What is CVE-2021-30771?

CVE-2021-30771 is a high-severity vulnerability in Apple iOS And Ipados, classified under Out-of-bounds Write. CVSS score: 7.8/10. Published 2022-03-18.

How severe is CVE-2021-30771?

High severity. CVSS v3 base score is 7.8 out of 10.

Buffer overflow in Apple iOS And Ipados

CVE-2021-30771

An out-of-bounds write was addressed with improved input validation. This issue is fixed in macOS Big Sur 11.4, iOS 14.6 and iPadOS 14.6, watchOS 7.5, tvOS 14.6. Processing a maliciously crafted font file may lead to arbitrary code execution.

Vulnerability class: Buffer Overflow

Published 2022-03-18 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.013 (70.5th percentile), scored 2026-10-03.

Low probability of exploitation in the next 30 days, but still tracked. 70th percentile — 70.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.013 · newest: 0.013 · change: 0.000

Affected products

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

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

support.apple.com/en-us/HT212528 (Vendor Advisory)
support.apple.com/en-us/HT212529 (Vendor Advisory)
support.apple.com/en-us/HT212532 (Vendor Advisory)
support.apple.com/en-us/HT212533 (Vendor Advisory)

Frequently asked questions

What is CVE-2021-30771?: CVE-2021-30771 is a high-severity vulnerability in Apple iOS And Ipados, classified under Out-of-bounds Write. CVSS score: 7.8/10. Published 2022-03-18.
How severe is CVE-2021-30771?: High severity. CVSS v3 base score is 7.8 out of 10.