SafariWeb browser · Apple
CVE-2021-30758
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 state handling. This issue is fixed in iOS 14.7, Safari 14.1.2, macOS Big Sur 11.5, watchOS 7.6, tvOS 14.7. 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 (Safari's browser engine) allows processing of maliciously crafted web content to lead to arbitrary code execution. The issue was addressed with improved state handling and affects Safari 14.1.2, iOS 14.7, macOS Big Sur 11.5, watchOS 7.6, and tvOS 14.7.
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
< 14.1.2< 14.7< 11.5< 14.7< 7.6CVSS 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 > About Safari. Note the version number displayed.Affected if Version is earlier than 14.1.2 and you use Safari to browse the web
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Check iOS version on iPhone or iPadGo to Settings > General > About. Note the iOS version number.Affected if iOS version is earlier than 14.7 and you use Safari or any app that uses WebKit
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Check macOS Big Sur versionClick Apple menu > About This Mac. Note the macOS version number.Affected if macOS version is earlier than 11.5 and you use Safari or any WebKit-based application
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Check watchOS version on Apple WatchOpen Watch app on iPhone, select your watch, go to General > About. Note the watchOS version.Affected if watchOS version is earlier than 7.6 and you use Safari on Apple Watch
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Check tvOS version on Apple TVGo to Settings > General > About > Version. Note the tvOS version number.Affected if tvOS version is earlier than 14.7 and you use the WebKit-based browser on Apple TV
You are affected if any of your Apple devices run Safari or use WebKit-based features on versions below 14.1.2 (Safari), 14.7 (iOS/tvOS), 11.5 (macOS), or 7.6 (watchOS).
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.
dbcve · scoped7.611.514.1.2
Deploy vendor patches by updating to iOS 14.7+, Safari 14.1.2+, macOS Big Sur 11.5+, watchOS 7.6+, or tvOS 14.7+ on all affected devices.
Safari 14.1.2, iOS 14.7, macOS Big Sur 11.5, watchOS 7.6, tvOS 14.7 (or later respective major versions)
- Upgrade Safari to version 14.1.2 or later
- Upgrade iOS/iPhone OS to version 14.7 or later
- Upgrade macOS to Big Sur 11.5 or later
- Upgrade watchOS to version 7.6 or later
- Upgrade tvOS to version 14.7 or later
- After upgrading, ensure WebKit is updated by visiting the Software Update section in Settings/Preferences
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Safari
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,560.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-30758 — 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-2021-30758 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