dbcve.org
IcloudApplication · Apple

CVE-2021-1857

MEDIUM · 6.5 CVSS v3.1 Published 2021-09-08
Fix available
A fix is available. Upgrade to 7.4 / 11.3 or later.
See remediation →
72/100
Remediation priority · Elevated
Remotely reachable 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 memory initialization issue was addressed with improved memory handling. This issue is fixed in iTunes 12.11.3 for Windows, Security Update 2021-002 Catalina, Security Update 2021-003 Mojave, iCloud for Windows 12.3, macOS Big Sur 11.3, watchOS 7.4, tvOS 14.5, iOS 14.5 and iPadOS 14.5. Processing maliciously crafted web content may disclose sensitive 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 memory initialization flaw in WebKit allows processing of maliciously crafted web content to disclose sensitive user information. This is an information disclosure vulnerability stemming from improper memory handling that can leak data from uninitialized memory regions during web content processing.

MitigationApply the appropriate security updates for the affected Apple products: iOS 14.5/iPadOS 14.5, macOS Big Sur 11.3, watchOS 7.4, tvOS 14.5, iTunes 12.11.3 for Windows, iCloud for Windows 12.3, and Security Updates 2021-002/2021-003 for Catalina and Mojave.

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
IcloudApplication
Affected:< 12.3
ItunesApplication
Affected:< 12.11.3
IpadosOperating system
Affected:< 14.5
Iphone OsOperating system
Affected:< 14.5
Mac Os XOperating system
Affected:= 10.14= 10.14.0= 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
macOSOperating system
Affected:>= 11.0, < 11.3
TvosOperating system
Affected:< 14.5
WatchosOperating system
Affected:< 7.4

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
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 checks

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

  1. Check iOS or iPadOS version
    Go to Settings > General > About > Version on the device
    Affected if Version is less than 14.5 (for iOS or iPadOS)
  2. Check macOS version
    Go to System Preferences > About > Version, or run 'sw_vers' in Terminal
    Affected if Version starts with 10.14.x, 10.15.x, or is 11.0 through 11.2.x (inclusive)
  3. Check watchOS version
    Open the Watch app on paired iPhone, go to My Watch > About > Version
    Affected if Version is less than 7.4
  4. Check tvOS version
    Go to Settings > About > Version on Apple TV
    Affected if Version is less than 14.5
  5. Check iTunes for Windows version
    Open iTunes > Help > About iTunes, or check Programs and Features
    Affected if Version is less than 12.11.3
  6. Check iCloud for Windows version
    Open iCloud app > About iCloud, or check Programs and Features
    Affected if Version is less than 12.3

Your environment is affected if any of the Apple products listed are installed with a version below the thresholds specified in the affected version ranges.

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 7.4 / 11.3 / 12.3 or later
Fixed in 7.411.312.3
Interim mitigation

Apply the appropriate security updates for the affected Apple products: iOS 14.5/iPadOS 14.5, macOS Big Sur 11.3, watchOS 7.4, tvOS 14.5, iTunes 12.11.3 for Windows, iCloud for Windows 12.3, and Security Updates 2021-002/2021-003 for Catalina and Mojave.

Recommended fix High confidence

Upgrade to iOS 14.5, iPadOS 14.5, macOS Big Sur 11.3, Security Update 2021-002/2021-003, iCloud for Windows 12.3, iTunes 12.11.3, tvOS 14.5, or watchOS 7.4 depending on platform

  1. For iOS devices (iPhone and iPad): Go to Settings > General > Software Update and install iOS/iPadOS 14.5
  2. For macOS Big Sur (11.x): Go to System Preferences > Software Update and install macOS Big Sur 11.3
  3. For macOS Catalina (10.15): Install Security Update 2021-002 from System Preferences > Software Update
  4. For macOS Mojave (10.14): Install Security Update 2021-003 from System Preferences > Software Update
  5. For iCloud for Windows: Update to version 12.3 via Microsoft Store or Apple website
  6. For iTunes Windows: Update to version 12.11.3
  7. For tvOS devices: Go to Settings > System > Software Update and install tvOS 14.5
  8. For watchOS devices: Update via i Watch app on iPhone to watchOS 7.4
Caveat Standard OS/software updates may include feature changes; backup data before updating

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

Fix this in Icloud 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
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,560.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-1857 — 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-2021-1857 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