dbcve.org
IcloudApplication · Apple

CVE-2020-3911

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 bounds checking. 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

A buffer overflow vulnerability in libxml2 was addressed with improved bounds checking. The flaw could allow remote code execution or denial of service via maliciously crafted XML content. The issue affects multiple Apple products including iOS, macOS, tvOS, watchOS, and Windows software using the library.

MitigationApply vendor-supplied patches by updating all affected Apple devices and software to the fixed versions: iOS 13.4/iPadOS 13.4, macOS Catalina 10.15.4, tvOS 13.4, watchOS 6.2, iTunes 12.10.5, 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 installed Apple products
    Check for iOS, iPadOS, macOS, tvOS, watchOS, iTunes, or iCloud for Windows on the system
    Affected if Any of these products are present
  2. Check iOS or iPadOS version
    Go to Settings > General > About > Version on the device
    Affected if Version is lower than 13.4
  3. Check macOS version
    Click Apple menu > About This Mac; the version number appears below the name
    Affected if Version is lower than 10.15.4 (Catalina)
  4. Check tvOS or watchOS version
    On Apple TV: Settings > General > About > Version; On Apple Watch: Watch app on iPhone > My Watch > General > About
    Affected if tvOS version is lower than 13.4 or watchOS version is lower than 6.2
  5. Check iTunes version
    Open iTunes > Help > About iTunes; the version is shown in the About window
    Affected if Version is lower than 12.10.5
  6. Check iCloud for Windows version
    Open iCloud for Windows > click the menu icon > About iCloud; the version is displayed
    Affected if Version is lower than 10.9.3 or 7.18 (depending on release channel)

If any Apple product listed above is installed and its version falls below the fixed version (iOS/iPadOS 13.4, macOS 10.15.4, tvOS 13.4, watchOS 6.2, iTunes 12.10.5, iCloud 10.9.3/7.18), the environment is vulnerable to CVE-2020-3911.

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 vendor-supplied patches by updating all affected Apple devices and software to the fixed versions: iOS 13.4/iPadOS 13.4, macOS Catalina 10.15.4, tvOS 13.4, watchOS 6.2, iTunes 12.10.5, 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 (or 7.18)

  1. For iPhone/iPad: Go to Settings > General > Software Update and upgrade to iOS 13.4/iPadOS 13.4 or later
  2. For Mac: Go to System Preferences > Software Update and upgrade to macOS Catalina 10.15.4 or later
  3. For Apple Watch: On your iPhone, open the Watch app, go to General > Software Update, and upgrade to watchOS 6.2 or later
  4. For Apple TV: Go to Settings > System > Software Updates and upgrade to tvOS 13.4 or later
  5. For iTunes (Windows): Download and install iTunes 12.10.5 or later from apple.com/itunes
  6. For iCloud (Windows): Download and install iCloud for Windows 10.9.3 or later (or iCloud for Windows 7.18 for the 7.x line)
Caveat Standard OS update considerations apply - review Apple's release notes for any app compatibility or feature changes before upgrading

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

Fix this in Icloud Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2020-3911 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2020-3911 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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