Tampering Client Requests and Server Responses with Fiddler
Why Stack Overflow recommends it
Stack Overflow users link it when answering how to modify or tamper with HTTP requests and responses in Fiddler, since it walks through the breakpoint workflow step by step.
Recommended by 3 people across 4 different months, 2013 to 2015.
What it is
A short Telerik tutorial showing how to use Fiddler to intercept web sessions and edit them. It demonstrates setting breakpoints so a request or response is paused and can be altered before it continues.
What people said
Recommends EricLaw · 2013-05 · Stack Overflow · on “Tamper GET request parameter with Tamper Data in Firefox?”
You can easily use Fiddler to tamper with any aspect of a request or response. You can do this using FiddlerScript or manually using breakpoints. To change traffic manually using breakpoints, watch this tutorial video: [this video]
Recommends EricLaw · 2013-07 · Stack Overflow · on “Fiddler: Modifying request sent”
This video: [this video] shows how to tamper requests in general. Generally speaking, File Upload forms in browsers carry the Content-Type within a multipart form body, so the "header" isn't in the HEADERS tab, it's in the TextView tab which shows the body. Having said that, what "vulnerability" do you expect you'll find? (Hint: You could probably even do what you're asking without even using Fiddler, simply rename a .JPG file to .TXT)
Recommends Mike Robinet · 2014-08 · Stack Overflow · on “maniplate html sent from server”
Yes. There are many ways. HTTP proxies such as Fiddler [LINK] or Burp [LINK] can break on all requests and then manipulate the response before it reaches the browser. Video explaining how this is done in Fiddler. [this video] There are also several browser plugins like Tampermonkey [LINK] (Chrome) and Greasemonkey [LINK] (Firefox) that allow you to execute custom JavaScript on page load automatically.
Recommends Justin · 2015-02 · Stack Overflow · on “How to modify a request in Fiddler?”
Ok, posting the answer that I put together from piecing it together from the following youtube video: Tampering Client Requests and Server Responses with Fiddler [this video] Start fiddler (I'm using Fiddler 4) You will notice that it intercepts all traffic through all browsers and other applications Set a filter - this will enable you to view only the data you are interested in On the right hand side, click on the filters tab Check 'Use Filters' On Hosts, use 'Show only the following Hosts' In the text box below that, put the host you are testing for. In our case for the test environment, put the following: testing.internalsite.com; In the section called 'Breakpoints', check 'Break request on PO