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IcloudApplication · Apple

CVE-2020-3910

CRITICAL · 9.8 CVSS v3.1 Published 2020-04-01
Fix available
A fix is available. Upgrade to 6.2 / 10.9.3 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges 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 buffer overflow was addressed with improved size validation. This issue is fixed in iOS 13.4 and iPadOS 13.4, macOS Catalina 10.15.4, tvOS 13.4, watchOS 6.2, iTunes for Windows 12.10.5, iCloud for Windows 10.9.3, iCloud for Windows 7.18. Multiple issues in libxml2.

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

Buffer overflow vulnerability in libxml2 library, addressed with improved size validation. Multiple distinct issues in the XML parsing library were fixed across Apple's product line.

MitigationApply available security updates to all affected products: iOS 13.4+/iPadOS 13.4+, macOS 10.15.4+, tvOS 13.4+, watchOS 6.2+, iTunes 12.10.5+ for Windows, and iCloud for Windows 10.9.3+/7.18+.

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:< 10.9.3
ItunesApplication
Affected:< 12.10.5
IpadosOperating system
Affected:< 13.4
Iphone OsOperating system
Affected:< 13.4
Mac Os XOperating system
Affected:< 10.15.4
TvosOperating system
Affected:< 13.4
WatchosOperating system
Affected:< 6.2

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
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/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. Identify the installed Apple product
    Determine which Apple application or operating system is in use (iCloud for Windows, iTunes for Windows, iPadOS, iOS, macOS, tvOS, or watchOS)
    Affected if Any of the affected Apple products listed below are installed
  2. Check iCloud for Windows version
    Open iCloud, click the gear icon or menu, and select 'About iCloud' to view the version number
    Affected if Version is earlier than 10.9.3
  3. Check iTunes for Windows version
    Open iTunes, go to Help > About iTunes to display the version
    Affected if Version is earlier than 12.10.5
  4. Check macOS version
    Click the Apple menu, select 'About This Mac' to view the macOS version number
    Affected if Version is earlier than 10.15.4 (Catalina)
  5. Check iOS/iPadOS/tvOS/watchOS version
    On the device, go to Settings > General > About to view the iOS/iPadOS version; on Apple TV go to Settings > General > About; on Apple Watch go to the Watch app on iPhone > General > About
    Affected if iOS or iPadOS is earlier than 13.4, tvOS is earlier than 13.4, or watchOS is earlier than 6.2

A user is affected if any installed Apple product (iCloud, iTunes, iOS, iPadOS, macOS, tvOS, or watchOS) has a version number lower than the fixed versions specified in the affected ranges.

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 6.2 / 10.9.3 / 10.15.4 or later
Fixed in 6.210.9.310.15.4
Interim mitigation

Apply available security updates to all affected products: iOS 13.4+/iPadOS 13.4+, macOS 10.15.4+, tvOS 13.4+, watchOS 6.2+, iTunes 12.10.5+ for Windows, and iCloud for Windows 10.9.3+/7.18+.

Recommended fix High confidence

iOS 13.4/iPadOS 13.4, macOS Catalina 10.15.4, tvOS 13.4, watchOS 6.2, iTunes 12.10.5, iCloud for Windows 10.9.3

  1. For iPhone/iPad: Upgrade to iOS 13.4 or iPadOS 13.4 or later via Settings > General > Software Update
  2. For Mac: Upgrade to macOS Catalina 10.15.4 or later via System Preferences > Software Update
  3. For Apple TV: Upgrade to tvOS 13.4 or later via Settings > System > Software Updates
  4. For Apple Watch: Upgrade to watchOS 6.2 or later via the Watch app on iPhone
  5. For Windows iTunes: Upgrade to iTunes 12.10.5 or later
  6. For Windows iCloud: Upgrade to iCloud for Windows 10.9.3 or later

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

Fix this in Icloud Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,800
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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-2020-3910 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