CVE-2021-39772

Local privilege escalation via unchecked A2DP control access

Published Mar 30, 2022 · Updated Aug 4, 2024

Privilege escalation in the Bluetooth system component of Google Cloud Android 12L allows local users to control the A2DP audio switch. A missing permission check lets an unprivileged caller access the A2DP audio control switch, but Google has not disclosed the responsible function or call path. Exploitation requires local execution on an affected device, needs no user interaction or additional execution privileges, and grants control beyond the caller's assigned permissions.

CVSS severity8.8
High
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Privilege escalation in the Bluetooth system component of Google Cloud Android 12L allows local users to control the A2DP audio switch. A missing permission check lets an unprivileged caller access the A2DP audio control switch, but Google has not disclosed the responsible function or call path. Exploitation requires local execution on an affected device, needs no user interaction or additional execution privileges, and grants control beyond the caller's assigned permissions.

The record

CVE
CVE-2021-39772
Published
Mar 30, 2022
Updated
Aug 4, 2024
Vendor
Google Cloud
Product
Android
Classifications
CWE-269, T1068
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 30, 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-12L

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Google Cloud · Androidversion=Android-12L

Published CVSS scores

5.8NIST NVDAV:A/AC:L/Au:N/C:P/I:P/A:P
8.8NIST NVDCVSS:3.1/AV:A/AC:L/PR:N/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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-269Improper Privilege Management
T1068Exploitation 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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