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Actively exploited in the wild. This CVE is on the CISA Known Exploited Vulnerabilities list — treat remediation as urgent. Federal remediation due by 3 May 2022.
IpadosOperating system · Apple

CVE-2020-27930

HIGH · 7.8 CVSS v3.1 Published 2020-12-08
Fix available
A fix is available. Upgrade to 5.3.9 / 6.2.9 or later.
See remediation →
97/100
Remediation priority · Urgent
In the wild Public exploit 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 memory corruption issue was addressed with improved input validation. This issue is fixed in macOS Big Sur 11.0.1, watchOS 7.1, iOS 12.4.9, watchOS 6.2.9, Security Update 2020-006 High Sierra, Security Update 2020-006 Mojave, iOS 14.2 and iPadOS 14.2, watchOS 5.3.9, macOS Catalina 10.15.7 Supplemental Update, macOS Catalina 10.15.7 Update. Processing a maliciously crafted font may lead to 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 · high confidence

A memory corruption vulnerability in font processing allows arbitrary code execution when processing a maliciously crafted font file. The issue was addressed through improved input validation in the affected Apple operating systems.

MitigationApply the relevant security updates (iOS 12.4.9/14.2, iPadOS 14.2, watchOS 5.3.9/6.2.9/7.1, macOS High Sierra/Mojave/Catalina/Big Sur 11.0.1 updates) to all affected devices to remediate the vulnerability.

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
IpadosOperating system
Affected:< 14.2
Iphone OsOperating system
Affected:< 12.4.9>= 14.0, < 14.2
Mac Os XOperating system
Affected:< 10.15.7
macOSOperating system
Affected:>= 11.0, < 11.0.1
WatchosOperating system
Affected:< 5.3.9>= 6.0, < 6.2.9>= 7.0, < 7.1

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
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 checks

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

  1. Identify the installed macOS version
    Click the Apple menu, select 'About This Mac', and note the version number under 'macOS'
    Affected if The version is earlier than 10.15.7, or falls between 11.0 and 11.0.1 inclusive
  2. Identify the installed iOS or iPadOS version
    Go to Settings > General > About on the device and note the version number
    Affected if The version is earlier than 12.4.9, or falls between 14.0 and 14.2 (excluding 14.2)
  3. Identify the installed watchOS version
    Open the Watch app on the paired iPhone, go to General > About, and note the watchOS version
    Affected if The version is earlier than 5.3.9, or falls between 6.0 and 6.2.9 (excluding 6.2.9), or falls between 7.0 and 7.1 (excluding 7.1)
  4. Confirm font processing is in use
    The vulnerability is triggered when the system processes a maliciously crafted font file; no specific configuration check is needed as font parsing is a core system component
    Affected if The system processes an untrusted font file from an unknown or untrusted source while running an affected version

The system is affected if it runs any of the listed macOS, iOS, iPadOS, or watchOS versions and processes a malicious font file.

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 5.3.9 / 6.2.9 / 7.1 or later
Fixed in 5.3.96.2.97.1
Interim mitigation

Apply the relevant security updates (iOS 12.4.9/14.2, iPadOS 14.2, watchOS 5.3.9/6.2.9/7.1, macOS High Sierra/Mojave/Catalina/Big Sur 11.0.1 updates) to all affected devices to remediate the vulnerability.

Recommended fix High confidence

iOS 14.2/iPadOS 14.2, macOS Big Sur 11.0.1, macOS Catalina 10.15.7+Security Update 2020-006, or watchOS 7.1 (depending on device)

  1. Identify the device type (iPhone, iPad, Mac, or Apple Watch)
  2. Identify the current installed operating system version
  3. For iPhone/iPad: Upgrade to iOS 14.2 or iPadOS 14.2 (if compatible), or iOS 12.4.9 (for older devices)
  4. For Mac: Upgrade to macOS Big Sur 11.0.1, macOS Catalina 10.15.7 (with Security Update 2020-006), or apply Security Update 2020-006 to macOS High Sierra/Mojave
  5. For Apple Watch: Upgrade to watchOS 7.1, 6.2.9, or 5.3.9 depending on the current watchOS version
  6. Back up important data before performing the upgrade
  7. Connect device to power and Wi-Fi before initiating the update
  8. Install the update via Settings > General > Software Update (iOS/iPadOS) or System Preferences > Software Update (macOS)
Caveat Some older devices may not support the latest iOS/iPadOS versions; iOS 14.2 requires iPhone 6s or later, iPad Pro, iPad Air 2, iPad mini 4, or iPad 5th generation or later

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

Fix this in Ipados Exploited in the wild — priority engagement
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA2.0 h
20.0 hours of engineering $3,500
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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-2020-27930 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