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I tried to get reflected XSS in vulnerable website with a request to the following URL:

https://vulnerable.website/dir/dir?param1=test"><svg/onload=alert(1)>

The browser URL encode the chars and it is also reflected back in the response encoded, so it doesn't work. But if I intercept the request and type the payload without encoding the XSS is executed.

Is there any way to send the request without the browser encoding it?

  • 1
    afaik, the browser will encode urls for you, from URL bar, ajax, and hrefs – dandavis Jan 26 '18 at 19:50
  • IE and Edge do not encode; other browsers do. – paj28 Jan 26 '18 at 20:23
  • @paj28 Edge also encodes it (just tested), and i can't image IE wouldn't. One point of confusion might be that Edge's human-facing reporting of the URL is NOT escaped (ex: dev tools, url bar), but the actual request (seen in HTTP logs) is escaped like Chrome. – dandavis Jan 26 '18 at 20:31
  • @dandavis - My bad it is IE only and Edge does escape. I tested again just now. – paj28 Jan 26 '18 at 20:47
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It depends on the browser you are using.

Here is a blog post from Troy Hunt regarding this topic:

You can try to intercept the request using tools like Burp Suite. If you intercept the request, you can try to change the encoding character set and check if the desired result occurs.

  • I believe your link to the blog post is wrong. – Johannes Kuhn Jan 26 '18 at 20:00
  • @JohannesKuhn the link is correct – paj28 Jan 26 '18 at 20:06
  • @paj28: Yes, I changed it. He was right. :) – Kevin Gomez Buquerin Jan 26 '18 at 20:07
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    OP already said they can manually intercept the request and change the parameter. But that doesn't make it an exploitable XSS flaw which is what OP is asking. Also, if you link a post it's always helpful to include the gist in your answer, too. (Also note that the linked post is from 2012 and browser behavior changes a lot.) – Arminius Jan 26 '18 at 20:09
  • Hi guys , thanks for your responses it worked in IE only because IE didn't encode the URL , i tested it – Tarek Zidan Jan 27 '18 at 20:49

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