CVE-2021-30683
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 macOS Big Sur 11.4, Security Update 2021-003 Catalina, Security Update 2021-004 Mojave. A malicious application could execute arbitrary code leading to compromise of user information.
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 macOS that allows a malicious application to execute arbitrary code with user-level privileges, potentially compromising user information. The vulnerability exists due to improper memory management.
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>= 10.14, <= 10.14.5>= 10.15, <= 10.15.6= 10.14.6= 10.15.7>= 11.0, < 11.4CVSS 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
- Local
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/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 the installed macOS versionOpen Terminal and run: sw_vers -productVersionAffected if The version output starts with 10.14, 10.15, or 11.0-11.3 (not 11.4 or later)
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Confirm exact version falls within affected rangeCompare your version number to the affected list: 10.14.x, 10.15.x through 10.15.7, or 11.0.x through 11.3.xAffected if Your exact version matches any of these: 10.14, 10.14.1, 10.14.2, 10.14.3, 10.14.4, 10.14.5, 10.14.6, 10.15, 10.15.1, 10.15.2, 10.15.3, 10.15.4, 10.15.5, 10.15.6, 10.15.7, 11.0, 11.1, 11.2, 11.3
If the system runs macOS version 10.14.x, 10.15.x, or 11.0-11.3.x, it is within the affected range and the vulnerability may be present.
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 · scoped11.4
Apply the relevant macOS security update: macOS Big Sur 11.4, Security Update 2021-003 for Catalina, or Security Update 2021-004 for Mojave. Organizations should ensure patch management processes include these security updates.
macOS Big Sur 11.4, Security Update 2021-003 Catalina, or Security Update 2021-004 Mojave depending on current version
- Check the current macOS version by clicking the Apple menu and selecting About This Mac
- For macOS Big Sur (11.0-11.3): Update to macOS Big Sur 11.4 by going to System Preferences > Software Update
- For macOS Catalina (10.15.7 and earlier): Apply Security Update 2021-003 Catalina via System Preferences > Software Update
- For macOS Mojave (10.14.6 and earlier): Apply Security Update 2021-004 Mojave via System Preferences > Software Update
- Restart the computer after applying the security update
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation1.0 h
- Implementation2.0 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 $1,664.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-30683 — 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-2021-30683 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