Prior to installing Fiddler 4 on my computer, Cortana, Windows Store, Updates, UWP Apps, etc... Were all capable of using the internet flawlessly. However, after installation whenever Fiddler 4 is not open/active my entire OS is virtually destroyed by being unable use the majority of features.

I reset all system policies, ran Windows SFC/DISM, malware/virus scans, and registry integrity checks - all clear. I have also reset the Wininet Catalogs, Set Manual DNS, Flushed DNS Cache and renewed IPConfig. There are no proxies defined under Windows Settings, IE Explorer, nor Control Panel.

Thus I removed Fiddler 4 with a complete uninstall expecting it would undo the damage it has caused, needless to say, it has not resolved the problem?

(Even running another proxy does not work, it is truly bound to this malicious like application.)

Step to reproHi,

I've got some problem tracing reauest between web application. I describe below how to reproduce.
Hope you can help me :)

Requirements:
windows10
Visual Studio 2017
.netcore


Step to reproduce:

- Launch a first Instance of Visual Studio, File -> New -> Project -> .Net Core -> ASP.NET Core Web Application -> OK -> Web APi -> OK.
Go into properties of Web Application, tab Debug, and get the App Url.
Example: instance 1 : http://localhost:58557/

- Launch a second instance of Visual Studio, and do the same as step 1.
Example: instance 2 : http://localhost:50214/

- In first instance, go in file Controllers -> ValuesCOntroller
Replace first method by this code :
        // GET api/values
        [HttpGet]
        public IEnumerable<string> Get()
        {
            WebProxy proxy = new WebProxy("http://127.0.0.1:8888/", false);
            HttpClientHandler handler = new HttpClientHandler()
            {
                Proxy = proxy,
                UseProxy = true,
                PreAuthenticate = true,
                UseDefaultCredentials = true,
            };
            HttpClient httpClient = new HttpClient(handler);
            //HttpClient httpClient = new HttpClient();
            var t = httpClient.GetAsync("http://localhost:50214/api/values").Result.Content.ReadAsStringAsync();
            return new string[] { "value1", "value2" };
        }

Be careful, replace http://localhost:50214 with the URL of your second instance.
This code will call second instance using proxy 127.0.0.1:8888.

- Launch Fiddler, and check that proxy is correctly enabled and set to 127.0.0.1:8888.

- Launch both instance of web application.

- Call first Web Application using IE, postman or whatever... GET http://localhost:58557/api/values

- In fiddler, you'll see one line :
1    200    HTTP    localhost:58557    /api/values    30        application/json; charset=utf-8    postman:9972    

- The call to the second web application is not visible.


        

HI

In the fiddler there is a feature "Reissue from composer", which I try to do from FIddlerCore .net standard.

But I don't know how to do it..

In "FiddlerApplication.BeforeRequest += (Session oS) => {" I'm trying to :

if (oS.url.IndexOf("original_url") >=0) {
                            oS.url = "new_url";
                            oS.utilSetRequestBody(File.ReadAllText("xml-body-request"));
                           }
but it doesn't work, like I miss something. ResponseBody has 0 bytes in such approach..

Any idea what is missing here ?

 

Best regards 

---------------------------
Uncaught Exception in Session #9
---------------------------
Fiddler has encountered an unexpected problem. If you believe this is a bug in Fiddler, please copy this message by hitting CTRL+C, and submit a bug report at http://www.telerik.com/forums/fiddler.

Cannot access a disposed object.

Object name: 'WinHttpAutoProxy'.

Type: System.ObjectDisposedException
Source: Fiddler
   at “.Ÿœ.ƒ•(String •, String& ‘‰, String& ”) in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\FiddlerCore\PlatformExtensions\Windows\FiddlerCore.PlatformExtensions.Windows.Shared\WinHttpAutoProxy.cs:line 52

   at .‚•.œ(String –, IPEndPoint& žœ) in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\AutoProxy.cs:line 142

   at Fiddler.Proxy.FindGatewayForOrigin(String sURIScheme, String sHostAndPort) in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\Proxy.cs:line 805

   at Fiddler.ServerChatter.Œ() in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\ServerChatter.cs:line 1056

   at Fiddler.Session.‘() in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\Session.cs:line 3651

   at Fiddler.ServerChatter.ŽŒ() in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\ServerChatter.cs:line 1520

   at Fiddler.ServerChatter.Œ() in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\ServerChatter.cs:line 1474

   at Fiddler.Session.‘() in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\Session.cs:line 3651

   at Fiddler.ServerChatter.ŽŒ() in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\ServerChatter.cs:line 1520

   at Fiddler.ServerChatter.Œ() in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\ServerChatter.cs:line 1474

   at Fiddler.Session.‘() in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\Session.cs:line 3651

   at Fiddler.Session.(Object ) in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\Session.cs:line 3426


Fiddler v5.0.20173.50948 (x64 AMD64) [.NET 4.0.30319.42000 on Microsoft Windows NT 6.1.7601 Service Pack 1] 
---------------------------
OK   
---------------------------

Hi,we're using fiddlercore + selenium get on the traffic acquisition. it's in single-threaded is ok, we need in multiple-thead environment  to using fiddlercore. but we found out it's maybe no't support start Up too many instances. Can u tell me do it? or some better metod.  this pages have resemble  the answer :https://www.telerik.com/forums/separate-traffic-from-multi-threaded-program  but i don't understand.

“for instance via a custom request header (X-THREAD-ID: 123) that FiddlerCore could delete before forwarding the request to the target.”

hi

I'm trying to use CONNECT command of http proxy as generic tcp tunnel in our project. It's not SSL
Firstly I had used it for one of our services where client sends requests to a server and the servers responds (in other words the client is initiator of activity) - it seems all worked fine with fiddler.

Now i have tried to use same technique for tunneling ftp connection (control and data in passive mode). And this doesn't work, because in ftp control connection server firstly send greeting message to a client and the client waits for them, it doesn't send anything until get this greeting.
It looks like fiddler doesn't pass first data packet from the server to the client when server is initiator of conversation.
As result when fiddler sniffs for a SSL handshake it doesn't see traffic from the client and drops the connection.
Even disabling option "Decrypt HTTPS traffic" doesn't help.

IMHO, it's bug in fiddler. it must not assume that CONNECT used only for SSL

Hi all.

 

I am trying to debug a (java) application that does not obey proxy rules. As a result I have been forced to use Proxifer to redirect all traffic to Fiddler. This seems to be working fine and I can see the initial SSL negotiation but the actual request that follows fails with the following line in the log:

17:36:17:8627 Session #1868 detaching ServerPipe. Had: 'direct->https/X.X.X.X:5989' but needs: 'direct->https/X.X.X.X:443'

X.X.X.X is the same (and correct) on both sides. The server I am connecting to is indeed running an SSL service on port 5989 (and cannot be changed to 443).

Any ideas on what I can do to fix this?

Fiddler version: v5.0.20173.50948 for .NET 4.6.

Hi,

I Need some help

I want to connet to a Server by JavaScript from my Homeserver.

The Server i want to connect, uses "Digest authentification", when I attempt, I get the following Response:

{"jsonrpc":"2.0","result":{"realm":"Insta-NetBox","domain":"","uri":"/jsonrpc//management","nonce":"d4d4cceede1cd30ad082bab2d18b03f7741db5d2","opaque":"736873746d383364706b3772746b3335356b70356d7539306636","algorithm":"sha","qop":"auth"},"id":"1"

 

I know the Password (I can log in with a web-application).

 {"jsonrpc":"2.0", "method":"userLoginDigest", "params":{"userName":"admin", "uri":"/jsonrpc//management", "qop":"auth", "cnonce":"77F63B06D02BA690D0AC929CF785F009E75F2BD" , "nc":"00000001" , "response":"ef0caa10c9dd87225e459312cd9d8686d6f6fcbc" , "realm":"Insta-NetBox", "nonce":"d4d4cceede1cd30ad082bab2d18b03f7741db5d2", "algorithm":"sha", "opaque":"736873746d383364706b3772746b3335356b70356d7539306636"}, "id":"2"}

I get "Authorization failed"....

according to RFC2617 I calculate the hashesfor the Response string and the "cnonce" value als a 40 sign random-string

Does someone have a chance to verify my calculation?

 

 

 

 

 

Hi

I've just downloaded FiddlerCore and I plan to use it my .net core project.

My .net Core SDK version is v2.1.4 . The latest one when I write this post. 

I use the sample code, I did "dotnet restore -s <path_to_nupkg_files>" , run the code trusted the certificate...and..... nothing got captured.

Edge,IE. Nothing . Presssing L, S shows nothing..

 

Any ideas what I'm doing wrong ?

 

Best regards

 

 

 

I have downloaded fiddler and mono and put fiddler on my desktop

and when get to the step of mono Fiddler.exe, it says 

 

Cannot open assembly 'Fiddler.exe': No such file or directory.

 

Please help!

Thanks