CVE-2021-1834

Name: CVE-2021-1834
Creator: NVD / NIST
Published: 2021-09-08T15:15:10.563+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 2.88%

Last modified Jun 17, 2026

CVE-2021-1834 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in macOS Big Sur 11.3, Security Update 2021-002 Catalina, Security Update 2021-003 Mojave. EPSS estimates a 2.88% 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 macOS Big Sur 11.3, Security Update 2021-002 Catalina, Security Update 2021-003 Mojave. A malicious application may be able to execute arbitrary code with kernel privileges.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

2.88%

85.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-787

Affected Software

Vendor	Product	Versions
Apple	Mac Os X	10.14
Apple	Mac Os X	10.14.0
Apple	Mac Os X	10.14.1
Apple	Mac Os X	10.14.2
Apple	Mac Os X	10.14.3
Apple	Mac Os X	10.14.4
Apple	Mac Os X	10.14.5
Apple	Mac Os X	10.14.6
Apple	Mac Os X	10.15
Apple	Mac Os X	10.15.1
Apple	Mac Os X	10.15.2
Apple	Mac Os X	10.15.3
Apple	Mac Os X	10.15.4
Apple	Mac Os X	10.15.5
Apple	Mac Os X	10.15.6
Apple	Mac Os X	10.15.7
Apple	Macos	>= 11.0, < 11.3

References

https://support.apple.com/en-us/HT212325Vendor Advisory
https://support.apple.com/en-us/HT212326Vendor Advisory
https://support.apple.com/en-us/HT212327Vendor Advisory
https://support.apple.com/en-us/HT212325Vendor Advisory
https://support.apple.com/en-us/HT212326Vendor Advisory
https://support.apple.com/en-us/HT212327Vendor Advisory

Timeline

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

Frequently Asked Questions

What is CVE-2021-1834?

How severe is CVE-2021-1834?

CVE-2021-1834 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 2.88% probability of exploitation in the next 30 days.

How do I fix CVE-2021-1834?

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-2021-1834?

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

Scan your code now

Source: NVD / NIST