dbcve.org
AndroidOperating system · Google

CVE-2018-21054

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), N(7.x) and O(8.x) except exynos9610/9820 in all Platforms, M(6.0) except MSM8909 SC77xx/9830 exynos3470/5420, N(7.0) except MSM8939, N(7.1) except MSM8996 SDM6xx/M6737T software. There is an integer underflow with a resultant buffer overflow in eCryptFS. The Samsung ID is SVE-2017-11857 (September 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

Integer underflow vulnerability in eCryptFS filesystem on Samsung mobile devices running Android M(6.0), N(7.x), and O(8.x) leads to buffer overflow. The flaw exists in the kernel-level encryption filesystem component and allows memory corruption that could enable arbitrary code execution or privilege escalation.

MitigationApply Samsung security firmware updates (SVE-2017-11857) to patched Android versions; no user-facing configuration change can remediate this kernel-level filesystem vulnerability.

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= 7.0= 7.1.0= 7.1.1= 7.1.2= 8.0= 8.1= 7.1

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. Confirm device is a Samsung mobile device
    Check the device manufacturer via 'getprop ro.product.manufacturer' or 'getprop ro.product.brand' in ADB/shell
    Affected if The manufacturer or brand is not Samsung (this vulnerability specifically affects Samsung mobile devices)
  2. Check Android version
    Run 'getprop ro.build.version.release' in ADB/shell to retrieve the Android version
    Affected if The version is 6.0, 7.0, 7.1, 7.1.0, 7.1.1, 7.1.2, 8.0, or 8.1 (the specific versions listed as affected)
  3. Verify eCryptFS filesystem is in use
    Check mounted filesystems for eCryptFS by running 'mount' in ADB/shell and looking for 'ecryptfs' in the output, or check /proc/mounts
    Affected if eCryptFS is actively mounted (the vulnerability exists in the kernel-level eCryptFS component, so the filesystem must be in use for the flaw to be exploitable)
  4. Check for Samsung firmware version
    Run 'getprop ro.build.version.security_patch' or check the Samsung security patch level via 'getprop ro.security.patch.level'
    Affected if The security patch level is older than the SVE-2017-11857 fix (indicating unpatched firmware)

The device is affected if it is a Samsung mobile device running Android 6.0 through 8.1 with eCryptFS mounted and no security firmware update applied.

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 security firmware updates (SVE-2017-11857) to patched Android versions; no user-facing configuration change can remediate this kernel-level filesystem vulnerability.

Recommended fix Moderate confidence
  1. Check the device for available OTA (Over-The-Air) system updates in Settings > About device > Software update
  2. Ensure the device is updated to the latest Samsung security patch level available for that model
  3. Verify the security patch date in Settings > About device > Software information > Security patch level is September 2018 or later
  4. If no update is available, contact the device carrier or Samsung support for patch availability

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

Fix this in Android Scoped from the published advisory
  • Consultation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,280
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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-2018-21054 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