dbcve.org
IpadosOperating system · Apple

CVE-2021-30881

HIGH · 7.8 CVSS v3.1 Published 2021-08-24
Fix available
A fix is available. Upgrade to 8.1 / 10.15.7 or later.
See remediation →
81/100
Remediation priority · High
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
An input validation issue was addressed with improved memory handling. This issue is fixed in iOS 15.1 and iPadOS 15.1, macOS Monterey 12.0.1, tvOS 15.1, watchOS 8.1, Security Update 2021-007 Catalina, macOS Big Sur 11.6.1. Unpacking a maliciously crafted archive 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 memory handling vulnerability in archive unpacking functionality allows arbitrary code execution when a user unpacks a maliciously crafted archive file. The issue was addressed through improved input validation and proper memory management during archive processing.

MitigationApply the applicable Apple security update (iOS 15.1, iPadOS 15.1, macOS Monterey 12.0.1/Big Sur 11.6.1/Catalina Security Update 2021-007, tvOS 15.1, or watchOS 8.1) to all affected devices and systems.

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
IpadosOperating system
Affected:< 15.1
Iphone OsOperating system
Affected:< 15.1
Mac Os XOperating system
Affected:< 10.15.7= 10.15.7
macOSOperating system
Affected:>= 11.0, < 11.6.1= 12.0
TvosOperating system
Affected:< 15.1
WatchosOperating system
Affected:< 8.1

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
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 checks

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

  1. Identify your Apple device type
    Determine whether the device is an iPhone, iPad, Mac, Apple TV, or Apple Watch. On iPhone/iPad: check the model name in Settings > General > About. On Mac: check Apple menu > About This Mac. On Apple TV: check Settings > General > About. On Apple Watch: check the model on the watch or via the Watch app on paired iPhone.
    Affected if Device is any Apple product (iPhone, iPad, Mac, Apple TV, Apple Watch)
  2. Check the installed iOS or iPadOS version
    On iPhone or iPad, go to Settings > General > About and note the Version number (for example, 15.0 or 14.7.1).
    Affected if iOS or iPadOS version is lower than 15.1
  3. Check the installed macOS version
    On Mac, click Apple menu > About This Mac and note the macOS version (for example, 12.0, 11.5, or 10.15.7). Compare against the affected ranges: Catalina (10.15.7 or earlier), Big Sur (11.0 to 11.6.0), or Monterey (12.0).
    Affected if macOS version is 10.15.7 or earlier, between 11.0 and 11.6.0 inclusive, or exactly 12.0
  4. Check the installed tvOS or watchOS version
    On Apple TV: go to Settings > General > About > Version. On Apple Watch: open the Watch app on paired iPhone, go to My Watch > General > About, and note the watchOS version.
    Affected if tvOS version is lower than 15.1 or watchOS version is lower than 8.1

You are affected if your Apple device runs iOS/iPadOS, macOS, tvOS, or watchOS versions lower than the fixed releases (iOS 15.1, iPadOS 15.1, macOS 11.6.1/12.0.1/10.15.7 update, tvOS 15.1, or watchOS 8.1).

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 8.1 / 10.15.7 / 11.6.1 or later
Fixed in 8.110.15.711.6.1
Interim mitigation

Apply the applicable Apple security update (iOS 15.1, iPadOS 15.1, macOS Monterey 12.0.1/Big Sur 11.6.1/Catalina Security Update 2021-007, tvOS 15.1, or watchOS 8.1) to all affected devices and systems.

Recommended fix High confidence

iOS 15.1 / iPadOS 15.1 / macOS Monterey 12.0.1 / tvOS 15.1 / watchOS 8.1 / Security Update 2021-007 Catalina / macOS Big Sur 11.6.1

  1. For iPhone/iPad: Go to Settings > General > Software Update and install iOS/iPadOS 15.1 or later
  2. For macOS Big Sur (11.x): Go to System Preferences > Software Update and install macOS Big Sur 11.6.1
  3. For macOS Monterey (12.0): Go to System Preferences > Software Update and install macOS Monterey 12.0.1
  4. For macOS Catalina (10.15.7): Install Security Update 2021-007 Catalina via System Preferences > Software Update
  5. For tvOS: Go to Settings > System > Software Updates and install tvOS 15.1 or later
  6. For watchOS: On iPhone, open Watch app, go to My Watch > General > Software Update and install watchOS 8.1 or later
  7. Alternatively, manually download the latest IPSW firmware from https://developer.apple.com/download/ and restore via Finder or Xcode
Caveat Apple security updates typically have minimal breaking changes; however, users should back up their device before updating

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

Fix this in Ipados Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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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-2021-30881 in production — separate from our analysis above.

No notes yet

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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