Iphone OsOperating system · Apple

CVE-2019-8531

CRITICAL · 9.8 CVSS v3.1 Published 2020-10-27
Fix available
A fix is available. Upgrade to 5.2 / 10.14.4 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

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 validation issue existed in Trust Anchor Management. This issue was addressed with improved validation. This issue is fixed in watchOS 5.2, macOS Mojave 10.14.4, Security Update 2019-002 High Sierra, Security Update 2019-002 Sierra, iOS 12.2. An untrusted radius server certificate may be trusted.

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 validation bypass in Trust Anchor Management allows untrusted RADIUS server certificates to be incorrectly trusted, potentially enabling man-in-the-middle attacks on RADIUS authentication by accepting malicious certificates as valid.

MitigationApply the relevant vendor patch: iOS 12.2, watchOS 5.2, macOS Mojave 10.14.4, or Security Update 2019-002 for High Sierra/Sierra.

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
Iphone OsOperating system
Affected:< 12.2
Mac Os XOperating system
Affected:< 10.14.4
WatchosOperating system
Affected:< 5.2

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
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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. Check iOS version on iPhone
    Go to Settings > General > About and note the Version number (e.g., 12.1.x)
    Affected if Version is below 12.2 and the device uses RADIUS authentication for network access
  2. Check macOS version
    Click Apple menu > About This Mac and note the macOS version (e.g., 10.14.3)
    Affected if Version is below 10.14.4 and the Mac uses RADIUS authentication for network login or 802.1X
  3. Check watchOS version on Apple Watch
    Open the Watch app on paired iPhone, go to General > About and note the watchOS version
    Affected if Version is below 5.2 and the Apple Watch authenticates via RADIUS-enabled networks
  4. Verify RADIUS authentication is configured
    On iOS: check for RADIUS client profiles in Settings > General > Profile. On macOS: check System Preferences > Network > Advanced > 802.1X for enabled RADIUS servers
    Affected if A RADIUS server configuration exists and the OS version is in the affected range

You are affected if your device runs an unpatched iOS below 12.2, macOS below 10.14.4, or watchOS below 5.2 AND has RADIUS authentication configured for network or system access.

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 5.2 / 10.14.4 / 12.2 or later
Fixed in 5.210.14.412.2
Interim mitigation

Apply the relevant vendor patch: iOS 12.2, watchOS 5.2, macOS Mojave 10.14.4, or Security Update 2019-002 for High Sierra/Sierra.

Recommended fix High confidence

iOS 12.2+ | macOS 10.14.4+ (or Security Update 2019-002 for older macOS) | watchOS 5.2+

  1. Identify the affected Apple device (iPhone, Mac, or Apple Watch)
  2. For iPhone/iPad: Go to Settings > General > Software Update and upgrade to iOS 12.2 or later
  3. For Mac: Go to System Preferences > Software Update and upgrade to macOS Mojave 10.14.4 or later, or apply Security Update 2019-002 for High Sierra/Sierra
  4. For Apple Watch: Open the Watch app on paired iPhone, go to General > Software Update, and upgrade to watchOS 5.2 or later
  5. After updating, verify the new version is installed
Caveat Standard OS update considerations - ensure backup of important data before updating, and verify app compatibility with the new OS version

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

Fix this in Iphone Os 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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Scan for this in your stack

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dbcve dependency scanner

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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-2019-8531 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