dbcve.org
macOSOperating system · Apple

CVE-2021-1853

HIGH · 7.8 CVSS v3.1 Published 2021-09-08
Fix available
A fix is available. Upgrade to 11.3 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
A logic issue was addressed with improved state management. This issue is fixed in macOS Big Sur 11.3. A local attacker may be able to elevate their 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 · moderate confidence

A logic issue in macOS Big Sur's state management allows a local authenticated attacker to elevate their privileges to root or higher by exploiting improper handling of certain state conditions.

MitigationApply the macOS Big Sur 11.3 or later security update, which addresses the state management logic flaw to prevent local privilege escalation.

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
macOSOperating system
Affected:>= 11.0, < 11.3

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 Big Sur version
    Run `sw_vers -productVersion` in Terminal, or go to Apple menu > About This Mac to view the version number
    Affected if Version is 11.0, 11.1, or any 11.2.x release (anything >= 11.0 but < 11.3)
  2. Confirm Big Sur release number
    If the version shows 11.x, run `sw_vers -buildVersion` to see the specific build (e.g., 20D74, 20D91, etc.)
    Affected if Build corresponds to an unpatched Big Sur 11.0-11.2 release

If macOS Big Sur version is 11.0, 11.1, or any 11.2.x release, the system is vulnerable to local privilege escalation via the state management flaw.

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 11.3 or later
Fixed in 11.3
Interim mitigation

Apply the macOS Big Sur 11.3 or later security update, which addresses the state management logic flaw to prevent local privilege escalation.

Recommended fix High confidence

macOS Big Sur 11.3 or later

  1. Back up important data before initiating the system update
  2. Check the current macOS version by clicking the Apple menu and selecting 'About This Mac'
  3. Open System Preferences and click 'Software Update' to check for available updates
  4. Install macOS Big Sur 11.3 or later via the Software Update mechanism
  5. Alternatively, download macOS 11.3 directly from Apple and run the installer to perform a clean install or upgrade
  6. Restart the system after the update completes to ensure all security patches are fully applied
Caveat Standard upgrade considerations apply - ensure compatibility with existing applications and back up data before updating

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

Fix this in macOS Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,040
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,664.

Scan for this in your stack

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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-2021-1853 in production — separate from our analysis above.

No notes yet

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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