CVE-2021-30780

Name: CVE-2021-30780
Creator: NVD / NIST
Published: 2021-09-08T14:15:11.003+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10EPSS 1.26%

Last modified Jun 17, 2026

CVE-2021-30780 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 14.7, macOS Big Sur 11.5, watchOS 7.6, tvOS 14.7, Security Update 2021-005 Mojave, Security Update 2021-004 Catalina. EPSS estimates a 1.26% chance of exploitation in the next 30 days.

Description

An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 14.7, macOS Big Sur 11.5, watchOS 7.6, tvOS 14.7, Security Update 2021-005 Mojave, Security Update 2021-004 Catalina. A malicious application may be able to gain root privileges.

Metrics

CVSS 3.1

7.8/10

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS Probability

1.26%

65.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-787

Affected Software

Vendor	Product	Versions
Apple	Iphone Os	< 14.7
Apple	Mac Os X	>= 10.14, <= 10.14.5
Apple	Mac Os X	>= 10.15, <= 10.15.6
Apple	Mac Os X	10.14.6
Apple	Mac Os X	10.15.7
Apple	Macos	>= 11.0, < 11.5
Apple	Tvos	< 14.7
Apple	Watchos	< 7.6

References

https://support.apple.com/en-us/HT212600Release Notes, Vendor Advisory
https://support.apple.com/en-us/HT212601Release Notes, Vendor Advisory
https://support.apple.com/en-us/HT212602Release Notes, Vendor Advisory
https://support.apple.com/en-us/HT212603Release Notes, Vendor Advisory
https://support.apple.com/en-us/HT212604Release Notes, Vendor Advisory
https://support.apple.com/en-us/HT212605Release Notes, Vendor Advisory
https://support.apple.com/en-us/HT212600Release Notes, Vendor Advisory
https://support.apple.com/en-us/HT212601Release Notes, Vendor Advisory
https://support.apple.com/en-us/HT212602Release Notes, Vendor Advisory
https://support.apple.com/en-us/HT212603Release Notes, Vendor Advisory
https://support.apple.com/en-us/HT212604Release Notes, Vendor Advisory
https://support.apple.com/en-us/HT212605Release Notes, Vendor Advisory

Timeline

Published: Sep 8, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-30780?

How severe is CVE-2021-30780?

CVE-2021-30780 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 1.26% probability of exploitation in the next 30 days.

How do I fix CVE-2021-30780?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-30780?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST