Defending yourself is not a crime
When I wrote last week post incipt, I wasn’t aware I was going to make a prophecy about 2013 and application security.
But I did it.
CVE-2013 and CVE-2013 and a framework that has bugs
Looking at RoR community I may feel the sensation that people are comfortable their framework allows them to cook a web app in minutes, that it can give them helpers in order to write software the agile way and that is rock solid: robust and secure.
Please don’t misunderstand my point here. I do believe Rails is an outstanding framework with some advanced security features like:
- html_safe helpers to filter output
- automagically defense against basic SQL Injection patterns via ActiveRecord
- anti cross site request forgery token
But, like almost every piece of code written by human being, also Rails framework has bugs and, as consequence, even security ones.
Keeping underlying framework up-to-date is an critical activity a security engineer has to deal with nowadays. Updates must be:
- possible: you can listen a lot of stories about very customized legacy application that they cannot be update anymore since the developers are no longer available or since updating some library would break anything
- smooth: ideally your updating task would not be longer than a full day of work. If it is and your codebase is smaller then the Linux Kernel than you’re missing something
In order to achieve this you have to trust and use your underlying framework but you don’t want to became a slave of its features. This leads to a simple mantra I use everytime I talk to a developer about application security:
Choose a framework that is security aware but don't rely on that. Your code must handle and validate all inputs coming from HTTP request, filesystem, database, whatever.
This week two vulnerabilities were found again on ActiveRecord and ActionPack Rails framework components. A Metasploit exploit was delivered out-of-the-box exploiting the latter leading to a remote command execution. Panic.
Just a recall to update your Rails installation to the latest available and add some code managing your inputs before using it. You will save a lot of troubles if you’re confident about an attacker can’t pass you a malformed value since you made input validation.
To mitigate this you have only to disable your browser Java plugin, waiting to Oracle to patch this one.
Off by one
Don’t miss the opportunity to implement a real input validation policy for all the stuff related to your web experience. Life is too short to recover from a system compromise just because you didn’t apply some if or regex to make your data safe.