CVE-2020-27911
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 · uneditedAn integer overflow was addressed through improved input validation. This issue is fixed in macOS Big Sur 11.0.1, watchOS 7.1, iOS 14.2 and iPadOS 14.2, iCloud for Windows 11.5, tvOS 14.2, iTunes 12.11 for Windows. A remote attacker may be able to cause unexpected application termination or arbitrary code execution.
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 confidenceInteger overflow vulnerability in Apple's core operating systems (macOS, watchOS, iOS, iPadOS, tvOS) and related software (iCloud for Windows, iTunes for Windows) that was addressed through improved input validation. A remote attacker could potentially cause application termination or achieve arbitrary code execution.
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< 11.5< 12.11< 14.2< 14.2>= 11.0, < 11.0.1< 14.2< 7.1CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/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 checksWork through these to decide whether this CVE applies to you.
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Check macOS versionOpen System Preferences > About or run 'sw_vers' in Terminal. Look for the version number (e.g., 11.0, 11.0.1, 11.1)Affected if Version is 11.0 (the exact version, not 11.0.1 or later)
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Check iOS versionOn the device go to Settings > General > About, or connect to Finder/iTunes and view device info. Look for iOS version numberAffected if Version is less than 14.2 (e.g., 14.1, 14.0, 13.x)
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Check iPadOS versionOn the iPad go to Settings > General > About, or connect to Finder/iTunes and view device info. Look for iPadOS version numberAffected if Version is less than 14.2 (e.g., 14.1, 14.0, 13.x)
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Check watchOS versionOn Apple Watch go to Settings > General > About, or on paired iPhone open Watch app and go to My Watch > About. Look for watchOS versionAffected if Version is less than 7.1 (e.g., 7.0, 6.x)
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Check tvOS versionOn Apple TV go to Settings > General > About. Look for tvOS version numberAffected if Version is less than 14.2 (e.g., 14.1, 14.0, 13.x)
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Check iCloud for Windows versionOpen Windows Control Panel > Programs and Features, find iCloud in the list, and check the version column. Alternatively open iCloud and look in Settings or AboutAffected if Version is less than 11.5
You are affected if any of your installed Apple software versions fall below the fixed version numbers listed above for your specific product.
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 data7.111.0.111.5
Apply vendor patches: macOS Big Sur 11.0.1 or later, watchOS 7.1 or later, iOS 14.2 or later, iPadOS 14.2 or later, tvOS 14.2 or later, iCloud for Windows 11.5 or later, iTunes 12.11 for Windows or later.
- Consultation2.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-27911 — 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-2020-27911 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