dbcve.org
SafariWeb browser · Apple

CVE-2019-8556

HIGH · 8.8 CVSS v3.1 Published 2019-12-18
Fix available
A fix is available. Upgrade to 7.11 / 12.1 or later.
See remediation →
95/100
Remediation priority · Urgent
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 use after free issue was addressed with improved memory management. This issue is fixed in iOS 12.2, tvOS 12.2, Safari 12.1, iTunes 12.9.4 for Windows, iCloud for Windows 7.11. Processing maliciously crafted web content 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

This is a use-after-free vulnerability in WebKit, the browser engine used by Safari and iOS/tvOS applications. When processing maliciously crafted web content, the browser fails to properly manage memory allocation and deallocation, allowing an attacker to access freed memory and potentially execute arbitrary code.

MitigationUpdate all affected Apple products (iOS 12.2+, tvOS 12.2+, Safari 12.1+, iTunes 12.9.4+, iCloud for Windows 7.11+) to the patched versions. Until patched, avoid visiting untrusted websites.

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
SafariWeb browser
Affected:< 12.1
IcloudApplication
Affected:< 7.11
ItunesApplication
Affected:< 12.9.4
Iphone OsOperating system
Affected:< 12.2
TvosOperating system
Affected:< 12.2

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

CVSS:3.1/AV:N/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 installed Apple products
    Check which of these are installed: Safari (macOS), iOS device (iPhone/iPad), tvOS device (Apple TV), iTunes (Windows/macOS), iCloud for Windows
    Affected if Any of the affected products (Safari, iOS, tvOS, iTunes, iCloud) are installed on the system
  2. Check Safari version on macOS
    Open Safari > Safari menu > About Safari. Compare the version number to 12.1 (any version below 12.1 is vulnerable)
    Affected if Safari version is below 12.1 and Safari is used to browse web content
  3. Check iOS version on iPhone or iPad
    Go to Settings > General > About. Look for the version number (e.g., 12.1.x). Compare to 12.2 (any version below 12.2 is vulnerable)
    Affected if iOS version is below 12.2 and the device is used to browse web content via Safari or any app using WebKit
  4. Check tvOS version on Apple TV
    Go to Settings > General > About > Version. Compare to 12.2 (any version below 12.2 is vulnerable)
    Affected if tvOS version is below 12.2 and the Apple TV is used to browse web content
  5. Check iTunes version on Windows or macOS
    Open iTunes > Help > About iTunes. Compare the version number to 12.9.4 (any version below 12.9.4 is vulnerable)
    Affected if iTunes version is below 12.9.4 and iTunes is used to access iTunes Store or web content
  6. Check iCloud for Windows version
    Open iCloud > Click the gear icon or look for version information. Compare to 7.11 (any version below 7.11 is vulnerable)
    Affected if iCloud for Windows version is below 7.11

The environment is affected if any installed Apple product (Safari < 12.1, iOS < 12.2, tvOS < 12.2, iTunes < 12.9.4, iCloud for Windows < 7.11) is used to process untrusted web content.

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.

From vendor data
Upgrade available Upgrade to 7.11 / 12.1 / 12.2 or later
Fixed in 7.1112.112.2
Interim mitigation

Update all affected Apple products (iOS 12.2+, tvOS 12.2+, Safari 12.1+, iTunes 12.9.4+, iCloud for Windows 7.11+) to the patched versions. Until patched, avoid visiting untrusted websites.

Fix this in Safari 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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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-2019-8556 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