Thursday, June 3, 2010

Questions & Answers from AppSensor Presentation

Today's presentation on Automated Application Defenses to Thwart Advanced Attackers was a success with great attendance and many good questions. Missed the presentation? Check out the recorded version here.

Links of interest:
OWASP AppSensor Project
AppSensor Detection Points
AppSensor Code

Not enough time was available to answer all of the questions so I thought I'd post those questions and answers here:

Q: Why not build secure application right away? Training the developer and thorough penetration testing prior to release the app to the internet?
A: Totally agree. The application intrusion detection concepts described within the presentation are intended to be performed after you've developed your secure application. So take all of your current security practices: threat modeling, secure SDLC, penetration testing, etc, and then add on the application intrusion detection concepts described by AppSensor.  This is intended to be a method of detecting and eliminating malicious users before they possibly locate a vulnerability in your app (that you weren't aware of).

Q: Isn't that just a little like the "honey-pot" strategy? Why not build a real attacker trap in each application, which is not reachable by normal usage of the application by a legitimate user?
A: It is very similar. We are basically implementing detection points that can be though of as "trip-wires" or "honey pots". The detection points are intended to detect a user doing something bad.  A good detection point will have a near-zero false positive rate.

Q: I've always referred to frameworks like this as traffic and/or application policing strategies. As you inspect traffic or data, you dynamically detect malicious behavior and deny applicable end points/attackers.
A: Yes, that is basically the idea here.  AppSensor just helps people implement this idea by providing the types of traffic/attacks that they should be looking for. Also, we are working to provide the code via ESAPI.

Q: How well would the AppSensor integrate with web sites created with Lotus Domino or SAP's web interface?
A: There's no reason AppSensor couldn't work in any web application provided you have the ability to modify the source code.

Q: After a while the attacker will know the pattern that you are checking for .. thus they might get brighter as well. First question - how do we hold pace with the attacker's learning curve. Second question - how do we know, that our traps are working? Should we ad a monitoring interface to the traps themselves that we use to generate test trapping responses?
A: The attackers may get smarter, but odds are you are already facing very smart attackers. You don't really need to worry about an attacker learning about the detection points if you ultimately lock out the malicious user's account anyway. However, if account creation is not controlled then there is the potential that the attacker could just create another account and continue probing. But, the attacker would have to be very interested in your site to recreate a new account after every 3 failed attack attempts.
When building the detection points (traps) you should definitely test each one of them prior to production deployment. You'll be testing that the detection point properly captures the particular attack it was designed for.

Q: We should not generate a warning message for the attacker but stay silent and chase him. (Referring to the option to send a message back to the user when the detection point fires).
A: This is totally up to you as the application owner.  Some applications may wish to display a warning message to the user while other apps will remain quite as you indicated.

Q: We should enable the traps (detection points) after we have done our own penetration testing and test the traps?
A: Yes, definitely test the detection points to ensure they are working correctly. Its also worthwhile to observe how the detection points fire during a penetration test.  This might also lead you to new detection points that need to be implemented.

Q: Have you thought about a standardized central monitoring device that these trapped application can interface with?
A: Yes, you could format your log message and then use centralized monitoring via ArcSight, QRadar or any other Security Information and Event Manager.

Hope this helps. Please post any other questions.

-Michael Coates