dbcve.org
SafariWeb browser · Apple

CVE-2021-30795

HIGH · 8.8 CVSS v3.1 Published 2021-09-08
Fix available
A fix is available. Upgrade to 7.6 / 11.5 or later.
See remediation →
95/100
Remediation priority · Urgent
Remotely reachable No privileges

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 · unedited
A use after free issue was addressed with improved memory management. 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 confidence

A use-after-free vulnerability in WebKit allows arbitrary code execution when processing maliciously crafted web content. The vulnerability exists in Safari and UIWebView components across multiple Apple platforms.

MitigationApply the vendor-supplied security updates: iOS 14.7+, Safari 14.1.2+, macOS Big Sur 11.5+, watchOS 7.6+, and tvOS 14.7+. Until patched, avoid untrusted websites.

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
Affected:< 14.1.2
Iphone OsOperating system
Affected:< 14.7
macOSOperating system
Affected:>= 11.0, < 11.5
TvosOperating system
Affected:< 14.7
WatchosOperating system
Affected:< 7.6

CVSS 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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify the Apple product running WebKit
    Determine which Apple device and software you are using: Safari browser on macOS, Safari on iOS/iPadOS, Safari on watchOS, or the WebKit framework in a tvOS app. Check the device model and operating system.
    Affected if The device runs any of the affected products: Safari, iOS, tvOS, or watchOS.
  2. Check Safari version on macOS
    Open Safari, click Safari menu > About Safari. Compare the version number to the affected range: versions before 14.1.2 on macOS are vulnerable.
    Affected if Safari version is earlier than 14.1.2 on macOS.
  3. Check iOS version on iPhone/iPad
    Go to Settings > General > About. Look at the Software Version. Compare to the affected range: versions before 14.7 are vulnerable.
    Affected if iOS version is earlier than 14.7.
  4. Check macOS version
    Click Apple menu > About This Mac. Look at the macOS version. The affected range is macOS Big Sur 11.0 through 11.4 (versions before 11.5).
    Affected if macOS Big Sur version is 11.0 through 11.4.
  5. Check tvOS or watchOS version
    On Apple TV: go to Settings > General > About > Version. On Apple Watch: open the Watch app on iPhone > General > About. Compare to affected ranges: tvOS before 14.7, watchOS before 7.6.
    Affected if tvOS is earlier than 14.7 or watchOS is earlier than 7.6.

A user is affected if their Safari browser is below 14.1.2, or their iOS is below 14.7, or their macOS Big Sur is 11.0-11.4, or their tvOS is below 14.7, or their watchOS is below 7.6.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Upgrade available Upgrade to 7.6 / 11.5 / 14.1.2 or later
Fixed in 7.611.514.1.2
Interim mitigation

Apply the vendor-supplied security updates: iOS 14.7+, Safari 14.1.2+, macOS Big Sur 11.5+, watchOS 7.6+, and tvOS 14.7+. Until patched, avoid untrusted websites.

Recommended fix High confidence

iOS 14.7, Safari 14.1.2, macOS Big Sur 11.5, watchOS 7.6, tvOS 14.7 (depending on device)

  1. For iOS devices: Go to Settings > General > Software Update and update to iOS 14.7
  2. For macOS: Go to System Preferences > Software Update and update to macOS Big Sur 11.5
  3. For Safari: Update to Safari 14.1.2 which is included with macOS Big Sur 11.5
  4. For watchOS: Use the Watch app on your iPhone to update watchOS to 7.6
  5. For tvOS: Go to Settings > System > Software Updates and update to tvOS 14.7
Caveat Standard OS update considerations apply - review Apple release notes for any compatibility issues with existing software

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Safari Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-30795 in production — separate from our analysis above.

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.

What this is

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.

What belongs here
  • 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