Topics


Blogs


Forums


Samples


Media


Labs


Resources

 




DevCentral > Weblogs > Lori MacVittie - Two Different Socks
 TLS Man-in-the-Middle Attack Disclosed Yesterday Solved Today with Network-Side Scripting
posted on Friday, November 06, 2009 12:30 PM

Yesterday the blogosphere, twittosphere, and other-spheres were abuzz when a new TLS renegotiation man-in-the-middle attack was disclosed.

image

Interestingly enough, while we were all still reading about it and figuring out all the nuances, one of our own DevCentral members was out implementing a solution.

No, he’s not a vendor with a product to worry about, he’s just a “guy” trying to defend his web site and applications from potential attacks like this one. But he’s a guy with network-side scripting in his arsenal of web application security tools, and with that and his understanding of the very well-documented vulnerability he crafted a solution.

Colin documents the iRule that addresses this vulnerability in his 20LoL post for the week, and so I won’t repost the code. You can also view the forum thread [registration required] in which “Lupo” describes and discusses the solution.

What I love about this solution is not necessarily that it solves a particular vulnerability. That’s awesome, of course, and a great thing but in the coming weeks and months we’ll see a lot of solutions that address this particular vulnerability. What I really love about this solution is the speed with which it was implemented. The vulnerability was disclosed yesterday and Lupo had a solution today, which he generously shared with thousands of others who can immediately put into use the same solution.

A lot of folks talk about agility and how solution X or Y enables organizations to respond rapidly to changing market/business conditions, but rarely do you see as solid an example as this one. From disclosure to solution in one day. That’s agility in action.

UPDATE (12/09/2009): The code referenced in Colin's post and the forums contains a "TCP::close" near the end of the iRule. Based on implementations this needs to be changed to be simply "reject" to avoid causing a problem with core processing.

Follow me on Twitter    View Lori's profile on SlideShare  friendfeed icon_facebook

AddThis Feed Button Bookmark and Share

Related blogs & articles:



 
      

Feedback


11/6/2009 12:35 PM
Gravatar I would have included a "See? I told you so..." considering your very timely post on WHEN being more important than WHERE:

devcentral.f5.com/.../...application-security.aspx
Jason Rahm

11/10/2009 11:01 AM
Gravatar This post was mentioned on Twitter by lmacvittie: New post: TLS Man-in-the-Middle Attack Disclosed Yesterday Solved Today with Network-Side Scripting: Yesterday the b... http://bit.ly/44dwg8
uberVU - social comments

11/10/2009 11:12 AM
Gravatar We have SSL certificate configured for our clients on BigIP. Could you please let me know if we are exposed to this vulnerability. We currently are not running any iRules, do we need to run the rules and if yes, can I please get an example?

thanks
Nadeem
Nadeem

11/10/2009 11:17 AM
Gravatar @Nadeem

My understanding of the SSL/TLS MiTM attack is that it is specific to the protocol, not a product, and thus any implementation of SSL is suspect.

Whether or not you should be running the iRule is really based on how much risk you are willing to accept. If you have a low-tolerance for risk and prefer a "better safe than sorry" approah, the iRule offered by Lupo is documented here by DC iRules Guru Colin Walker: devcentral.f5.com/.../...ng-header-re-writing.aspx

If you have questions/need assistance with implementing the iRule please log in to the forums and join this thread:
devcentral.f5.com/Default.aspx
Lori MacVittie
 Leave Feedback
Title  
Name  
Email
Url
Comments   
Please add 8 and 3 and type the answer here: