Previously, Node.js incorrectly accepted uniformResourceIdentifier (URI)
subject alternative names in checkServerIdentity regardless of the
application protocol. This was incorrect even in the most common cases.
For example, RFC 2818 specifies (and RFC 6125 confirms) that HTTP over
TLS only uses dNSName and iPAddress subject alternative names, but not
uniformResourceIdentifier subject alternative names.
Additionally, name constrained certificate authorities might not be
constrained to specific URIs, allowing them to issue certificates for
URIs that specify hosts that they would not be allowed to issue dNSName
certificates for.
Even for application protocols that make use of URI subject alternative
names (such as SIP, see RFC 5922), Node.js did not implement the
required checks correctly, for example, because checkServerIdentity
ignores the URI scheme.
As a side effect, this also fixes an edge case. When a hostname is not
an IP address and no dNSName subject alternative name exists, the
subject's Common Name should be considered even when an iPAddress
subject alternative name exists.
It remains possible for users to pass a custom checkServerIdentity
function to the TLS implementation in order to implement custom identity
verification logic.
This addresses CVE-2021-44531.
Co-authored-by: Akshay K <iit.akshay@gmail.com>
CVE-ID: CVE-2021-44531
Backport-PR-URL: https://github.com/nodejs-private/node-private/pull/303
PR-URL: https://github.com/nodejs-private/node-private/pull/300
Reviewed-By: Michael Dawson <midawson@redhat.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
