CVE-2021-40021Network attack vector

Confidentiality loss via eID buffer write

Published Jan 7, 2022 · Updated Aug 4, 2024

Out-of-bounds write in Huawei HarmonyOS 2.0 allows remote attackers to affect confidentiality via the eID module. The eID module writes beyond a valid memory buffer when processing attacker-controlled input, corrupting adjacent memory. NVD rates the issue as network-reachable without authentication; exploitation can disclose confidential data, while integrity and availability effects are not established.

CVSS severity7.5
High
EPSS probability0.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in Huawei HarmonyOS 2.0 allows remote attackers to affect confidentiality via the eID module. The eID module writes beyond a valid memory buffer when processing attacker-controlled input, corrupting adjacent memory. NVD rates the issue as network-reachable without authentication; exploitation can disclose confidential data, while integrity and availability effects are not established.

The record

CVE
CVE-2021-40021
Published
Jan 7, 2022
Updated
Aug 4, 2024
Vendor
Huawei Technologies Co., Ltd.
Product
HarmonyOS
Classifications
CWE-787
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 7, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Huawei Technologies Co., Ltd. · HarmonyOSversion=2.0

Published CVSS scores

5.0NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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