CVE-2021-30897
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 issue existed in the specification for the resource timing API. The specification was updated and the updated specification was implemented. This issue is fixed in macOS Monterey 12.0.1. A malicious website may exfiltrate data cross-origin.
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 confidenceThe Resource Timing API in macOS Safari had a cross-origin information disclosure vulnerability where a malicious website could exfiltrate data by measuring timing information of cross-origin resources, violating the same-origin policy. The specification was updated and the fix shipped in macOS Monterey 12.0.1.
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< 15.0< 15.0< 12.0.1< 15.0CVSS 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
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/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 macOS versionGo to Apple menu > About This Mac and note the version number under macOS, or run 'sw_vers -productVersion' in TerminalAffected if The version is below 12.0.1
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Check iOS version (iPhone)Go to Settings > General > About and note the version number, or connect to computer and run 'idevicesyslog' or check in Finder/iTunesAffected if The version is below 15.0
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Check iPadOS version (iPad)Go to Settings > General > About and note the version numberAffected if The version is below 15.0
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Check tvOS version (Apple TV)Go to Settings > General > About > Version on the Apple TV, or use the TV app on a connected deviceAffected if The version is below 15.0
If any of the installed operating systems (macOS, iOS, iPadOS, or tvOS) are below their respective fixed versions (12.0.1, 15.0, 15.0, 15.0), the Safari Resource Timing API vulnerability is present and cross-origin timing information can be exfiltrated by malicious websites.
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 · scoped12.0.115.0
Update affected systems to macOS Monterey 12.0.1 or later to receive the vendor patch that implements the corrected Resource Timing API specification.
iOS 15.0+, iPadOS 15.0+, macOS 12.0.1+, tvOS 15.0+
- Ensure all device backups are completed before proceeding with the OS update
- For iPhone/iPad: Connect device to power and Wi-Fi, then go to Settings > General > Software Update to download and install iOS/iPadOS 15.0 or later
- For Mac: Open System Preferences > Software Update, or go to Apple menu > System Preferences > Software Update, to install macOS Monterey 12.0.1 or later
- For Apple TV: Go to Settings > System > Software Updates > Update Software to install tvOS 15.0 or later
- After updating, verify the version by checking Settings > General > About on iOS devices, or System Preferences > About on Mac
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation1.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-30897 — 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-2021-30897 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