CVE-2021-39774

Local denial of service via Bluetooth bounds check

Published Mar 30, 2022 · Updated Aug 4, 2024

Denial of service in Android 12L Bluetooth in Google Cloud Android allows local users to cause service interruption via malformed Bluetooth data. The Bluetooth implementation reads beyond a buffer because a required bounds check is missing when processing attacker-controlled input. Exploitation requires local access to the Bluetooth interface, needs no additional execution privileges or user interaction, and the documented consequence is denial of service without stated data disclosure or code execution.

CVSS severity5.5
Medium
EPSS probability0.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Android 12L Bluetooth in Google Cloud Android allows local users to cause service interruption via malformed Bluetooth data. The Bluetooth implementation reads beyond a buffer because a required bounds check is missing when processing attacker-controlled input. Exploitation requires local access to the Bluetooth interface, needs no additional execution privileges or user interaction, and the documented consequence is denial of service without stated data disclosure or code execution.

The record

CVE
CVE-2021-39774
Published
Mar 30, 2022
Updated
Aug 4, 2024
Vendor
Google Cloud
Product
Android
Classifications
CWE-125, T1499
Attack vector
local
Privileges
authenticated

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?

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  1. Affected versionversion=Android-12L

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Google Cloud · Androidversion=Android-12L

Published CVSS scores

2.1NVDAV:L/AC:L/Au:N/C:N/I:N/A:P
5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1499Endpoint Denial of Service

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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