Iphone OsOperating system · Apple

CVE-2018-4436

HIGH · 7.5 CVSS v3.0 Published 2019-04-03
Fix available
A fix is available. Upgrade to 5.1.2 / 12.1.1 or later.
See remediation →
84/100
Remediation priority · High
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 certificate validation issue existed in configuration profiles. This was addressed with additional checks. This issue affected versions prior to iOS 12.1.1, tvOS 12.1.1, watchOS 5.1.2.

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 certificate validation flaw existed in Apple configuration profiles used by iOS, tvOS, and watchOS. The vulnerability allowed improper or absent certificate validation, potentially enabling man-in-the-middle attacks or acceptance of malicious certificates when devices installed configuration profiles.

MitigationUpdate affected devices to iOS 12.1.1 or later, tvOS 12.1.1 or later, and watchOS 5.1.2 or later. For enterprise environments, deploy updates via MDM or ensure users apply system updates.

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:< 12.1.1
TvosOperating system
Affected:< 12.1.1
WatchosOperating system
Affected:< 5.1.2

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
None
Integrity
High
Availability
None

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

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 or iPad
    Go to Settings > General > About > Version, or use Apple Configurator 2 or MDM to query device OS version
    Affected if Version is below 12.1.1 and configuration profiles are installed on the device
  2. Check tvOS version on Apple TV
    Go to Settings > General > About > Version, or query through MDM/enrollment profile
    Affected if Version is below 12.1.1 and configuration profiles are installed on the device
  3. Check watchOS version on Apple Watch
    Go to Settings > General > About > Version on the paired iPhone in the Watch app, or query through MDM
    Affected if Version is below 5.1.2 and configuration profiles are installed on the device
  4. Identify installed configuration profiles
    On iOS: Settings > General > Profile (or Profiles & Device Management). On tvOS: Settings > General > Profiles. On watchOS: Check via paired iPhone Watch app > General > Profile
    Affected if Any configuration profile is installed on a device running an affected OS version
  5. Review MDM-enrolled devices for OS versions
    Query MDM server (such as Apple Device Enrollment Program or third-party MDM) for device OS inventory reports
    Affected if MDM shows devices enrolled with iOS < 12.1.1, tvOS < 12.1.1, or watchOS < 5.1.2 that have configuration profiles assigned

A device is affected if it runs iOS, tvOS, or watchOS versions below the fixed releases AND has configuration profiles installed, as the certificate validation flaw only applies when configuration profiles are used.

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 5.1.2 / 12.1.1 or later
Fixed in 5.1.212.1.1
Interim mitigation

Update affected devices to iOS 12.1.1 or later, tvOS 12.1.1 or later, and watchOS 5.1.2 or later. For enterprise environments, deploy updates via MDM or ensure users apply system updates.

Fix this in Iphone Os Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
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Scan for this in your stack

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dbcve dependency scanner

Check whether your project pulls in CVE-2018-4436 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2018-4436 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