What is CVE-2021-30753?

CVE-2021-30753 is a medium-severity vulnerability in Apple iOS And Ipados, classified under Out-of-bounds Read. CVSS score: 5.5/10. Published 2021-09-08.

How severe is CVE-2021-30753?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Out-of-bounds Read in Apple iOS And Ipados

CVE-2021-30753

Processing a maliciously crafted font may result in the disclosure of process memory. This issue is fixed in macOS Big Sur 11.4, tvOS 14.6, watchOS 7.5, iOS 14.6 and iPadOS 14.6. An out-of-bounds read was addressed with improved input validation.

Vulnerability class: Buffer Overflow

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

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.009 (58.6th percentile), scored 2026-10-02.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 59th percentile — 58.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

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

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

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-2021-30753?: CVE-2021-30753 is a medium-severity vulnerability in Apple iOS And Ipados, classified under Out-of-bounds Read. CVSS score: 5.5/10. Published 2021-09-08.
How severe is CVE-2021-30753?: Medium severity. CVSS v3 base score is 5.5 out of 10.