CVE-2021-39629

Local privilege escalation via NFC cleanup race

Published Jan 14, 2022 · Updated Aug 4, 2024

Use-after-free in Android 9 through 12 allows local users to escalate privileges through a race in the NXP NFC transport layer. Concurrent phTmlNfc_Init and phTmlNfc_CleanUp operations can release NFC transport state while the transport thread still accesses it. A local low-privileged process can trigger the race without user interaction and gain higher Android privileges.

CVSS severity7.0
High
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

Use-after-free in Android 9 through 12 allows local users to escalate privileges through a race in the NXP NFC transport layer. Concurrent phTmlNfc_Init and phTmlNfc_CleanUp operations can release NFC transport state while the transport thread still accesses it. A local low-privileged process can trigger the race without user interaction and gain higher Android privileges.

The record

CVE
CVE-2021-39629
Published
Jan 14, 2022
Updated
Aug 4, 2024
Vendor
Google Cloud
Product
Android
Classifications
CWE-362, CWE-416, T1404
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Jan 14, 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=Android-10 Android-11 Android-12 Android-9

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

Google Cloud · Androidversion=Android-10 Android-11 Android-12 Android-9

Published CVSS scores

7.0NIST NVDCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
6.9NIST NVDAV:L/AC:M/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.

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

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CWE-416Use After Free
T1404Exploitation for Privilege Escalation

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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