CVE-2023-28321

Name	CVE-2023-28321
Description	An improper certificate validation vulnerability exists in curl <v8.1.0 in the way it supports matching of wildcard patterns when listed as "Subject Alternative Name" in TLS server certificates. curl can be built to use its own name matching function for TLS rather than one provided by a TLS library. This private wildcard matching function would match IDN (International Domain Name) hosts incorrectly and could as a result accept patterns that otherwise should mismatch. IDN hostnames are converted to puny code before used for certificate checks. Puny coded names always start with `xn--` and should not be allowed to pattern match, but the wildcard check in curl could still check for `x*`, which would match even though the IDN name most likely contained nothing even resembling an `x`.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DLA-3613-1
Debian Bugs	1036239

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
curl (PTS)	bullseye	7.74.0-1.3+deb11u13	fixed
	bullseye (security)	7.74.0-1.3+deb11u14	fixed
	bookworm	7.88.1-10+deb12u12	fixed
	bookworm (security)	7.88.1-10+deb12u5	fixed
	sid, trixie	8.13.0-5	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Origin	Debian Bugs
curl	source	buster	7.64.0-4+deb10u7	DLA-3613-1
curl	source	bullseye	7.74.0-1.3+deb11u9
curl	source	(unstable)	7.88.1-10		1036239

Notes

https://curl.se/docs/CVE-2023-28321.html
Introduced by: https://github.com/curl/curl/commit/9631fa740708b1890197fad01e25b34b7e8eb80e (curl-7_12_0)
Fixed by: https://github.com/curl/curl/commit/199f2d440d8659b42670c1b796220792b01a97bf (curl-8_1_0)