SafariWeb browser · Apple
CVE-2020-9936
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 · uneditedAn out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 13.6 and iPadOS 13.6, macOS Catalina 10.15.6, tvOS 13.4.8, watchOS 6.2.8, iTunes 12.10.8 for Windows, iCloud for Windows 11.3, iCloud for Windows 7.20. Processing a maliciously crafted image 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 confidenceA memory corruption vulnerability in Apple's image processing components allows an out-of-bounds write when processing a specially crafted malicious image file. This memory safety issue was addressed with improved bounds checking in the affected components. Successful exploitation enables arbitrary code execution in the context of the application processing the image.
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
< 13.1.2< 7.20>= 11.0, < 11.3< 12.10.8< 13.6< 13.6< 13.4.8< 6.2.8CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Check Safari version on macOSOpen Safari, go to Safari > About Safari to display the version number. Compare it to the affected range: versions before 13.1.2.Affected if The displayed version is earlier than 13.1.2
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Check iCloud for Windows versionOpen iCloud, click the gear icon or menu to access About or Version Information. Compare to affected ranges: versions before 7.20, or between 11.0 and 11.3 (excluding 11.3).Affected if The version is less than 7.20, or greater than or equal to 11.0 but less than 11.3
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Check iTunes version on WindowsOpen iTunes, go to Help > About iTunes to display the version number. Compare to affected range: versions before 12.10.8.Affected if The displayed version is earlier than 12.10.8
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Check iOS version on iPhone or iPadGo to Settings > General > About on the iOS device. Note the version number. Compare to affected range: versions before 13.6.Affected if The iOS version shown is earlier than 13.6
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Check iPadOS version on iPadGo to Settings > General > About on the iPad. Note the version number. Compare to affected range: versions before 13.6.Affected if The iPadOS version shown is earlier than 13.6
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Check tvOS version on Apple TVGo to Settings > General > About > Version on Apple TV. Compare to affected range: versions before 13.4.8.Affected if The tvOS version is earlier than 13.4.8
You are affected if any of your Apple products listed above are running a version lower than the specified patch version, and you process untrusted image files with the affected component.
Generated from the published advisory. Verify against your own configuration.
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 data6.2.87.2011.3
Apply the vendor-supplied security updates: iOS 13.6/iPadOS 13.6, macOS Catalina 10.15.6, tvOS 13.4.8, watchOS 6.2.8, iTunes 12.10.8 for Windows, iCloud for Windows 11.3/7.20. Avoid opening untrusted images from unknown sources until systems are patched.
Fix this in Safari
Scoped from the published advisory
- Consultation3.0 h
- Implementation6.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-9936 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-9936 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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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.
- 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