dbcve.org
EmuiOperating system · Huawei

CVE-2021-40017

CRITICAL · 9.8 CVSS v3.1 Published 2022-09-16
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
The HW_KEYMASTER module lacks the validity check of the key format. Successful exploitation of this vulnerability may result in out-of-bounds memory access.

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

The HW_KEYMASTER hardware security module does not validate key format before processing, allowing malformed keys to trigger out-of-bounds memory access. This is a memory safety vulnerability in a critical cryptographic key management component.

MitigationApply vendor-supplied firmware/patch updates for the affected device. Coordinate with device OEM/vendor to obtain and deploy the corrected keymaster module. No user-facing workarounds exist for hardware-level vulnerabilities.

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:= 11.0.1= 12.0.0
HarmonyosOperating system
Affected:= 2.0

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 the device OS and version
    Check system settings > About Phone to find the EMUI or HarmonyOS version number
    Affected if The device runs EMUI 11.0.1, EMUI 12.0.0, or HarmonyOS 2.0
  2. Confirm the HW_KEYMASTER module is present
    Check /vendor/lib/hw/ or /system/lib/hw/ directories for keymaster*.so or keymaster_v*.so files, or review /proc/keys and hardware keystore status via keystore -v
    Affected if The device has a hardware-backed keymaster module from Huawei
  3. Verify the keystore service is enabled
    Check if keymaster service is running via 'dumpsys keymaster' or 'getprop ro.hardware.keystore'
    Affected if The keystore/keymaster service is active and processes cryptographic keys
  4. Check firmware build number
    Review build.prop or settings for the full firmware build (such as EMUI 11.0.1 build XXXX)
    Affected if Build number corresponds to an unpatched EMUI 11.0.1/12.0.0 or HarmonyOS 2.0 release

The device is affected if it runs EMUI 11.0.1, EMUI 12.0.0, or HarmonyOS 2.0 and contains the Huawei HW_KEYMASTER hardware security module.

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/patch updates for the affected device. Coordinate with device OEM/vendor to obtain and deploy the corrected keymaster module. No user-facing workarounds exist for hardware-level vulnerabilities.

Fix this in Emui Scoped from the published advisory
  • Consultation12.0 h
  • Implementation4.0 h
  • Testing16.0 h
  • Review / QA8.0 h
40.0 hours of engineering $6,960
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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-2021-40017 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