So, first let me apologize for being in way over my head.  Now that that's out of the way....

I was wondering if someone could maybe help me explain why an API call made from .NET (specifically the Invoke-RestMethod cmdlet in powershell) might return a 401 Auth Error when executed without fiddler, but return data as expected while fiddler is open?  This behavior occurs using both HTTP and HTTPS (I found an article from way back mentioning Fiddler used a specific TLS regardless of the client request, but this does not seem to be the case anymore).

I've typically only interacted with this particular API via PHP and cURL, but I needed a windows application.

It would seem to me that the explanation is that Fiddler is somehow modifying the request my application is sending, but I have no idea how to look for that.

If this isn't the correct place for this question, my bad.

 

Hello forum


does FiddlerCap capture all 7 OSI Layers or only "connections" ?


Thank you!

Joe

Hi -- I tried installing Fiddler Everywhere for my MBP and i enabled Capture HTTPS Traffic and trusted the root Certificate also. I am still not able to capture the traffic in Fiddler.

hello fiddler4's latest update can't decompress https://bit.ly/2ZkNmAk this link's content

Подробная информация об использовании оперативной 
(JIT) отладки вместо данного диалогового 
окна содержится в конце этого сообщения.

************** Текст исключения **************
System.NullReferenceException: Ссылка на объект не указывает на экземпляр объекта.
   в Fiddler.frmViewer.š(Object , EventArgs ) в C:\Jenkins\Fiddler_Windows\workspace\Fiddler2\Fiddler.Shared\Viewer.cs:строка 9983
   в System.Windows.Forms.Form.OnLoad(EventArgs e)
   в System.Windows.Forms.Form.OnCreateControl()
   в System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
   в System.Windows.Forms.Control.CreateControl()
   в System.Windows.Forms.Control.WmShowWindow(Message& m)
   в System.Windows.Forms.Control.WndProc(Message& m)
   в System.Windows.Forms.ScrollableControl.WndProc(Message& m)
   в System.Windows.Forms.Form.WmShowWindow(Message& m)
   в System.Windows.Forms.Form.WndProc(Message& m)
   в Fiddler.frmViewer.WndProc(Message& m) в C:\Jenkins\Fiddler_Windows\workspace\Fiddler2\Fiddler.Shared\Viewer.cs:строка 12465
   в System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   в System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   в System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)


************** Загруженные сборки **************
mscorlib
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.235 (RTMGDR.030319-2300)
    CodeBase: file:///C:/WINDOWS/Microsoft.NET/Framework/v4.0.30319/mscorlib.dll
----------------------------------------
Fiddler
    Версия сборки: 5.0.20202.18177
    Версия Win32: 5.0.20202.18177
    CodeBase: file:///C:/Program%20Files/Fiddler/Fiddler.exe
----------------------------------------
System
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.232 built by: RTMGDR
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System/v4.0_4.0.0.0__b77a5c561934e089/System.dll
----------------------------------------
System.Core
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.1 built by: RTMRel
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Core/v4.0_4.0.0.0__b77a5c561934e089/System.Core.dll
----------------------------------------
System.Windows.Forms
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.235 built by: RTMGDR
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Windows.Forms/v4.0_4.0.0.0__b77a5c561934e089/System.Windows.Forms.dll
----------------------------------------
System.Drawing
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.1 built by: RTMRel
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Drawing/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll
----------------------------------------
Telerik.NetworkConnections
    Версия сборки: 0.1.2.0
    Версия Win32: 0.1.2.0
    CodeBase: file:///C:/Program%20Files/Fiddler/Telerik.NetworkConnections.DLL
----------------------------------------
System.Configuration
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.1 (RTMRel.030319-0100)
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Configuration/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Configuration.dll
----------------------------------------
System.Xml
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.1 built by: RTMRel
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Xml/v4.0_4.0.0.0__b77a5c561934e089/System.Xml.dll
----------------------------------------
mscorlib.resources
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.235 (RTMGDR.030319-2300)
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/mscorlib.resources/v4.0_4.0.0.0_ru_b77a5c561934e089/mscorlib.resources.dll
----------------------------------------
Xceed.Zip.v5.4
    Версия сборки: 5.4.13572.13590
    Версия Win32: 5.4.13572.13590
    CodeBase: file:///C:/Program%20Files/Fiddler/Xceed.Zip.v5.4.DLL
----------------------------------------
Xceed.Compression.Formats.v5.4
    Версия сборки: 5.4.13572.13590
    Версия Win32: 5.4.13572.13590
    CodeBase: file:///C:/Program%20Files/Fiddler/Xceed.Compression.Formats.v5.4.DLL
----------------------------------------
Xceed.Compression.v5.4
    Версия сборки: 5.4.13572.13590
    Версия Win32: 5.4.13572.13590
    CodeBase: file:///C:/Program%20Files/Fiddler/Xceed.Compression.v5.4.DLL
----------------------------------------
Xceed.FileSystem.v5.4
    Версия сборки: 5.4.13572.13590
    Версия Win32: 5.4.13572.13590
    CodeBase: file:///C:/Program%20Files/Fiddler/Xceed.FileSystem.v5.4.DLL
----------------------------------------
System.Windows.Forms.resources
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.235 built by: RTMGDR
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Windows.Forms.resources/v4.0_4.0.0.0_ru_b77a5c561934e089/System.Windows.Forms.resources.dll
----------------------------------------
System.ComponentModel.Composition
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.ComponentModel.Composition/v4.0_4.0.0.0__b77a5c561934e089/System.ComponentModel.Composition.dll
----------------------------------------
Telerik.NetworkConnections.Windows
    Версия сборки: 0.1.2.0
    Версия Win32: 0.1.2.0
    CodeBase: file:///C:/PROGRAM%20FILES/FIDDLER/PLUGINS/NETWORKCONNECTIONS/TELERIK.NETWORKCONNECTIONS.WINDOWS.DLL
----------------------------------------
MetadataViewProxies_1e031cd0-3f35-4522-83aa-273e160f99e6
    Версия сборки: 0.0.0.0
    Версия Win32: 4.0.30319.1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.ComponentModel.Composition/v4.0_4.0.0.0__b77a5c561934e089/System.ComponentModel.Composition.dll
----------------------------------------
System.ComponentModel.Composition.resources
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.ComponentModel.Composition.resources/v4.0_4.0.0.0_ru_b77a5c561934e089/System.ComponentModel.Composition.resources.dll
----------------------------------------
Standard
    Версия сборки: 2.6.2.0
    Версия Win32: 2.6.2.0
    CodeBase: file:///C:/Program%20Files/Fiddler/Inspectors/Standard.dll
----------------------------------------
SyntaxView
    Версия сборки: 2.6.2.0
    Версия Win32: 2.6.2.0
    CodeBase: file:///C:/Program%20Files/Fiddler/Inspectors/SyntaxView.dll
----------------------------------------
FiddlerOrchestra.Addon
    Версия сборки: 1.0.20202.16135
    Версия Win32: 1.0.20202.16135
    CodeBase: file:///C:/Program%20Files/Fiddler/Scripts/FiddlerOrchestra.Addon.dll
----------------------------------------
FiddlerOrchestra.Connection
    Версия сборки: 1.0.20202.16135
    Версия Win32: 1.0.20202.16135
    CodeBase: file:///C:/Program%20Files/Fiddler/Scripts/FiddlerOrchestra.Connection.dll
----------------------------------------
netstandard
    Версия сборки: 2.0.0.0
    Версия Win32: 4.6.26011.1
    CodeBase: file:///C:/Program%20Files/Fiddler/Scripts/netstandard.DLL
----------------------------------------
FiddlerOrchestra.Protocol
    Версия сборки: 1.0.20202.16135
    Версия Win32: 1.0.20202.16135
    CodeBase: file:///C:/Program%20Files/Fiddler/Scripts/FiddlerOrchestra.Protocol.dll
----------------------------------------
FiddlerOrchestra.Utilities
    Версия сборки: 1.0.20202.16135
    Версия Win32: 1.0.20202.16135
    CodeBase: file:///C:/Program%20Files/Fiddler/Scripts/FiddlerOrchestra.Utilities.dll
----------------------------------------
RulesTab2
    Версия сборки: 2.6.2.0
    Версия Win32: 2.6.2.0
    CodeBase: file:///C:/Program%20Files/Fiddler/Scripts/RulesTab2.dll
----------------------------------------
SimpleFilter
    Версия сборки: 2.6.2.0
    Версия Win32: 2.6.2.0
    CodeBase: file:///C:/Program%20Files/Fiddler/Scripts/SimpleFilter.dll
----------------------------------------
Timeline
    Версия сборки: 2.6.0.3
    Версия Win32: 2.6.0.3
    CodeBase: file:///C:/Program%20Files/Fiddler/Scripts/Timeline.dll
----------------------------------------
Microsoft.JScript
    Версия сборки: 10.0.0.0
    Версия Win32: 10.0.30319.1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/Microsoft.JScript/v4.0_10.0.0.0__b03f5f7f11d50a3a/Microsoft.JScript.dll
----------------------------------------
JScript Thunk Assembly
    Версия сборки: 0.0.0.0
    Версия Win32: 10.0.30319.1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/Microsoft.JScript/v4.0_10.0.0.0__b03f5f7f11d50a3a/Microsoft.JScript.dll
----------------------------------------
83GejTrl
    Версия сборки: 0.0.0.0
    Версия Win32: 10.0.30319.1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/Microsoft.JScript/v4.0_10.0.0.0__b03f5f7f11d50a3a/Microsoft.JScript.dll
----------------------------------------
bwpclfjs
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.232 built by: RTMGDR
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System/v4.0_4.0.0.0__b77a5c561934e089/System.dll
----------------------------------------

************** Оперативная отладка (JIT) **************
Для подключения оперативной (JIT) отладки файл .config данного
приложения или компьютера (machine.config) должен иметь
значение jitDebugging, установленное в секции system.windows.forms.
Приложение также должно быть скомпилировано с включенной
отладкой.

Например:

<configuration>
    <system.windows.forms jitDebugging="true" />
</configuration>

При включенной отладке JIT любое необрабатываемое исключение
пересылается отладчику JIT, зарегистрированному на данном компьютере,
вместо того чтобы обрабатываться данным диалоговым окном.

Hi, 

I'm trying to watch the API calls that my app is doing using Fiddler, I was able to do it in Android Phone, iOS, but not in Android TV box. 

For some reason, the .crt file is not being installed in the device. When I try to install it, the box shows me a message saying "Certificate not installed", so I'm not being able to capture the API calls. 



Did someone make Fiddler work in Android TV devices?

 

Thanks. 

Hi,

I am a newbie in using fiddler. I was trying to capture the HTTPS traffic from android app. I have installed the fiddler root certificate successfully on my android device but not able to capture the https traffic but  i see http calls going through tunnel.

Fiddler version : v5.0.20192.25091

Android OS version : 8.1.0

Please see the attached image for the fiddler settings applied and let me know if needed any more information.

Thanks

 

The beta app only shows version while starting up (on the dialog box for load screen) and has a menu where it should about section for open it. But once the app is loaded, there is no way to check what's the version of the application. Found this issue while reporting a UI bug today. Had to restart the app to check the load screen which had version info. 

I downloaded the latest version on website for Fiddler Everywhere Beta (v0.10.2) and upon fiddling around with it I found this reproducible issue. I'm running macOS Catalina (v10.15.3).

When you quickly and repeatedly click on the toggle for live traffic capture, fast enough that you don't let the toggle complete its animation / switch to either state, more than a couple of times (perhaps 10 times or more), the UI keeps toggling when you do and will settle on one state when you stop clicking. 

But after a few seconds, the toggle will starting switching again. Sometimes it takes more than a few seconds. It toggles a couple of times, and even if it finally stops itself at "on" state, the traffic is no longer captured. 

A user might not try to deliberately break the app like this, but perhaps there's something async going on with the UI that makes the actions happen later and also break the capture part.

 

Not sure what kind of system details might be required, but here's some generic info:

Application version: v0.10.2

OS version: Catalina (v10.15.3)

Processor: 2.3GHz Intel i5 (8GB DDR3 RAM)

Removing interception certificates via Fiddler option "Remove Interception Certificates" only removes them from Personal and Trusted Root Certification Authorities. Certificate that is located in Intermediate Certification Authorities is not removed. This certificate is not trusted after using "Remove Interception Certificates" and has status "This CA Root certificate is not trusted because it is not in the Trusted Root Certification Authorities store".
sigcheck -t[u]v doesn't show any warnings.
Tested this on both Windows 7 and 10. Tried refreshing certmgr, restarting it, and rebooting machine with no success - intermediate certificate is still there.