CVE-2020-3870
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 read was addressed with improved input validation. This issue is fixed in iOS 13.3.1 and iPadOS 13.3.1, macOS Catalina 10.15.3, tvOS 13.3.1, watchOS 6.1.2. 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 confidenceAn out-of-bounds read vulnerability in Apple's image processing frameworks across iOS, iPadOS, macOS, tvOS, and watchOS. The vulnerability is triggered when processing a maliciously crafted image file, which can lead to arbitrary code execution due to improper input validation.
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< 13.3.1< 13.3.1< 10.15.3< 13.3.1< 6.1.2CVSS 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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Identify the Apple platform runningDetermine if the system is iOS, iPadOS, macOS, tvOS, or watchOS. On iOS/iPadOS, check Settings > General > About. On macOS, check About This Mac. On tvOS, check Settings > General > About. On watchOS, check via the Watch app on paired iPhone: My Watch > General > About.Affected if The platform is not one of the five listed (iOS, iPadOS, macOS, tvOS, watchOS)
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Check iOS or iPadOS versionOn the device, go to Settings > General > About and note the Version number (for example, 13.3, 13.2.3). Compare against the affected range: versions before 13.3.1 are vulnerable.Affected if The iOS or iPadOS version is lower than 13.3.1
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Check macOS versionClick the Apple menu > About This Mac. Note the version number (for example, 10.15.2, 10.15.1). Compare against the affected range: versions before 10.15.3 are vulnerable.Affected if The macOS version is lower than 10.15.3
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Check tvOS versionOn Apple TV, go to Settings > General > About > Version. Compare against the affected range: versions before 13.3.1 are vulnerable.Affected if The tvOS version is lower than 13.3.1
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Check watchOS versionOpen the Watch app on paired iPhone, go to My Watch > General > About, and note the watchOS version. Compare against the affected range: versions before 6.1.2 are vulnerable.Affected if The watchOS version is lower than 6.1.2
The system is affected if it runs any unpatched version of iOS, iPadOS, macOS, tvOS, or watchOS within the affected version ranges (iOS/iPadOS/tvOS < 13.3.1, macOS < 10.15.3, watchOS < 6.1.2).
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 data6.1.210.15.313.3.1
Apply the vendor-supplied security updates: iOS 13.3.1 and later, iPadOS 13.3.1 and later, macOS Catalina 10.15.3 and later, tvOS 13.3.1 and later, or watchOS 6.1.2 and later.
- Consultation2.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-3870 — 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-2020-3870 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
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