SafariWeb browser · Apple
CVE-2020-3902
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 · uneditedAn input validation issue was addressed with improved input validation. This issue is fixed in iOS 13.4 and iPadOS 13.4, tvOS 13.4, 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 a cross site scripting attack.
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 confidenceThis is a cross-site scripting (XSS) vulnerability caused by improper input validation in Apple's WebKit browser engine. Processing maliciously crafted web content allows attackers to execute arbitrary JavaScript in the context of the victim's session.
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< 13.4CVSS 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
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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 checksWork through these to decide whether this CVE applies to you.
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Check Safari versionOpen Safari, then go to Safari menu > About Safari. Compare the version number shown to 13.1.Affected if Version displayed is less than 13.1
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Check iOS version on iPhoneGo to Settings > General > About on the device. Look for the 'Version' field.Affected if Version shown is less than 13.4 (e.g., 13.3.x or earlier)
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Check iPadOS version on iPadGo to Settings > General > About on the device. Look for the 'Version' field.Affected if Version shown is less than 13.4 (e.g., 13.3.x or earlier)
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Check tvOS version on Apple TVGo to Settings > General > About TV on the Apple TV device.Affected if Version shown is less than 13.4 (e.g., 13.3.x or earlier)
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Check iTunes version on WindowsOpen iTunes, then go to Help > About iTunes. The version number appears in the dialog.Affected if Version shown is less than 12.10.5
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Check iCloud for Windows versionOpen iCloud, then go to the iCloud menu > About iCloud. The version is displayed.Affected if Version shown is less than 10.9.3
You are affected if any of these Apple products are installed with a version below its threshold and the WebKit-based browser or web rendering component is actively used.
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 data10.9.312.10.513.1
Apply vendor-supplied updates: upgrade to iOS 13.4/iPadOS 13.4, tvOS 13.4, Safari 13.1, iTunes 12.10.5, iCloud Windows 10.9.3/7.18 or later.
Fix this in Safari
Scoped from the published advisory
- Consultation2.0 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 $4,480.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-3902 — 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-2020-3902 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