CVE-2021-30853
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 · uneditedThis issue was addressed with improved checks. This issue is fixed in macOS Big Sur 11.6. A malicious application may bypass Gatekeeper checks.
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 confidenceCVE-2021-30853 is a Gatekeeper bypass vulnerability in macOS Big Sur. A malicious application could circumvent Gatekeeper's security checks, which normally restrict execution to trusted applications from the App Store or identified developers. The fix in macOS Big Sur 11.6 implemented improved validation checks to prevent this bypass.
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< 11.6CVSS 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
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
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 checksWork through these to decide whether this CVE applies to you.
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Check the installed macOS versionOpen Terminal and run: sw_vers -productVersionAffected if The version is 11.x (Big Sur) and is lower than 11.6, or the version is earlier than Big Sur 11.x and you rely on Gatekeeper for application execution controls
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Confirm macOS Big Sur release numberRun: uname -r to get the kernel release, or check System Preferences > About > macOS for the full version number (e.g., 11.5.1)Affected if The version shows 11.0 through 11.5.x (any Big Sur version prior to 11.6)
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Verify Gatekeeper is enabledRun: spctl --status in Terminal. Look for 'enabled' in the outputAffected if Gatekeeper is disabled and the macOS version is below 11.6, exposing the system to the bypass vulnerability
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Check Gatekeeper assessment statusRun: spctl --master-status to see global assessment settingsAffected if The system shows assessment is disabled or in a non-enforcing state while running a vulnerable macOS version
You are affected if your Mac runs macOS Big Sur version 11.0 through 11.5.x, as these versions contain the Gatekeeper bypass vulnerability fixed in macOS 11.6.
Generated from the published advisory. Verify against your own configuration.
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 · scoped11.6
Apply macOS Big Sur 11.6 or later security updates to ensure Gatekeeper protection is fully enforced and cannot be bypassed by malicious applications.
macOS Big Sur 11.6
- Back up all important data on the affected Mac using Time Machine or another backup solution
- Verify the current macOS version by clicking the Apple menu and selecting About This Mac
- Open the App Store and search for 'macOS Big Sur 11.6' or go to System Preferences > Software Update
- Download and install the macOS Big Sur 11.6 update
- Restart the Mac when prompted to complete the installation
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,744.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-30853 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-30853 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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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.
- 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