CVE-2021-34143Public exploit

Bluetooth deadlock via unsolicited LMP_AU_Rand flooding

Published Sep 7, 2021 · Updated Aug 4, 2024

Denial of service in Zhuhai Jieli AC6366C_DEMO_V1.0 allows physically proximate attackers to deadlock Bluetooth via LMP_AU_Rand flooding. The Bluetooth Classic link manager accepts continuous unsolicited LMP_AU_Rand responses after paging, and the flood triggers a heap overflow in firmware. Radio range and the target BDAddress are required; the deadlock interrupts Bluetooth service until a user manually restarts the device.

CVSS severity6.5
Medium
EPSS probability0.74%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Denial of service in Zhuhai Jieli AC6366C_DEMO_V1.0 allows physically proximate attackers to deadlock Bluetooth via LMP_AU_Rand flooding. The Bluetooth Classic link manager accepts continuous unsolicited LMP_AU_Rand responses after paging, and the flood triggers a heap overflow in firmware. Radio range and the target BDAddress are required; the deadlock interrupts Bluetooth service until a user manually restarts the device.

The record

CVE
CVE-2021-34143
Published
Sep 7, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1499.002
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 7, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.1NIST NVDAV:A/AC:L/Au:N/C:N/I:N/A:C
6.5NIST NVDCVSS:3.1/AV:A/AC:L/PR:N/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.

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 exploitPublished

Weakness, pattern, technique

T1499.002Service Exhaustion Flood

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo