Subject: curl is vulnerable to CVE-2021-22890 and CVE-2021-22876

From: Léo Le Bouter <[email-masked]>
Date: Fri, 02 Apr 2021 16:04:31 +0200

CVE-2021-22890	01.04.21 20:15
curl 7.63.0 to and including 7.75.0 includes vulnerability that allows
a malicious HTTPS proxy to MITM a connection due to bad handling of TLS
1.3 session tickets. When using a HTTPS proxy and TLS 1.3, libcurl can
confuse session tickets arriving from the HTTPS proxy but work as if
they arrived from the remote server and then wrongly "short-cut" the
host handshake. When confusing the tickets, a HTTPS proxy can trick
libcurl to use the wrong session ticket resume for the host and thereby
circumvent the server TLS certificate check and make a MITM attack to
be possible to perform unnoticed. Note that such a malicious HTTPS
proxy needs to provide a certificate that curl will accept for the
MITMed server for an attack to work - unless curl has been told to
ignore the server certificate check.

CVE-2021-22876	01.04.21 20:15
curl 7.1.1 to and including 7.75.0 is vulnerable to an "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.

A WIP patch will follow, please help finishing it (rebase curl-CVE-
2021-22890.patch on 7.74.0).