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AndroidOperating system · Google

CVE-2018-21066

CRITICAL · 9.8 CVSS v3.1 Published 2020-04-08
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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
An issue was discovered on Samsung mobile devices with M(6.0) (Exynos or MediaTek chipsets) software. There is a buffer overflow in a Trustlet that can cause memory corruption. The Samsung ID is SVE-2018-11599 (July 2018).

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 · moderate confidence

A buffer overflow vulnerability exists in a Trustlet (trusted execution environment component) on Samsung mobile devices running Android M (6.0) with Exynos or MediaTek chipsets. The overflow can cause memory corruption, potentially allowing privilege escalation or arbitrary code execution within the trusted execution environment.

MitigationApply the July 2018 Samsung security patch or update to a newer Android version. For devices that have reached end-of-life and cannot receive updates, consider replacement with a currently supported device.

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
AndroidOperating system
Affected:= 6.0

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 Android version
    Go to Settings > About Phone > Android version, or run 'getprop ro.build.version.release' via ADB
    Affected if Version equals 6.0 (Android Marshmallow)
  2. Verify device is Samsung
    Check Settings > About Phone > Manufacturer, or run 'getprop ro.product.manufacturer' via ADB
    Affected if Manufacturer is Samsung
  3. Identify chipset vendor
    Check Settings > About Phone > CPU/chipset details, or run 'getprop ro.hardware' via ADB
    Affected if Chipset is Exynos or MediaTek
  4. Confirm Trustlet/TEE is active
    Check if TEE subsystem is present: run 'ls /dev/tee*' or 'getprop ro.tee.enabled' via ADB, or check /sys/class/misc/ for tee devices
    Affected if Trusted Execution Environment component is present and enabled on the device

All four conditions must be true for the device to be affected: Android 6.0, Samsung device, Exynos or MediaTek chipset, and TEE/Trustlet enabled.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the July 2018 Samsung security patch or update to a newer Android version. For devices that have reached end-of-life and cannot receive updates, consider replacement with a currently supported device.

Fix this in Android Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
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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-2018-21066 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