EmuiOperating system · Huawei

CVE-2020-9140

CRITICAL · 9.8 CVSS v3.1 Published 2021-01-13
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
There is a vulnerability with buffer access with incorrect length value in some Huawei Smartphone.Unauthorized users may trigger code execution when a buffer overflow occurs.

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 Huawei Smartphone firmware where incorrect length values are used during buffer access operations. This allows unauthorized users to overflow buffers and achieve code execution.

MitigationApply vendor-supplied firmware patches for affected Huawei smartphone models. Until patches are available, minimize exposure by restricting network access and avoiding untrusted applications.

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
EmuiOperating system
Affected:= 9.1.0= 9.1.1= 10.0.0= 10.1.0= 10.1.1= 11.0.0
Magic UiOperating system
Affected:= 2.1.1= 3.0.0= 3.1.0= 3.1.1= 4.0.0

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. Identify your Huawei smartphone firmware version
    Navigate to Settings > System > About Phone (or Settings > About Phone) and locate the 'Version' or 'Build Number' field. Record the exact EMUI or Magic UI version number displayed.
    Affected if The displayed version matches one of the following: EMUI 9.1.0, 9.1.1, 10.0.0, 10.1.0, 10.1.1, 11.0.0, or Magic UI 2.1.1, 3.0.0, 3.1.0, 3.1.1, 4.0.0
  2. Confirm the UI layer type
    In the About Phone settings, determine whether your device runs EMUI or Magic UI. This distinction is important as these are separate version tracks with their own affected ranges.
    Affected if The device runs EMUI and the version is any of the six listed versions, OR the device runs Magic UI and the version is any of the five listed versions
  3. Verify the build matches exact affected versions
    Compare your recorded version string character-for-character against the affected versions list. Note that partial matches (e.g., 10.1.0 matching a hypothetical 10.1.0.1) require clarification from Huawei documentation.
    Affected if The version string exactly matches any version in the affected products list (the equals signs in the CVE indicate exact version matches, not ranges)
  4. Check if device is still receiving updates
    In Settings > System > Software Update, check whether your device is still listed as receiving security patches. Devices on these older versions may be past end-of-support.
    Affected if The device is on an affected version and no longer appears in Huawei's current security update schedule

A user is affected if their Huawei smartphone runs EMUI version 9.1.0, 9.1.1, 10.0.0, 10.1.0, 10.1.1, or 11.0.0, or Magic UI version 2.1.1, 3.0.0, 3.1.0, 3.1.1, or 4.0.0, as these exact versions contain the buffer overflow vulnerability in firmware buffer access operations.

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 vendor-supplied firmware patches for affected Huawei smartphone models. Until patches are available, minimize exposure by restricting network access and avoiding untrusted applications.

Fix this in Emui Scoped from the published advisory
  • Consultation8.0 h
  • Implementation24.0 h
  • Testing16.0 h
  • Review / QA12.0 h
60.0 hours of engineering $10,480
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2020-9140 — 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-2020-9140 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