EmuiOperating system · Huawei

CVE-2021-22379

HIGH · 7.5 CVSS v3.1 Published 2021-08-02
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
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 an Integer Underflow (Wrap or Wraparound) Vulnerability in Huawei Smartphone.Successful exploitation of this vulnerability may cause DoS of Samgr.

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

Integer underflow vulnerability in Huawei smartphone's Samgr service allows an attacker to cause a denial of service by wrapping an integer value below its minimum representable value, potentially leading to service crash or unexpected behavior.

MitigationApply vendor-supplied firmware/security patch updates for Huawei smartphones; until patch is available, monitor for unusual service behavior and restrict exposure to untrusted inputs.

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:= 11.0.0
Magic UiOperating system
Affected:= 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
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 the smartphone OS
    Determine if the device runs Huawei Emui or Magic UI. This can be done through device settings under 'About Phone' or via MDM inventory if managed.
    Affected if The device is running either Emui or Magic UI operating system
  2. Check the installed Emui version
    Navigate to Settings > About Phone on Huawei devices running Emui, and note the EMUI version number displayed.
    Affected if The installed Emui version is exactly 11.0.0
  3. Check the installed Magic UI version
    Navigate to Settings > About Phone on Huawei devices running Magic UI, and note the version number displayed.
    Affected if The installed Magic UI version is exactly 4.0.0
  4. Verify the Samgr service is present
    Check if the Samgr service is running or available on the device. This may require access to system service information through developer options, ADB shell, or MDM diagnostic tools.
    Affected if The Samgr service is present and running on the device with an affected OS version
  5. Monitor for Samgr service anomalies
    Review device logs or system reports for any Samgr service crashes, restarts, or unexpected behavior patterns that may indicate exploitation of this integer underflow vulnerability.
    Affected if The Samgr service exhibits crashes, unexpected termination, or abnormal behavior on an affected version

A device is affected if it runs Emui version 11.0.0 or Magic UI version 4.0.0 and has the Samgr service active, as the integer underflow in this service can cause denial of service.

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/security patch updates for Huawei smartphones; until patch is available, monitor for unusual service behavior and restrict exposure to untrusted inputs.

Fix this in Emui Scoped from the published advisory
  • Consultation4.0 h
  • Testing6.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,060
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-22379 — 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-2021-22379 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