What is CVE-2021-1794?

CVE-2021-1794 is a critical-severity vulnerability in Apple iOS And Ipados, classified under Out-of-bounds Read. CVSS score: 9.8/10. Published 2021-04-02.

How severe is CVE-2021-1794?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Out-of-bounds Read in Apple iOS And Ipados

CVE-2021-1794

An out-of-bounds read was addressed with improved input validation. This issue is fixed in iOS 14.4 and iPadOS 14.4. A remote attacker may be able to cause arbitrary code execution.

Vulnerability class: Buffer Overflow

Published 2021-04-02 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.021 (81.4th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 81st percentile — 81.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.021 · newest: 0.021 · change: 0.000

Affected products

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

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

References

support.apple.com/en-us/HT212146 (Vendor Advisory)

Frequently asked questions

What is CVE-2021-1794?: CVE-2021-1794 is a critical-severity vulnerability in Apple iOS And Ipados, classified under Out-of-bounds Read. CVSS score: 9.8/10. Published 2021-04-02.
How severe is CVE-2021-1794?: Critical severity. CVSS v3 base score is 9.8 out of 10.