dbcve.org
SafariWeb browser · Apple

CVE-2020-9843

HIGH · 7.1 CVSS v3.1 Published 2020-06-09
Fix available
A fix is available. Upgrade to 6.2.5 / 7.19 or later.
See remediation →
78/100
Remediation priority · High
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
An input validation issue was addressed with improved input validation. This issue is fixed in iOS 13.5 and iPadOS 13.5, tvOS 13.4.5, watchOS 6.2.5, Safari 13.1.1, iTunes 12.10.7 for Windows, iCloud for Windows 11.2, iCloud for Windows 7.19. Processing maliciously crafted web content may lead to a cross site scripting attack.

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 · moderate confidence

CVE-2020-9843 is a cross-site scripting (XSS) vulnerability in Apple's WebKit engine caused by insufficient input validation. Processing maliciously crafted web content allows attackers to execute arbitrary JavaScript in the context of the victim's browser, potentially stealing cookies, session tokens, or performing actions on behalf of the user.

MitigationApply the vendor-supplied patches by updating to iOS 13.5/iPadOS 13.5, tvOS 13.4.5, watchOS 6.2.5, Safari 13.1.1, iTunes 12.10.7, or iCloud for Windows 11.2/7.19 as appropriate for each affected 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
SafariWeb browser
Affected:< 13.1.1
IcloudApplication
Affected:< 7.19>= 11.0, < 11.2
ItunesApplication
Affected:< 12.10.7
IpadosOperating system
Affected:< 13.5
Iphone OsOperating system
Affected:< 13.5
TvosOperating system
Affected:< 13.4.5
WatchosOperating system
Affected:< 6.2.5

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
Changed
Confidentiality
Low
Integrity
Low
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L

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 WebKit-based browsers or apps in use
    Check for installed Apple browsers that use the WebKit engine, primarily Safari on macOS/iOS/iPadOS, or third-party browsers that rely on WebKit
    Affected if Any WebKit-based browser or app is installed and used to process untrusted web content
  2. Check Safari version on macOS
    Open Safari, go to Safari > About Safari to view the version number, or run 'defaults read /Applications/Safari.app/Contents/Info CFBundleShortVersionString' in Terminal
    Affected if Version is earlier than 13.1.1
  3. Check iOS or iPadOS version
    Go to Settings > General > About on the device and look at the Version field
    Affected if iOS or iPadOS version is earlier than 13.5
  4. Check tvOS or watchOS version
    On Apple TV go to Settings > General > About > Version; on Apple Watch go to the Watch app on iPhone > General > About
    Affected if tvOS is earlier than 13.4.5 or watchOS is earlier than 6.2.5
  5. Check iTunes version on Windows or macOS
    Open iTunes, go to Help > About iTunes, or check the program version in Programs and Features
    Affected if iTunes version is earlier than 12.10.7
  6. Check iCloud for Windows version
    Open iCloud, click on the gear icon or look in the app version information
    Affected if iCloud for Windows version is 7.x and earlier than 7.19, or 11.x and earlier than 11.2

The environment is affected if any Apple product using WebKit (Safari, iOS, iPadOS, tvOS, watchOS, iTunes, iCloud for Windows) has a version lower than the fixed versions (Safari 13.1.1, iOS/iPadOS 13.5, tvOS 13.4.5, watchOS 6.2.5, iTunes 12.10.7, iCloud 7.19 or 11.2) and processes 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 6.2.5 / 7.19 / 11.2 or later
Fixed in 6.2.57.1911.2
Interim mitigation

Apply the vendor-supplied patches by updating to iOS 13.5/iPadOS 13.5, tvOS 13.4.5, watchOS 6.2.5, Safari 13.1.1, iTunes 12.10.7, or iCloud for Windows 11.2/7.19 as appropriate for each affected system.

Fix this in Safari Scoped from the published advisory
  • Consultation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
5.0 hours of engineering $880
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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-2020-9843 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