SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

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…

MEDIUM 5.9EPSS 1.81%

Does this matter?

Lower severity and a low EPSS score (1.81%). Track it; it rarely justifies an emergency change on its own.

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`.

CVSS 3.1
5.9 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS
1.81% probability · 77th percentile
CISA KEV
Not listed
Weakness
CWE-295
Affected
haxx/curl · debian/debian linux · fedoraproject/fedora · netapp/clustered data ontap · netapp/ontap antivirus connector · netapp/h300s firmware · netapp/h500s firmware · netapp/h700s firmware · netapp/h410s firmware · apple/macos
Source
support@hackerone.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.