The issue is related to the exposure of private personal information to an unauthorized actor by leaking credentials in the HTTP Referer: header. libcurl does not strip off user credentials from the URL when automatically populating the `Referer:` HTTP request header field in outgoing HTTP requests, and therefore risks leaking sensitive data to the server that is the target of the second HTTP request. This can be exploited by a remote attacker to gain access to confidential data.