Fiddler 2 on Windows 8.1 and IE 11

3 posts, 1 answers
  1. Rod
    Rod avatar
    15 posts
    Member since:
    Jun 2011

    Posted 16 Oct 2014 Link to this post

    This morning I installed Fiddler 2 on my Vaio laptop, which has Windows 8.1 Professional installed on it. After installing it and running it for the first time I got a popup message (please see attached) that said that Windows 8.x uses something called "AppContainer" to restrict network traffic. I went to the help and it seemed to me that if I did click on the Win8Config button in Fiddler2, it would make the necessary changes, but it would also ask me which other apps I would want to open up for the same sort of network traffic. At this point I became hesitate. First, I don't completely understand the risks involved. Secondly, I do want to make it possible for Fiddler to access the network traffic it needs; I've found Fiddler to be very useful in trying to determine what's going on when things go wrong with my web applications. However I don't know which applications I would want to list in the exceptions list, and I don't know what impact it would have. I want the protection I need, but also be able to develop ASP.NET MVC and Web Forms apps, WPF, WCF and Web API, Windows Phone as well as Windows 8.x apps. I'd appreciate some direction on this, please.
  2. Answer
    Eric Lawrence
    Eric Lawrence avatar
    832 posts

    Posted 17 Oct 2014 Link to this post

    When you click Yes, you're taken to a document which explains what AppContainers are used for and why they can interfere with use of Fiddler.

    You can use the utility to allow all AppContainers access to Loopback; this is only relevant for Win8 apps, as other applications do not use AppContainer. Allowing access to loopback does very slightly increase the attack surface of those applications (e.g. their slight increase in power could be used by an attacker) but this isn't something I'd worry about as a security professional. In any case, when done using Fiddler with a Win8 app, you can simply disable the exemptions using the same utility. 

    Eric Lawrence

    Check out the Telerik Platform - the only platform that combines a rich set of UI tools with powerful cloud services to develop web, hybrid and native mobile apps.

  3. Sebastian
    Sebastian avatar
    1 posts
    Member since:
    Aug 2016

    Posted 16 Aug 2016 in reply to Rod Link to this post

    me gustariza< a a  a  ssdgdf  
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