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AndroidOperating system · Google

CVE-2018-21049

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 N(7.x) and O(8.X) (Exynos chipsets) software. There is an arbitrary memory write in a Trustlet because a secure driver allows access to sensitive APIs. The Samsung ID is SVE-2018-12881 (November 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 · high confidence

A critical arbitrary memory write vulnerability exists in the Trustlet (Trusted Execution Environment component) on Samsung mobile devices with Exynos chipsets running Android N (7.x) and O (8.X). A secure driver improperly exposes sensitive APIs, allowing an attacker to write to arbitrary memory locations in the trusted zone, potentially achieving code execution with the highest privileges and bypassing hardware-backed security mechanisms.

MitigationApply Samsung firmware updates (SVE-2018-12881) to affected devices. Organizations should inventory Exynos-based Samsung devices running Android N/O and prioritize patch deployment through enterprise mobile management or carrier 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
AndroidOperating system
Affected:= 7.0= 7.1.0= 7.1.1= 7.1.2= 8.0= 8.1

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. Identify device manufacturer and chipset
    Check if the device is a Samsung model using an Exynos chipset. This information is typically available in device settings under 'About phone' or through 'getprop' commands querying 'ro.product.brand' and 'ro.hardware' or 'ro.chipname'.
    Affected if The device is a Samsung device with an Exynos (or Samsung Exynos) chipset.
  2. Verify Android version
    Check the Android OS version on the device. On the device, go to Settings > About phone > Android version, or use 'getprop ro.build.version.release'. Compare the version against the affected list.
    Affected if The Android version is exactly 7.0, 7.1.0, 7.1.1, 7.1.2, 8.0, or 8.1.
  3. Confirm Trustlet/TEE is active
    Verify that the Trusted Execution Environment (TEE) component is present and active on the device. This is typically enabled by default on Exynos devices. Check via 'dmesg' for TEE-related kernel messages or examine /dev/tee* device nodes.
    Affected if The device has an active TEE/Trustlet component (this is the default state on affected Exynos devices).

If the device is a Samsung model with an Exynos chipset running Android 7.0, 7.1.0-7.1.2, or 8.0-8.1 with TEE enabled, the device is likely affected by this arbitrary memory write vulnerability in the Trustlet secure driver.

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

Apply Samsung firmware updates (SVE-2018-12881) to affected devices. Organizations should inventory Exynos-based Samsung devices running Android N/O and prioritize patch deployment through enterprise mobile management or carrier updates.

Recommended fix Moderate confidence

Samsung security patch released November 2018 or later (specific patch level varies by device model)

  1. Check your Samsung device model and current Android/security patch version in Settings > About phone > Software information
  2. Visit the Samsung Security Portal at security.samsungmobile.com and look for SVE-2018-12881 to identify the specific security patch level that contains the fix
  3. Apply the latest available Samsung security update for your device model - go to Settings > Software update > Download and install
  4. If no update is available from Samsung for your specific device model, consider replacing the device as this is a critical vulnerability with arbitrary memory write capability

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

Fix this in Android Scoped from the published advisory
  • Consultation8.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,920
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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-2018-21049 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