SafariWeb browser · Apple
CVE-2020-9952
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 14.0 and iPadOS 14.0, tvOS 14.0, watchOS 7.0, Safari 14.0, iCloud for Windows 11.4, iCloud for Windows 7.21. 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 confidenceInput validation vulnerability in WebKit allowing cross-site scripting (XSS) when processing maliciously crafted web content. Fixed in iOS 14.0, iPadOS 14.0, tvOS 14.0, watchOS 7.0, Safari 14.0, and iCloud for Windows versions 11.4 and 7.21.
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
< 14.0< 7.21>= 11.0, < 11.4< 14.0< 14.0< 14.0< 7.0<= 2.30.3CVSS 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
- Low
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L
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.
-
Check Safari version on macOSOpen Safari, go to Safari menu > About Safari. The version number is displayed in the window.Affected if Version is earlier than 14.0 (e.g., 13.1.x, 13.0.x, etc.)
-
Check iOS version on iPhone or iPadGo to Settings > General > About. The version number is shown next to 'Software Version'.Affected if Version is earlier than 14.0 (e.g., 13.7, 13.6, etc.)
-
Check tvOS version on Apple TVGo to Settings > General > About TV. The version is displayed next to 'tvOS'.Affected if Version is earlier than 14.0 (e.g., 13.4, 13.3, etc.)
-
Check watchOS version on Apple WatchOpen the Watch app on iPhone, go to My Watch > General > About. The version is shown next to 'Version'.Affected if Version is earlier than 7.0 (e.g., 6.2, 6.1, etc.)
-
Check iCloud for Windows versionOpen iCloud on Windows, click the gear icon or go to Help > About. The version number is displayed in the about window.Affected if Version is 7.21 or higher but lower than 11.4, OR version 11.0 to 11.3 inclusive
-
Check WebKitGTK+ version on LinuxFor webkit2gtk-4.0, run: dpkg -l | grep webkit or pkg-config --modversion webkit2gtk-4.0. For webkit2gtk-4.1, use webkit2gtk-4.1.Affected if Version is 2.30.3 or earlier
A user is affected if any WebKit-based product they use (Safari, iOS, iPadOS, tvOS, watchOS, iCloud for Windows, or WebKitGTK+) is at a version lower than the fixed release numbers.
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 data7.07.2111.4
Apply vendor patches by updating all affected Apple devices (iOS, iPadOS, tvOS, watchOS, Safari, iCloud for Windows) to the fixed versions 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-2020-9952 — 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-2020-9952 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
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.
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