CVE-2021-30821

Kernel code execution via IOGraphics memory corruption

Published Oct 28, 2021 · Updated Aug 3, 2024

IOGraphics memory corruption in affected Apple macOS releases allows local users to execute kernel code via a malicious application. Apple identifies improper memory handling in IOGraphics but has not published the affected code path, memory-safety operation, or triggering input. A malicious application must run locally on an affected Mac; successful corruption grants kernel-level code execution on Catalina before Security Update 2021-007, Big Sur before 11.6.1, and Monterey before 12.0.1.

CVSS severity7.8
High
EPSS probability1.07%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

IOGraphics memory corruption in affected Apple macOS releases allows local users to execute kernel code via a malicious application. Apple identifies improper memory handling in IOGraphics but has not published the affected code path, memory-safety operation, or triggering input. A malicious application must run locally on an affected Mac; successful corruption grants kernel-level code execution on Catalina before Security Update 2021-007, Big Sur before 11.6.1, and Monterey before 12.0.1.

The record

CVE
CVE-2021-30821
Published
Oct 28, 2021
Updated
Aug 3, 2024
Vendor
Apple
Product
macOS
Classifications
T1068
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 28, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <11.6
  2. Affected versionversion=unspecified <12.0
  3. Affected versionversion=unspecified <2021

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Apple · macOSversion=unspecified <11.6; version=unspecified <12.0; version=unspecified <2021

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
9.3NIST NVDAV:N/AC:M/Au:N/C:C/I:C/A:C

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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