Vulnerability in Apple macOS
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`.
Vulnerability class: Improper Certificate Validation
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.018 (77.8th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 78th percentile — 77.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.018 · newest: 0.018 · change: 0.000
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- hackerone.com/reports/1950627 (Exploit, Patch, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- security.netapp.com/advisory/ntap-20230609-0009/ (Third Party Advisory)
- support.apple.com/kb/HT213843 (Third Party Advisory)
- support.apple.com/kb/HT213844 (Third Party Advisory)
- support.apple.com/kb/HT213845 (Third Party Advisory)
- seclists.org/fulldisclosure/2023/Jul/52 (mailing-list, Mailing List, Third Party Advisory)
- seclists.org/fulldisclosure/2023/Jul/48 (mailing-list, Mailing List, Third Party Advisory)
- seclists.org/fulldisclosure/2023/Jul/47 (mailing-list, Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2023-28321?
- CVE-2023-28321 is a medium-severity vulnerability in Apple macOS, classified under Improper Certificate Validation. CVSS score: 5.9/10. Published 2023-05-26.
- How severe is CVE-2023-28321?
- Medium severity. CVSS v3 base score is 5.9 out of 10.
- Is CVE-2023-28321 known to be exploited?
- 4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.