CVE-2021-39979Public exploit

Hypervisor code execution via unvalidated log metadata

Published Jan 3, 2022 · Updated Aug 4, 2024

Code injection in the HHEE security hypervisor in Huawei HarmonyOS 2.0 allows attackers controlling the kernel to execute code at EL2. The HHEE logging functions trust pointer, offset, and size fields in a shared-memory control structure, letting the kernel redirect hypervisor log writes to chosen EL2 addresses. Exploitation requires kernel control and uses the write primitive to corrupt allocator state, map hypervisor memory writable, and patch hypervisor code.

CVSS severity9.8
Critical
EPSS probability1.05%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Code injection in the HHEE security hypervisor in Huawei HarmonyOS 2.0 allows attackers controlling the kernel to execute code at EL2. The HHEE logging functions trust pointer, offset, and size fields in a shared-memory control structure, letting the kernel redirect hypervisor log writes to chosen EL2 addresses. Exploitation requires kernel control and uses the write primitive to corrupt allocator state, map hypervisor memory writable, and patch hypervisor code.

The record

CVE
CVE-2021-39979
Published
Jan 3, 2022
Updated
Aug 4, 2024
Vendor
Huawei Technologies Co., Ltd.
Product
HarmonyOS
Classifications
CWE-94, T1068
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Jan 3, 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 vectorlocal
Required privilegesadmin

What is affected?

Huawei Technologies Co., Ltd. · HarmonyOSversion=2.0

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
10.0NIST NVDAV:N/AC:L/Au:N/C:C/I:C/A:C

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)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-94Improper Control of Generation of Code ('Code Injection')
T1068Exploitation for Privilege Escalation

Public exploit references

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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