What is CVE-2021-1867?

CVE-2021-1867 is a high-severity vulnerability in Apple iOS And Ipados, classified under Out-of-bounds Read. CVSS score: 8.8/10. Published 2021-09-08.

How severe is CVE-2021-1867?

High severity. CVSS v3 base score is 8.8 out of 10.

Out-of-bounds Read in Apple iOS And Ipados

CVE-2021-1867

An out-of-bounds read was addressed with improved input validation. This issue is fixed in iOS 14.5 and iPadOS 14.5, macOS Big Sur 11.3. A malicious application may be able to execute arbitrary code with kernel privileges.

Vulnerability class: Buffer Overflow

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

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.019 (78.4th percentile), scored 2026-10-02.

Low probability of exploitation in the next 30 days, but still tracked. 78th percentile — 78.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.019 · newest: 0.019 · change: 0.000

Affected products

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

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

References

support.apple.com/en-us/HT212317 (Vendor Advisory)
support.apple.com/en-us/HT212325 (Vendor Advisory)

Frequently asked questions

What is CVE-2021-1867?: CVE-2021-1867 is a high-severity vulnerability in Apple iOS And Ipados, classified under Out-of-bounds Read. CVSS score: 8.8/10. Published 2021-09-08.
How severe is CVE-2021-1867?: High severity. CVSS v3 base score is 8.8 out of 10.