dbcve.org
Mac Os XOperating system · Apple

CVE-2021-30961

MEDIUM · 5.5 CVSS v3.1 Published 2021-08-24
Fix available
A fix is available. Upgrade to 11.6.2 or later.
See remediation →
58/100
Remediation priority · Elevated
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 buffer overflow issue was addressed with improved memory handling. This issue is fixed in Security Update 2021-008 Catalina, macOS Big Sur 11.6.2. Parsing a maliciously crafted audio file may lead to disclosure 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 confidence

A buffer overflow vulnerability exists in Apple's audio file parsing functionality. When parsing a maliciously crafted audio file, the application fails to properly handle memory allocation, causing a buffer overflow that can be exploited to disclose user information.

MitigationApply Security Update 2021-008 for macOS Catalina or update to macOS Big Sur 11.6.2 or later to patch the vulnerability.

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
Mac Os XOperating system
Affected:>= 10.15, <= 10.15.7= 10.15.7
macOSOperating system
Affected:>= 11.0, < 11.6.2

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
Local
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:L/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 checks

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

  1. Identify installed macOS version
    Run 'sw_vers' in Terminal or go to Apple menu > About This Mac to view the macOS version
    Affected if The version is 10.15.7 (Catalina) or falls between 11.0 and 11.6.1 (Big Sur)
  2. Confirm macOS build number
    Run 'system_profiler SPSoftwareDataType' in Terminal to see detailed version and build information
    Affected if Build number corresponds to an unpatched version of the affected releases
  3. Check if audio file parsing is in use
    The vulnerability is in CoreAudio framework; any application that processes audio files could trigger it. No specific feature toggle exists - the flaw is in the parsing code itself
    Affected if User processes audio files using native macOS audio handling on an affected version
  4. Verify security update status
    Check System Preferences > Software Update for available updates, or run 'softwareupdate --list' in Terminal
    Affected if Security Update 2021-008 (for Catalina) or the 11.6.2 security update (for Big Sur) has not been installed

A user is affected if their macOS version falls within 10.15 to 10.15.7 or 11.0 to 11.6.1 and the corresponding security patches have not been applied.

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 11.6.2 or later
Fixed in 11.6.2
Interim mitigation

Apply Security Update 2021-008 for macOS Catalina or update to macOS Big Sur 11.6.2 or later to patch the vulnerability.

Recommended fix High confidence

macOS 10.15.7 users: Security Update 2021-008 Catalina | macOS 11.0-11.6.1 users: macOS Big Sur 11.6.2

  1. Back up your Mac using Time Machine or another backup solution before applying updates
  2. Open System Preferences (on macOS 11+) or System Preferences (on macOS 10.15)
  3. Click on 'Software Update' to check for available updates
  4. For macOS 10.15.7 (Catalina): Install Security Update 2021-008 Catalina
  5. For macOS 11.0-11.6.1 (Big Sur): Install macOS Big Sur 11.6.2
  6. Restart your Mac when prompted to complete the installation
  7. Verify the update was successful by checking System Preferences > Software Update again

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

Fix this in Mac Os X Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,640
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,224.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-30961 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2021-30961 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