This website has a header in the request (If-None-Match) and whatever you set the value to for it, the response will contain a header (ETag) with the value of the If-None-Match header.
I understand why it does that, but is there any possible exploit that could be performed with this reflection of a header value from request to response?
I attempted CRLF and it failed since the response header didn't decode URL encoding or Unicode entities in the request.