CVE-2023-28321

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`.

Affected products

Alt Linux, Almalinux, Astra Linux, Centos, Linuxmint, Apple Macos, Red Hat, Red Os

Haxx Curl

< 8.1.0

Fix

Available

CVSS 3.1

5.9 MEDIUM

EPSS

1.8% (76th percentile)

Weakness

CWE-295

NVD status

Modified

Published

2023-05-26

No exploit for CVE-2023-28321 has been indexed yet. Our index is built from live traffic and upstream syncs, so this page can only say what it knows — not that no exploit exists.