SafariWeb browser · Apple
CVE-2020-3901
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 · uneditedA type confusion issue was addressed with improved memory handling. This issue is fixed in iOS 13.4 and iPadOS 13.4, tvOS 13.4, watchOS 6.2, Safari 13.1, iTunes for Windows 12.10.5, iCloud for Windows 10.9.3, iCloud for Windows 7.18. Processing maliciously crafted web content 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 confidenceA type confusion vulnerability in WebKit (Apple's browser engine) allows remote code execution when processing maliciously crafted web content. The vulnerability stemmed from improper memory handling that could be exploited to corrupt memory and execute arbitrary code. This affected Safari and Apple services across iOS, iPadOS, tvOS, watchOS, and Windows-based iTunes/iCloud clients.
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
SafariWeb browser
< 13.1< 10.9.3< 12.10.5< 13.4< 13.4< 13.4< 6.2CVSS 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
- High
- Availability
- High
CVSS:3.1/AV:N/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 Safari version on macOS or WindowsOpen Safari, go to Safari > About Safari (on Mac) or Help > About Safari (on Windows). The version number displays in the pop-up window.Affected if The version shown is earlier than 13.1 (for example, 13.0.x or 12.x)
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Check iTunes version on WindowsOpen iTunes, go to Help > About iTunes. The version number displays in the pop-up window.Affected if The version shown is earlier than 12.10.5
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Check iCloud for Windows versionOpen iCloud, click the gear icon or menu, then select About iCloud. The version number displays in the window.Affected if The version shown is earlier than 10.9.3
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Check iOS or iPadOS version on iPhone or iPadGo to Settings > General > About on the device. The version number is shown next to 'Version'.Affected if The version shown is earlier than 13.4 (for example, 13.3.x or earlier)
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Check tvOS version on Apple TVGo to Settings > General > About > Version on the Apple TV device.Affected if The version shown is earlier than 13.4
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Check watchOS version on Apple WatchOpen the Watch app on paired iPhone, go to My Watch > General > About. The watchOS version is displayed.Affected if The version shown is earlier than 6.2
A user is affected if any of their Apple software (Safari, iTunes, iCloud for Windows, iOS, iPadOS, tvOS, or watchOS) matches a version listed before the fixed release for that 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 data6.210.9.312.10.5
Apply vendor-supplied updates: iOS 13.4+, iPadOS 13.4+, tvOS 13.4+, watchOS 6.2+, Safari 13.1+, iTunes 12.10.5+, and iCloud for Windows 10.9.3/7.18+. Prioritize updating mobile devices and any systems running Safari or iTunes/iCloud for Windows.
Fix this in Safari
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
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 locallyCheck whether your project pulls in CVE-2020-3901 — 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-2020-3901 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