CVE-2023-28321
curl - security update
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`.
How to fix CVE-2023-28321
To remediate CVE-2023-28321, upgrade the affected package to a fixed version below.
- —upgrade to 8.1.0-r0 or later
- —upgrade to 7.74.0-1.3+deb11u9 or later
- —upgrade to 7.64.0-4+deb10u7 or later
Is CVE-2023-28321 being exploited?
Low — EPSS is 0.3%, meaning exploitation activity has not been observed at scale.
Affected packages (3)
- from 0, < 8.1.0-r0
- from 0, < 7.74.0-1.3+deb11u9
- from 0, < 7.64.0-4+deb10u7
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N |