incomprehensible report.

Start with software people

Security is much easier to learn about and grok than software development is. Good software people are very valuable, but software security is so important that these highly valuable people need to be repositioned. Also note that software people pay attention only to other software people, especially those with impressive scars. Don't make the mistake of putting lamers or newbies in front of a group of seasoned developers. The ensuing feeding frenzy is downright scary (if not hugely entertaining).

Identifying a responsible person or two is critical to a successful software security program (see Chapter 10). Not only is this important from an accountability perspective, but the sheer momentum that comes from a dedicated person can't be matched. If you want to adopt a new way to do code review (using a tool like Fortify), identify a champion and empower that person to get things done.

Often the most useful first person in a software security group is a risk management specialist charged with addressing software security risks that have been uncovered by outside consultants. Appointing a risk management person makes it much less likely that important results will be swept under the rug or otherwise forgotten by very busy organizations (and who is not busy these days?). The risk management specialist can be put in charge of the RMF.

Mentoring or otherwise training a new software security person may be impossible if there are no existing software security types in your organization. If that's the case, hire outside consultants to come and help you boot up a group. The extensive experience and knowledge that software security consultants have today are as valuable as they are rare, but it is well worth investing in mentoring your people in order to build that capability.

Ultimately, you want two types of people to populate your software security group: black hat thinkers and white hat thinkers. If you're lucky, you'll find people who can switch hats at, um, the drop of a hat. But more likely, you'll have some good constructive types (who naturally swing toward the white hat side) and some devious destructive types (who naturally swing toward the black hat side). In some sense, this matches the distinction between builders and auditors. You need both, of course, because the touchpoints demand both. Know that the builders are much more important than the auditors, though.

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