CVE-2021-39674

Local privilege escalation via invalidated Bluetooth record

Published Feb 11, 2022 · Updated Aug 4, 2024

Use-after-free in Android 10 through 12 Bluetooth security handling allows local users to escalate privileges without user interaction. btm_sec_connected and btm_sec_disconnected obtain a device-record pointer before btm_acl_resubmit_page, which can invalidate the record before later dereferences. Exploitation requires user execution privileges on the device and can grant higher privileges without further user interaction.

CVSS severity7.8
High
EPSS probability0.15%
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 10 through 12 Bluetooth security handling allows local users to escalate privileges without user interaction. btm_sec_connected and btm_sec_disconnected obtain a device-record pointer before btm_acl_resubmit_page, which can invalidate the record before later dereferences. Exploitation requires user execution privileges on the device and can grant higher privileges without further user interaction.

The record

CVE
CVE-2021-39674
Published
Feb 11, 2022
Updated
Aug 4, 2024
Vendor
Google Cloud
Product
Android
Classifications
CWE-416, T1404
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 11, 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

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

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

Published CVSS scores

7.2NIST NVDAV:L/AC:L/Au:N/C:C/I:C/A:C
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1404Exploitation for Privilege Escalation

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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