SafariWeb browser · Apple
CVE-2020-9947
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 use after free issue was addressed with improved memory management. This issue is fixed in watchOS 7.0, iOS 14.0 and iPadOS 14.0, iTunes for Windows 12.10.9, iCloud for Windows 11.5, tvOS 14.0, Safari 14.0. 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 use-after-free vulnerability in Safari/WebKit allows arbitrary code execution when processing maliciously crafted web content. The vulnerability stems from improper memory management that can be exploited to execute arbitrary code in the context of the current process.
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< 11.5.0>= 12.0.0, < 12.10.9< 14.0< 14.0< 14.0< 7.0CVSS 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 macOSOpen Safari, click Safari menu, select About Safari. The version number appears in the window.Affected if Version displayed is earlier than 14.0 (e.g., 13.x)
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Check iOS version on iPhone or iPadOpen Settings app, tap General, tap About. The version number is shown next to 'Version'.Affected if Version number is earlier than 14.0 (e.g., 13.x)
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Check iPadOS version on iPadOpen Settings app, tap General, tap About. The version number appears next to 'Version'.Affected if Version number is earlier than 14.0 (e.g., 13.x)
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Check watchOS version on Apple WatchOpen Watch app on paired iPhone, go to General, tap About. The watchOS version is listed.Affected if Version shown is earlier than 7.0 (e.g., 6.x)
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Check tvOS version on Apple TVGo to Settings, select General, then About. The tvOS version is displayed.Affected if Version shown is earlier than 14.0 (e.g., 13.x)
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Check iTunes version on WindowsOpen iTunes, click Help menu, select About iTunes. The version appears in the window.Affected if Version is 12.0.0 or later but earlier than 12.10.9
A user is affected if any of their Apple software (Safari, iOS, iPadOS, watchOS, tvOS, iTunes) runs a version lower than the patched releases: Safari/iOS/iPadOS/tvOS below 14.0, watchOS below 7.0, or iTunes below 12.10.9.
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 data7.011.5.012.10.9
Update affected Apple devices to iOS 14.0/iPadOS 14.0, watchOS 7.0, tvOS 14.0, Safari 14.0, or later versions. For Windows systems, update iTunes to 12.10.9+ and iCloud for Windows to 11.5+.
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-2020-9947 — 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-2020-9947 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