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, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub advisories/code/issues, web search, more)
Debian Bugs	1036239

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
curl (PTS)	buster	7.64.0-4+deb10u2	vulnerable
	buster (security)	7.64.0-4+deb10u6	vulnerable
	bullseye (security), bullseye	7.74.0-1.3+deb11u7	vulnerable
	bookworm	7.88.1-9	vulnerable
	sid	7.88.1-10	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
curl	source	(unstable)	7.88.1-10			1036239

Notes

[bullseye] - curl <no-dsa> (Minor issue)
[buster] - curl <no-dsa> (Minor issue)
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)