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The title is a little bit unclear but I had no idea to describe the following issue in there.
I found a vulnerability in a website where I am able to bypass the CSRF protection (Bug Bounty program...). This website uses a csrf cookie and a csrf header. The only thing they do is to compare those 2 values on the server, if they are equal, the server will accept the request.
[...] X-CSRFToken: 12345 Referer: https://www.xxx.com Accept-Encoding: gzip, deflate Accept-Language: en-US,en;q=0.8 Cookie: csrftoken=12345;
The header "X-CSRFToken" and the cookie "csrftoken" are equal which means the request will be accepted by the server. This is quite bad because the whole sense of the csrf token is gone. I can choose the value of the token, it just has to be present in the request.
What I'm asking you guys is how to use this in a real world scenario? I can't add a custom header by using a XMLHTTPRequest because I am not SameOrigin.... The only thing I thought of is to find a XSS vulnerability but when I got that I would be able to read the CSRF token anyway...
How to add this Header to really use this kind of vulnerability?