What is CVE-2021-30667?

CVE-2021-30667 is a medium-severity vulnerability in Apple iOS And Ipados, classified under Improper Authentication. CVSS score: 5.4/10. Published 2021-09-08.

How severe is CVE-2021-30667?

Medium severity. CVSS v3 base score is 5.4 out of 10.

Auth bypass in Apple iOS And Ipados

CVE-2021-30667

A logic issue was addressed with improved validation. This issue is fixed in iOS 14.6 and iPadOS 14.6. An attacker in WiFi range may be able to force a client to use a less secure authentication mechanism.

Vulnerability class: Broken Authentication

Published 2021-09-08 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (36.2th percentile), scored 2026-10-02.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 36.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Apple iOS And Ipados — versions unspecified
Apple Ipados
Apple Iphone OS

Weakness classification (CWE)

CWE-287 — Improper Authentication

References

support.apple.com/en-us/HT212528 (Release Notes, Vendor Advisory)

Frequently asked questions

What is CVE-2021-30667?: CVE-2021-30667 is a medium-severity vulnerability in Apple iOS And Ipados, classified under Improper Authentication. CVSS score: 5.4/10. Published 2021-09-08.
How severe is CVE-2021-30667?: Medium severity. CVSS v3 base score is 5.4 out of 10.