CVE-2021-1786
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 · uneditedA logic issue was addressed with improved state management. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, watchOS 7.3, tvOS 14.4, iOS 14.4 and iPadOS 14.4. A local user may be able to create or modify system files.
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 confidenceA logic flaw in state management within Apple's operating systems allowed a local authenticated user to bypass intended access controls and create or modify system files. This represents a privilege escalation vulnerability where the application failed to properly validate or enforce authorization state before file system operations.
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< 14.4< 14.4>= 10.14, < 10.14.6>= 10.15, < 10.15.7= 10.14.6= 10.15.7>= 11.0, < 11.2< 14.4< 7.3CVSS 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
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/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 macOS version on Mac computersOpen Terminal and run: sw_vers -productVersionAffected if Version is 10.14.x, 10.15.x, or 11.0.x through 11.1.x (versions below 10.14.6, 10.15.7, or 11.2)
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Check iOS version on iPhoneGo to Settings > General > About and note the version number, or run: idevicesyslog (requires macOS with Xcode)Affected if Version is below 14.4 (for example, 14.3, 14.2, etc.)
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Check iPadOS version on iPadGo to Settings > General > About and note the version numberAffected if Version is below 14.4
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Check tvOS version on Apple TVGo to Settings > General > About > VersionAffected if Version is below 14.4
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Check watchOS version on Apple WatchOpen the Watch app on paired iPhone, go to General > About, or check on Apple Watch at Settings > General > AboutAffected if Version is below 7.3
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Assess multi-user environment exposureDetermine if the system has multiple user accounts, especially untrusted or guest users, by checking System Preferences > Users & Groups (or System Settings > Users on macOS 11+)Affected if System has multiple local users and runs an affected OS version listed above
You are affected if your device runs any version lower than iOS/iPadOS 14.4, macOS 10.14.6/10.15.7/11.2, tvOS 14.4, or watchOS 7.3, especially in multi-user configurations.
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.
From vendor data7.310.14.610.15.7
Apply the vendor-supplied security updates: macOS Big Sur 11.2 or later, Security Update 2021-001 for Catalina/Mojave, watchOS 7.3, tvOS 14.4, iOS 14.4, or iPadOS 14.4. Prioritize systems with untrusted local users or multi-user configurations.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-1786 — 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-2021-1786 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