tssci security

Short-term defenses for web applications

Before Mike Rothman posted something about the WhiteHatSec and F5 announcement, I really wasn't going to say anything negative or positive. Integrating web application security scanners with web application firewalls at first seems like a good idea. However, it appears that most people forgot about the issues with WAF's: they only prevent very few kinds of software weaknesses.

Enough with the WAF's already

My analysis is the following:

How do I define a critical security-related bug? How about ones based on time and state, which could allow checkout of items before paying for them? This is one of many examples.

Web application security scanners are awareness tools ; Web application firewalls are door stops

Web application security scanners are tools to be used for raising awareness. Not too many people are aware of or convinced of the need to secure web applications to any degree of managed risk. Web application security scanners can help get funding to necessary projects that should have happened years ago.

Also note that any consulting or software-as-a-service solutions for web application security that utilize web application security scanner technology (or worse, perform testing manually) also fit into this category.

Web application firewalls are a different story. These are purely door stops because they make awful paper weights. I classify all of this technology in the category of epic fail.

Want some examples of epic failure? How about two recent XSS vulnerabilities found in F5's management interfaces for their Big/IP product? Here's one in their search functionality. Oh look, another in their security reports.

However, my favorite (and I've been saving this one for a long time) comes with a huge debate on the F5 blog about whether or not you have to rewrite the code when security-related bug fixes are in order.

When Lori MacVittie of F5 attacks Mike Sutton of HP SPI Dynamics, Jeff Forristal of SPI's response is friendly and compromising. My comments got a little out of control because I honestly couldn't believe what F5 was saying to be true. I was really upset by this blog post, which clearly had zero understanding of either networks, systems, or applications.

Is F5 a security company?

The best part of this F5 blog post comes before F5 even gets an opportunity to respond to me. It's been several months (add to this fact that I'm sure that F5 "forgot" to install blog software that enables nofollow by default), and the blog spam that covers the page is still there. How could F5 possibly take web application security seriously if they can't block/deal-with something as simple as blog spam?

Secure SDLC solutions can be both short-term and long-term

I've been told that Secure SDLC solutions are only focused on the long-term, or they're "too idealistic" or "running to developers to put out the fire is the wrong approach". This is all untrue. There are plenty of solutions that every development shop can move towards, which will give immediate results for both quality and security. Yes, every development shop is different and has different goals than operations/security -- but this organizational change must happen.

Using Subversion for source-code revision control? Is your development environment tracking issues such as defects, but with the ability to add wiki notes as seen in Trac? Is there an automatic nightly build using continuous integration server software such as CruiseControl (or might you want a push-button approach as seen in Luntbuild)? Are your developers using logins (AKA Identity Management for you security people out there) that make them personally accountable to each piece of checked-in code, defect tracking issue, and failed build?

Some immediate SDLC wins

Developers have a solution that is bootable from a CDROM today. It's called Buildix. Buildix contains Subversion, Trac, CruiseControl, and an identity management solution to tie all of these together.

How does this help with security? Well, if your development team isn't doing the basics (and doing them well), then you can forget about other SDLC process improvements. The trick here isn't to push this as a security issue. Make it a quality issue. Say it has something to do with Sarbanes-Oxley. Oh - you're a private company? Consider looking at the BITS Shared Assessments Program (which has all but replaced SAS 70 Type II). There are many companies that don't need to meet S-OX 404 that still follow COBIT, ITIL, or ISO27K as much as possible, including using internal auditing aggressively.

Requirements gathering is the most important phase of any quality/security software development lifecycle. For those of you who aren't familiar with the V-Model and Fagan inspection -- it's important to note that these start in the requirements phase. Testing software shouldn't happen only by a QA team as acceptance testing. Peer review shouldn't be an after-thought that only applies to the code post-build.

Fagan inspection (complete as possible) and test cases (at least a few) should be handled before any design or decisions about the application are made. If the moderator is told that unit testing that looks for strict whitelist input validation on all HTML, CSS, XML, and Javascript is required -- he/she may be confused at first. Showing this person some simple XSS, CSRF, and XXE attacks with an awareness test (see web application security scanners, above) might help encourage this lead software engineer to understand some backstory.

My favorite short-term win for any Secure SDLC program is to integrate the concept of continuous-prevention development. Continuous-prevention development is Regression Testing 2.0.

Your IDE grew up but your development shop is stuck in 1999

Unit testing can take place in the IDE (as well as during integration testing at build time, which can be automated by a build server). Often this can also be done continuously. It can be combined with static checking and code coverage. Need runtime testing? Just add Canoo WebTest or Selenium during integration.

Additional security properties can also be tested in the IDE with some simple changes. Many developers don't know how to install their own web server, but any developer-tester should know how to run an embedded web server such as Jetty along with an embedded database such as H2 (or full solutions such as PicoContainer). It's almost to the point where not only are in-IDE continuous unit tests reality, but also component tests or full system tests.

In summary, continuous in-IDE system testing means that anything a web application security scanner can test -- a developer can perform more accurate tests while actually writing the code in real time. Of course, this will have less false positives, less false negatives, and allow for easier tuning and customization at much cheaper pricepoints (note: all of the software linked above is open-source). By adding "continuous-prevention" regression + fix checks, in-IDE unit testing prevents pilot error before costly peer review is even necessary.

The "A[OP]-Team"

There is no doubt that security testing, secure coding standards, secure code review, and other Secure SDLC improvements provide better alternatives to the classic "scan and patch" hamster-wheels-of-pain that web application security vulnerability assessment management solutions provide.

However, what about solutions such as Aspect-oriented programming (AOP)? Or integration of AOP and dependency injection? It looks to be possible to hire a team of coders to write code on top of your already existing codebase. This code will secure your code from all types of web application security risks. It won't just protect the OWASP T10-2007 A1-A2 critical software weaknesses (one of the limitations of a WAF), but also the other 640-some listed in the MITRE CWE node structure.

Would you consider hiring such a crack team of hotshot security developers?

*AOP and Dependency Injection are not long-term solutions. Any development shop with the proper expertise can implement these immediately. Consulting groups will start to make AOP/DI solutions available at a much lower overall cost than a $25K/year SaaS scanning solution combined with a $70K WAF appliance pair.*

Posted by dre on Tuesday, March 11, 2008 in Defense and Security.

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