CVE-2021-39977Network attack vector

Unauthenticated process restart via null pointer dereference

Published Jan 3, 2022 · Updated May 22, 2025

NULL pointer dereference in Huawei HarmonyOS 2.0 allows remote attackers to restart the HwNearbyMain process through network input. Huawei identifies the affected module and fault class but has not published the vulnerable function, input field, protocol, or operation that dereferences the null pointer. The path requires no authentication or user interaction, and the documented consequence is limited to interruption while the process restarts.

CVSS severity7.5
High
EPSS probability0.66%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in Huawei HarmonyOS 2.0 allows remote attackers to restart the HwNearbyMain process through network input. Huawei identifies the affected module and fault class but has not published the vulnerable function, input field, protocol, or operation that dereferences the null pointer. The path requires no authentication or user interaction, and the documented consequence is limited to interruption while the process restarts.

The record

CVE
CVE-2021-39977
Published
Jan 3, 2022
Updated
May 22, 2025
Vendor
Huawei Technologies Co., Ltd.
Product
HarmonyOS
Classifications
CWE-476, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 3, 2022CVE publishedPublication date reported by the CVE source.
  2. May 22, 2025Record 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

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-476NULL Pointer Dereference
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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