curl and libcurl 7.27.0 through 7.35.0, when running on Windows and using the SChannel/Winssl TLS backend, does not verify that the server hostname matches a domain name in the subject's Common Name (CN) or subjectAltName field of the X.509 certificate when accessing a URL that uses a numerical IP address, which allows man-in-the-middle attackers to spoof servers via an arbitrary valid certificate.
| Product | Vendor | Version |
|---|---|---|
| n/a | n/a | <= 4.9.* |