CVE-2021-39647

Local TEE information disclosure via improper locking

Published Dec 15, 2021 · Updated Aug 4, 2024

Information disclosure in the Android kernel bootloader allows local users with System privileges to read TEE information. The mon_smc_load_sp routine can reinitialize the TEE because it does not properly lock the initialization operation. Exploitation requires local System execution privileges and no user interaction, and the disclosed data is confined to TEE information.

CVSS severity4.4
Medium
EPSS probability0.09%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in the Android kernel bootloader allows local users with System privileges to read TEE information. The mon_smc_load_sp routine can reinitialize the TEE because it does not properly lock the initialization operation. Exploitation requires local System execution privileges and no user interaction, and the disclosed data is confined to TEE information.

The record

CVE
CVE-2021-39647
Published
Dec 15, 2021
Updated
Aug 4, 2024
Vendor
Google Cloud
Product
Android
Classifications
CWE-667
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Dec 15, 2021CVE 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?

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  1. Affected versionversion=Android kernel

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Google Cloud · Androidversion=Android kernel

Published CVSS scores

2.1NIST NVDAV:L/AC:L/Au:N/C:P/I:N/A:N
4.4NIST NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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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 exploitUnconfirmed

Weakness, pattern, technique

CWE-667Improper Locking

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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