Mac Os XOperating system · Apple

CVE-2019-8736

MEDIUM · 6.5 CVSS v3.1 Published 2020-10-27
Fix available
A fix is available. Upgrade to 10.15 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable 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
An input validation issue was addressed with improved input validation. This issue is fixed in macOS Catalina 10.15.1, Security Update 2019-001, and Security Update 2019-006, macOS Catalina 10.15. An attacker in a privileged network position may be able to leak sensitive user information.

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

CVE-2019-8736 is an input validation vulnerability in macOS Catalina that allows an attacker with a privileged network position (e.g., man-in-the-middle) to intercept and leak sensitive user information. The vulnerability stems from insufficient input validation in a system component, and was patched in macOS Catalina 10.15.1 and Security Updates 2019-001/2019-006.

MitigationApply the relevant macOS security update (Catalina 10.15.1, Security Update 2019-001, or Security Update 2019-006) to affected systems. For systems that cannot be updated, implement network-level controls such as TLS inspection or VPN usage to mitigate man-in-the-middle attacks.

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
Mac Os XOperating system
Affected:< 10.15

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
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/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. Identify the installed macOS version
    Run 'sw_vers -productVersion' in Terminal or check System Preferences > About
    Affected if The version reported is below 10.15.1 and the system is running macOS Catalina (10.15.x)
  2. Confirm the base macOS release
    Run 'sw_vers -productVersion' and note the full version string (e.g., 10.15.0, 10.15.1, 10.14.x)
    Affected if The version is 10.15.0 (original Catalina release) and has not received Security Update 2019-001 or 2019-006
  3. Check if security updates are installed
    View System Preferences > Security & Privacy > General to see if 'Security Update 2019-001' or 'Security Update 2019-006' appears under 'Recent Apple Security Updates'
    Affected if Neither Security Update 2019-001 nor Security Update 2019-006 is listed, and the base version is 10.15.0 or earlier
  4. Assess network exposure to man-in-the-middle attacks
    Evaluate whether the system routinely connects to untrusted networks (e.g., public Wi-Fi) where an attacker could intercept network traffic
    Affected if The system is on a version below 10.15.1 AND frequently accesses networks where a privileged network position attacker could intercept traffic

A system is affected if it runs macOS Catalina (10.15.x) at version 10.15.0 without Security Update 2019-001 or 2019-006 installed, and operates in network environments where a man-in-the-middle attack is plausible.

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 10.15 or later
Fixed in 10.15
Interim mitigation

Apply the relevant macOS security update (Catalina 10.15.1, Security Update 2019-001, or Security Update 2019-006) to affected systems. For systems that cannot be updated, implement network-level controls such as TLS inspection or VPN usage to mitigate man-in-the-middle attacks.

Fix this in Mac Os X 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
Get the upgrade done

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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2019-8736 — 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-2019-8736 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