Mac Os XOperating system · Apple

CVE-2021-30922

HIGH · 7.8 CVSS v3.1 Published 2021-08-24
Fix available
A fix is available. Upgrade to 10.15.7 / 11.6.1 or later.
See remediation →
80/100
Remediation priority · High
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Multiple out-of-bounds write issues were addressed with improved bounds checking. This issue is fixed in macOS Big Sur 11.6.1. A malicious application may be able to execute arbitrary code with kernel privileges.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Kernel-level out-of-bounds write vulnerability in macOS Big Sur allowing a malicious local application to execute arbitrary code with kernel privileges. The issue was addressed with improved bounds checking in the 11.6.1 update.

MitigationApply macOS Big Sur 11.6.1 or later security update to eliminate the vulnerability. Organizations should inventory all macOS systems, identify those below 11.6.1, and deploy the patch accordingly.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Mac Os XOperating system
Affected:>= 10.15, < 10.15.7= 10.15.7
macOSOperating system
Affected:< 11.6.1= 12.0.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed macOS version via System Preferences
    Click Apple menu > About This Mac. The version number is displayed under the macOS name (for example, 11.6 or 12.0.0).
    Affected if Version shows 10.15.7, or any version from 11.0 to 11.6.0, or exactly 12.0.0
  2. Check macOS build number for precise version identification
    Open Terminal and run: sw_vers -buildVersion. Compare the build number against Apple's release notes for 11.6.1.
    Affected if Build version is earlier than the 11.6.1 security update build, or the system has not received the 11.6.1 patch.
  3. Verify if the kernel has been patched via system_profiler
    Run: system_profiler SPSoftwareDataType | grep 'System Version' to retrieve detailed version and build information.
    Affected if System reports version < 11.6.1 or build number indicates pre-patch state.

A system is affected if it is running macOS 10.15.7, any macOS 11.x version prior to 11.6.1, or exactly version 12.0.0.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 10.15.7 / 11.6.1 or later
Fixed in 10.15.711.6.1
Interim mitigation

Apply macOS Big Sur 11.6.1 or later security update to eliminate the vulnerability. Organizations should inventory all macOS systems, identify those below 11.6.1, and deploy the patch accordingly.

Recommended fix High confidence

macOS Big Sur 11.6.1 or later; Security Update 2021-005 for macOS Catalina 10.15.7; macOS Monterey 12.1 or later for macOS 12.0.0

  1. Back up your Mac using Time Machine or another backup solution before updating
  2. Open System Preferences (System Settings on macOS 13+) and navigate to Software Update
  3. Click 'Check for Update' or ensure automatic updates are enabled
  4. Install macOS Big Sur 11.6.1 or later (or Security Update 2021-005 for macOS Catalina 10.15.7)
  5. Restart your Mac when prompted to complete the update
  6. Verify the update was successful by checking System Information > Software > macOS version
Caveat Standard macOS update risks apply - ensure full backup before proceeding; some legacy applications may not be compatible with newer macOS versions

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Mac Os X Scoped from the published advisory
  • Consultation4.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,120
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Scan for this in your stack

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dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-30922 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data