Posts tagged web_apps

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Do Open Source Devs Get Web App Security?  Does Anybody?

Note: I’ve updated this article after getting some feedback from Alexander Limi.

A colleague of mine who is dealing with Plone, a CMS system built atop Zope, pointed me to a rather disturbing document in the Plone Documentation system, one that I feel is indicative of a much larger problem in the web app dev community.

The first describes a hole (subsequently patched) in Plone that allowed users to upload arbitrary JavaScript.  Apparently no input or output filtering was being done.  Certainly anyone familiar with XSS attacks can see the potential for stealing cookie data, but the article seems to imply this is simply a spam issue:

Clean up link spam

Is this a security hole?
No. This is somebody logging in to your site (if you allow them to create their own users) and adding content that can redirect people to a different web site. Your server, site and content security is not compromised in any way. It’s just a slightly more sophisticated version of comment spam. If you open up your site to untrusted users, there will always be a certain risk that people add content that is not approved. It’s annoying, but it’s not a security hole.

Well, yes, actually, it is a security hole.  If one can place JavaScript on your site that redirects the user to another page, they can certainly place JavaScript on your site that grabs a user’s cookie data and redirects that to another site.  Whether or not they’ll get something useful from the data varies from app to app, of course. What’s worrisome is that it appears as if one of Plone’s founders (the byline on this document is for Alexander Limi, whose user page describes him as “one of Plone’s original founders.”) doesn’t seem to think this is a security issue. After getting feedback from Alexander Limi, it seems clear that he does understand the user-level security implications of the vulnerability, but was trying to make the distinction that there was no security risk to the Plone site itself.  Still, the language of the document is (unintentionally) misleading, and it’s very reminiscent of the kinds of misunderstandings and excuses I see all the time in open-source web app development.

The point here is (believe it or not) not to pick on Plone.  This is a problem prevalent in most open source development (and in closed source dev, from my experience).  People who simply shouldn’t be doing coding are doing the coding—and the implementation and maintenance.

Let’s be blunt: A web developer is not qualified to do the job if he or she does not have a good understanding of web application security concepts and techniques.  Leaders of development teams must stop allowing developers who are weak on security techniques to contribute to their products, and managers need to stop hiring candidates who do not demonstrate a solid secure programming background.  If they continue to do so, they demonstrate a lack of concern for the safety of their customers.

Educational initiatives must be stepped up to address this, both on the traditional academic level and in continuing education/training programs.  Students in web development curriculums at the undergrad level need to be taught the importance of security and effective secure programming techniques.  Developers in the workforce today need to have access to materials and programs that will do the same.  And the managerial level needs to be brought up to speed on what to look for in the developers they hire, so that under-qualifed and unqualified developers are no longer the norm on most web dev teams.


Using mod_security to block PHP injection attacks

mod_security is an essential tool for securing any apache-based hosting environment.  The Pathfinder High Performance Infrastructure blog has posted a good starter piece on using mod_security to block email injections.

One of the more common problems with PHP-based applications is that they can allow the injection of malicious content, such as SQL or email spam. In some cases we find that over 95% of a client’s ISP traffic is coming from spam injection. The solution? Grab an industrial size helping of Apache mod_security.

BTW, Ivan Ristic’s (the developer of mod_security) Web Security Blog is well worth a spot in your blogroll.

(Edit: fixed title.  Duh.)

Web App Security - The New Battlefront

Well, we’re all pretty beat from this year’s Symposium, but things went off pretty well.  Along with lots of running around to make sure posters showed up and stuff, I was able to give a presentation called Web Application Security - The New Battlefront.  People must like ridiculous titles like that, because turnout was pretty good.  Anyway, I covered the current trend away from OS attacks/vandalism and towards application attacks for financial gain, which includes web apps.  We went over the major types of attacks, and I introduced a brief summary of what I feel needs to be done in the education, tool development, and app auditing areas to improve the rather poor state of affairs.  I’ll expand on these topics more in the future, but you can see my slides and watch the video for now: