dbcve.org
IcloudApplication · Apple

CVE-2021-1811

MEDIUM · 6.5 CVSS v3.1 Published 2021-09-08
Fix available
A fix is available. Upgrade to 7.4 / 11.3 or later.
See remediation →
72/100
Remediation priority · Elevated
Remotely reachable No privileges

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 iTunes 12.11.3 for Windows, Security Update 2021-002 Catalina, Security Update 2021-003 Mojave, iCloud for Windows 12.3, macOS Big Sur 11.3, watchOS 7.4, tvOS 14.5, iOS 14.5 and iPadOS 14.5. Processing a maliciously crafted font may result in the disclosure of process memory.

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

A logic vulnerability in font processing allows a maliciously crafted font file to disclose process memory due to improper state management during parsing. The flaw enables an attacker to potentially read sensitive data from the application's memory space by tricking a user into opening a specially crafted font file.

MitigationApply vendor security updates: iOS 14.5/iPadOS 14.5, macOS Big Sur 11.3/Security Update 2021-002/2021-003, watchOS 7.4, tvOS 14.5, iTunes 12.11.3 for Windows, and iCloud for Windows 12.3.

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
IcloudApplication
Affected:< 12.3
ItunesApplication
Affected:< 12.11.3
IpadosOperating system
Affected:< 14.5
Iphone OsOperating system
Affected:< 14.5
Mac Os XOperating system
Affected:>= 10.14, <= 10.14.5>= 10.15, <= 10.15.5= 10.14.6= 10.15.6= 10.15.7
macOSOperating system
Affected:>= 11.0, < 11.3
TvosOperating system
Affected:< 14.5
WatchosOperating system
Affected:< 7.4

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
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

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

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

  1. Check macOS version
    Open System Preferences > About This Mac, or run 'sw_vers' in Terminal, or run 'system_profiler SPSoftwareDataType'
    Affected if Version is 10.14.x and <= 10.14.6, or 10.15.x and <= 10.15.7, or >= 11.0 and < 11.3
  2. Check iOS or iPadOS version
    Go to Settings > General > About on the device
    Affected if Version is less than 14.5
  3. Check watchOS version
    Go to Settings > General > About on the Apple Watch, or open the Watch app on iPhone and check About
    Affected if Version is less than 7.4
  4. Check tvOS version
    Go to Settings > General > About on Apple TV
    Affected if Version is less than 14.5
  5. Check iTunes for Windows version
    Open iTunes > Help > About iTunes, or check Programs and Features in Control Panel
    Affected if Version is less than 12.11.3
  6. Check iCloud for Windows version
    Open iCloud > General > About iCloud, or check Programs and Features in Control Panel
    Affected if Version is less than 12.3

You are affected if any Apple product listed above is installed and its version falls within the specified vulnerable ranges; the flaw requires a user to open a maliciously crafted font file to trigger memory disclosure.

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 7.4 / 11.3 / 12.3 or later
Fixed in 7.411.312.3
Interim mitigation

Apply vendor security updates: iOS 14.5/iPadOS 14.5, macOS Big Sur 11.3/Security Update 2021-002/2021-003, watchOS 7.4, tvOS 14.5, iTunes 12.11.3 for Windows, and iCloud for Windows 12.3.

Recommended fix High confidence

iOS 14.5 / iPadOS 14.5 / macOS 11.3 / tvOS 14.5 / watchOS 7.4 / iTunes 12.11.3 (Windows) / iCloud 12.3 (Windows) / Security Update 2021-002/2021-003

  1. Identify your Apple device and current OS version
  2. For iOS/iPadOS devices: Go to Settings > General > Software Update and upgrade to iOS 14.5/iPadOS 14.5 or later
  3. For macOS Big Sur (11.x) users: Go to System Preferences > Software Update and upgrade to macOS 11.3 or later
  4. For macOS Catalina users: Apply Security Update 2021-002 Catalina (go to System Preferences > Software Update)
  5. For macOS Mojave users: Apply Security Update 2021-003 Mojave (go to System Preferences > Software Update)
  6. For Windows iTunes users: Upgrade to iTunes 12.11.3 for Windows
  7. For iCloud for Windows users: Upgrade to iCloud for Windows 12.3
  8. For tvOS users: Go to Settings > System > Software Update and upgrade to tvOS 14.5 or later

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

Fix this in Icloud Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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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-2021-1811 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