Skip to main content

So, How will you work with a Proxy on NTLM...?

Most SharePoint environments today are using NTLM (the default) as the authentication protocol. NTLM authentication is a challenge-response scheme, consisting of three messages, commonly referred to as Type 1 (negotiation), Type 2 (challenge) and Type 3 (authentication). For more information on NTLM go to http://en.wikipedia.org/wiki/NTLM as discussion over NTLM and its working in out of scope for this post.
The problem with setting up Web Proxies (Paros, Burp etc) is that they work fine with other types of authentication (Custom, Basic) but where there's NTLM is used the chain breaks between the proxy and the server resulting in non function of the application.
As soon as the proxy wants to connect to the server it gets the following '401:Unauthorized' response:
HTTP/1.1 401 Unauthorized Server: Microsoft-IIS/7.5 WWW-Authenticate: NTLM X-Powered-By: ASP.NET MicrosoftSharePointTeamServices: 14.0.0.4762 Date: Sat, 04 Sep 2010 06:38:22 GMT Content-Length: 0

You can't capture requests/responses through the proxies at all. I was also facing the same problem. Ronnie suggested me to use a tool which will sit between the proxy and application server. Which will handle all the NTLM communications between the proxy and the server...cool! The tool is called NTLMaps and can be downloaded here: http://ntlmaps.sourceforge.net/
'NTLM Authorization Proxy Server' (NTLMAPS) is a proxy software that allows you to authenticate via an MS Proxy Server using the proprietary NTLM protocol
Now the scenario was like this:

How to setup the chain:
1. Set the proxy server address in your browser to any port, lets say-localhost:8080

2. Set the Local proxy setting in the Web Proxy (Paros) as the same as you did for the browser so that the can communicate with each other on same port- localhost:8080
3. In Connection section of the Paros set the Outgoing proxy port no. as 5865. By default, the NTLMAPS tool runs on the same port. Now Paros will forward all requests obtained by browser to NTLMAPS at 5865.


4. Now start the NTLMAPS tool:

5. Now go to your browser and access the application. You will be able to capture request -response as usual as if you were working with custom authentications! The tool does the NTLM communications for you in the background without your knowing. You can see the communications also on the screen:



Happy Pentesting ! :)

Comments

Post a Comment

Popular posts from this blog

Using an AirPcap device in Windows with Wireshark

Capturing wireless traffic in a Windows environment is unfortunately not as easy as a setting change. As with most Windows-based software, drivers in Windows are often not open source and do not allow for configuration change into monitor mode. With this in mind, we must use a specialized piece of hardware known as an AirPcap device. Once you have obtained an AirPcap device you will be required to install the software on the accompanying CD to your analysis computer. The configurable options include: • Interface - Select the device you are using for your capture here. Some advanced analysis scenarios may require you to use more than one AirPcap device to sniff simultaneously on multiple channels. • Blink LED - Clicking this button will make the LED lights on the AirPcap device blink. This is primarily used to identify the specific adapter you are using if you are using multiple AirPcap devices. • Channel - In this field, you select the channel you want AirPcap to listen on. Extension C...
5 comments
Read more

Anti CSRF header

Recently I came across an application which was preventing crsf attacks using a unique non-traditional approach. In traditional approach the csrf is thwarted by embedding unique random tokens, called nonce, in each sensitive page. But this application, which was making ajax calls and used jQuery, was creating a header to identify the valid and invalid requests altogether. The idea is to generate a custom header, x-session-token in this case, with every request which is considered sensitive and includes any sort of transaction. For example: xhr.setRequestHeader('x-session-token', csrf_token)   At the server level, server checks for this header if found request is fulfilled, otherwise rejected. We need to use xhr calls for making use of this technique, not useful in regular POST and GET requests. Since, I was not aware of this kind of countermeasures, probably, since most of the applications I did were using standard requests. So, I searched a bit and found even Go...
4 comments
Read more

Some one watching where you visited!

Yes... Mozilla has been susceptible to browser-history stealing java script code. Today, Giorgio posted some cool information about the exploit. Mozilla is already working on this. This bug has been reported. Actually they have set up a web site to show the proof-of-concept. Visit www.statrpanic.com in FF,Safari or Netscape and it will tell you which websites have you been already ! But I am not sure it will work in IE or not because my IE is not responding to the website. Clearing history of visited website makes you safe to this attack. I mean this is one way..may be there are other ways to exploit this. But I have found this effective. Try it yourself in FF and then in IE and see the results.
Post a Comment
Read more