Response to TRACE http method - trace

Question

So I was testing my website and I tried connecting with the TRACE http method. In response I got a massive string. I don't know what it is. Does anybody know what could it be and if it's some sort of vulnerability?
This is the string I'm talking about:
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

Answer 1

It's a Base64 encoded string. Decoded it looks like this:
TRACE /.htpasswd HTTP/1.1
Host: www.ssfkz.si
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Firefox/91.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Connection: keep-alive
Cookie: jsCookieWarningCheck=declined
Upgrade-Insecure-Requests: 1
Cache-Control: max-age=0, no-cache
Origin: http://www.ssfkz.si
Pragma: no-cache
Which per se does not really look like a security flaw and much rather like a basic implementation of the TRACE http method which states that the contents of the request shall be reflected in their entirety in the response body.
Interesting note though, looking at the specification:
A client MUST NOT generate header fields in a TRACE request containing sensitive data that might be disclosed by the response. For example, it would be foolish for a user agent to send stored user credentials [RFC7235] or cookies [RFC6265] in a TRACE request. The final recipient of the request SHOULD exclude any request header fields that are likely to contain sensitive data when that recipient generates the response body.
So ideally the response should not have contained the Cookie header (to fully comply with the specification by my understanding the client you used to send the requests should not have included them in the first place however).