Need More Info
Last Updated: 04 Jun 2021 07:02 by ADMIN
I ran Fiddler Classic on a remote PC via Windows Remote Desktop (RDP) on my laptop, which used an external large monitor for display. Both my laptop and the remote PC run Windows 10 OS. If somehow the remote desktop connection was temporarily lost (due to laptop going sleep or network glitch) and reconnected later, the Fiddler on the remote PC stopped responding to the mouse operation.
Need More Info
Last Updated: 08 Apr 2021 13:29 by ADMIN
Created by: Anton
Comments: 4
Type: Bug Report
0

Fiddler version: v5.0.20204.45441

If Fiddler is left for some time to work unattended then its memory usage is constantly growing.

I usually use Fiddler with some Autoresponder rules enabled and "Unmatched requests passthrough" option switched on. If left in this state for several hours an amount memory it uses could grow up to 10GB and even more which is quite annoying...

Autosave option is enabled and sessions are dumped every 5 minutes. So this behaviour is not because of session list is becoming large, it is being cleaned every 5 minutes.


Need More Info
Last Updated: 17 Feb 2021 09:31 by ADMIN

I've been trying to install the root certificate to decript https traffic with no results.

 

20:42:38:5197 Fiddler Running...
20:42:38:5202 Fiddler.Network.AutoProxy> AutoProxy Detection failed.
20:42:38:5202 AutoProxy failed. Disabling for this network.
20:42:38:5481 Windows 8+ AppContainer isolation feature detected.
20:42:44:4729 Assembly 'C:\Users\Mauro\AppData\Local\Programs\Fiddler\CertMaker.dll' was not found. Using default Certificate Generator.
20:42:44:4754 /Fiddler.CertMaker> Using .‰+˜ for certificate generation; UseWildcards=True.
20:42:46:0206 /Fiddler.CertMaker> Root Certificate located; private key in container '4f42d4e82d7f6c170e7a049cf6dfeeaa_8bf41fe8-e204-441e-8fc2-475cb85c8829'
20:42:48:8545 !Fiddler.CertMaker> Unable to auto-trust root: System.Security.Cryptography.CryptographicException: Access is denied.

   at System.Security.Cryptography.X509Certificates.X509Store.Add(X509Certificate2 certificate)
   at .‰.TrustRootCertificate() in C:\Jenkins\Fiddler_Windows\workspace\FiddlerCore\FiddlerCore.Shared\Common\Core\DefaultCertProvider.cs:line 965
Need More Info
Last Updated: 06 Dec 2020 06:31 by Eric

Hello dear fiddler support.

 

The bug i've found is: Fiddler doesn't support some encryption ciphers.

 

Recently I was trying to connect to https://inlat.am/ site with "Decrypt SSL traffic" option set in fiddler to my genuine surprise i couldn't even connect to site.

I am using chrome 87.0.4280.88 64bit  and fiddler v5.0.20204.45441 for .NET 4.6.1

Without  "Decrypt SSL traffic" option set in Fiddler - chrome works fine.

 

So i decided to investigate what actually happen.

I run to https://www.ssllabs.com/ site to check supported ciphers - here you can check it https://www.ssllabs.com/ssltest/analyze.html?d=inlat.am&s=18.159.255.107

and tried to reproduce the issue with wirshark  on.

 

In wire shark i can see that there is no ciphers supported by https://inlat.am/ site 

Cipher Suites (24 suites)
    Cipher Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 (0xc028)
    Cipher Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 (0xc027)
    Cipher Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (0xc014)
    Cipher Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA (0xc013)
    Cipher Suite: TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 (0x009f)
    Cipher Suite: TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 (0x009e)
    Cipher Suite: TLS_RSA_WITH_AES_256_GCM_SHA384 (0x009d)
    Cipher Suite: TLS_RSA_WITH_AES_128_GCM_SHA256 (0x009c)
    Cipher Suite: TLS_RSA_WITH_AES_256_CBC_SHA256 (0x003d)
    Cipher Suite: TLS_RSA_WITH_AES_128_CBC_SHA256 (0x003c)
    Cipher Suite: TLS_RSA_WITH_AES_256_CBC_SHA (0x0035)
    Cipher Suite: TLS_RSA_WITH_AES_128_CBC_SHA (0x002f)
    Cipher Suite: TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 (0xc02c)
    Cipher Suite: TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 (0xc02b)
    Cipher Suite: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 (0xc024)
    Cipher Suite: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 (0xc023)
    Cipher Suite: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA (0xc00a)
    Cipher Suite: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA (0xc009)
    Cipher Suite: TLS_DHE_DSS_WITH_AES_256_CBC_SHA256 (0x006a)
    Cipher Suite: TLS_DHE_DSS_WITH_AES_128_CBC_SHA256 (0x0040)
    Cipher Suite: TLS_DHE_DSS_WITH_AES_256_CBC_SHA (0x0038)
    Cipher Suite: TLS_DHE_DSS_WITH_AES_128_CBC_SHA (0x0032)
    Cipher Suite: TLS_RSA_WITH_3DES_EDE_CBC_SHA (0x000a)
    Cipher Suite: TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA (0x0013)

 

Now i now what the issue is about.

My question is how to fix the problem with ciphers.

In my opinion you should somehow add it in Fiddler.

 

 

 

 

Need More Info
Last Updated: 02 Nov 2020 13:02 by ADMIN

Hi,

I'm testing a website that has a self signed SSL cert. I can navigate to this URL via an extra warning step on chrome (see attached screen shot).

However via Fiddler, I just get an error that "this site cannot be reached" and I can see it's dropped on the Fiddler side: I can see the tunnel CONNECT request, but no subsequent request.

I've enabled the option "Ignore server certificate errors (unsafe)" and restarted Fiddler, but the problem still persists.

 

As always, thank you for your work on this.

Ronen

 

Need More Info
Last Updated: 05 Oct 2020 05:22 by ADMIN
Created by: S
Comments: 1
Type: Bug Report
0

When using Fiddler, there seems to be some bugs around resizing the GUI/UI, namely the dividers between sections such as between packet list vs. inspectors panes. It seems that when Fiddler is maximized full-screen, the divider (while using "Wide" layout) is shifted all the way up high, just beneath the initial packet in the list (Fiddler's update check).

I've been able to adjust the UI by manually manipulating Fiddler's registry settings, but even then it still seems finicky -- sometimes they take, sometimes they don't.

v5.0.20202.18177 for .NET 4.6.1
Built: Tuesday, April 14, 2020