CVE-2021-30657
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 logic issue was addressed with improved state management. This issue is fixed in macOS Big Sur 11.3, Security Update 2021-002 Catalina. A malicious application may bypass Gatekeeper checks. Apple is aware of a report that this issue may have been actively exploited..
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 confidenceThis is a logic vulnerability in macOS Gatekeeper that allows a malicious application to bypass security checks. The flaw involved improper state management that could be exploited by specially crafted applications to evade macOS's application verification system.
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>= 10.15, <= 10.15.5= 10.15.6= 10.15.7>= 11.0, < 11.3CVSS 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
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/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 installed macOS versionOpen Terminal and run: sw_vers -productVersionAffected if The version is 10.15.x (10.15 through 10.15.7) or 11.0 through 11.2.x, meaning the system is running a vulnerable macOS release before the fixes in Security Update 2021-002 (Catalina) or macOS 11.3 (Big Sur)
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Verify Gatekeeper is enabledRun: spctl --status in Terminal. Look for "master" or "enabled" in the outputAffected if Gatekeeper is enabled but the version is in the affected range - the vulnerability bypasses Gatekeeper's signature and quarantine enforcement, so a bypass could be present regardless of Gatekeeper status
If the macOS version is 10.15.x through 10.15.7 or 11.0 through 11.2.x, the environment is vulnerable to CVE-2021-30657 and may have been exploited if untrusted applications were run
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 · scoped11.3
Apply the available macOS security updates: Big Sur 11.3 or Security Update 2021-002 for Catalina. Ensure all systems are patched promptly given confirmed active exploitation in the wild.
macOS Big Sur 11.3 or later; or Security Update 2021-002 for Catalina
- Check current macOS version by clicking Apple menu > About This Mac
- If running macOS 11.0 to 11.2.x (Big Sur), upgrade to macOS 11.3 or later via System Preferences > Software Update
- If running macOS 10.15.x (Catalina), install Security Update 2021-002 via System Preferences > Software Update
- Verify the update was successfully applied by checking About This Mac again
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
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,424.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-30657 — 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-2021-30657 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