Security Concerns When Working With New Technologies

Question

Do you find that when you work with a new technology that you're never quite sure what security gaps your leaving in your code?

I've been working with ASP.Net Web Forms for about 5 years now and am fairly confident my code is at least secure enough to stop most known attacks. Looking back a lot of my early code I have unknowingly left gaps in a lot of the security areas especially query strings and viewstate but I feel over time I learnt what the vulnerabilities were and made sure I didn't make the same mistakes again.

However I've recently started a new project in ASP.Net MVC and I really have no idea what security holes I'm leaving open. This reason alone is almost putting me off going forth with this. I'm reading up on it like crazy at the minute but am sure I've not learnt nearly enough to make it as secure as I could with Web Forms. What do you guys do to make sure you don't leave yourself open to attack?

Edit : Starting Bounty as Curious to see if there are any more opinions

Answer 1

This is a very difficult question with probably no great answer. However, there are a couple things you can do to increase the possibility of keeping yourself safe when using new technologies.

1. Keep the following in mind: there are three types of vulnerabilities. Ones that are unique to the framework you are using (e.g. Ruby on Rails public controller problems), ones that are unique to the type of application you building (e.g. Web Applications have to worry about XSS), and ones that are unique to your application in particular.
2. Identify how the new technology you are using mitigates application type security vulnerabilities. For example, how does ASP.Net MVC mitigate XSS? How does it mitigate SQL Injection? If there is no answer in the documentation, then figure out how you are going to address these common classes of vulnerabilities. Also, take pause because if the framework doesn't mitigate these issues then maybe the frameworks developers haven't prioritized security and may not have written a very robust framework.
3. Figure out why you need security and what you are trying to protect. For example: Does your application require authorization before viewing sensitive data? If so, determine what features the framework provides for authorization.
4. Look for a security section in the documentation. Often known issues are documented but people focus so much on getting their problem solved that they don't look for it.
5. Code defensively and be aware of how user input is used. Be generous in defining what is user input. For example, the querystring or post fields are obvious, but in many MVC frameworks the URL dictates what code runs (e.g. see Ruby Routes vulnerability). Be very aware of how the data is handled
6. Stress test your business logic and figure out how it could potentially be abused.

So in short: Handle user input carefully, read the existing documentation, determine what security you require, and figure out how the framework mitigates common vulnerability classes. Being aware that security is a priority and paying attention is 50% of the fight.

Answer 2

I think a LOT of what you learned about with ASP.NET is transferable to ASP.NET MVC. It's still HTML (exploits: XSS) over HTTP (exploits: all input [cookies, URL parameters, form input, headers] can be forged, session hijacking, CSRF) with a database back end (exploits: SQL injection).

I would recommend Steve Sanderson's book on ASP.NET MVC titled Pro ASP.NET MVC Framework. It has an entire chapter dedicated to these topics.

Check out Chapter 13 'Security and Vulnerability' from the Table of Contents for the book.