CVE-2021-34143: The Bluetooth Classic implementation in the Zhuhai Jieli AC6366C_DEMO_V1.0 does not properly handle the recept

Routine

MEDIUM 6.5MITIGATE

CVE-2021-34143 is a medium-severity flaw (CVSS 6.5) affecting fw-ac63 bt sdk. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The Bluetooth Classic implementation in the Zhuhai Jieli AC6366C_DEMO_V1.0 does not properly handle the reception of continuous unsolicited LMP responses, allowing attackers in radio range to trigger a denial of service (deadlock) of the device by flooding it with LMP_AU_Rand packets after paging procedure. User intervention is required to restart the device.

Why this priority

No elevated risk signals yet

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Adjacent network
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 45%)
CISA exploited list	No
Published	2021-09-07
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: zh-jieli

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-09-07 07:15 UTCPublished CVE record published
2026-06-17 03:55 UTCUpdated Record last modified

zh-jieli fw-ac63 bt sdk MITIGATE

Affected: 1.0.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.0.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-34143?

fw-ac63 bt sdk: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-34143 being exploited?

CVE-2021-34143 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-34143 affect?

CVE-2021-34143 affects fw-ac63 bt sdk. Severity is medium (CVSS 6.5). The Bluetooth Classic implementation in the Zhuhai Jieli AC6366C_DEMO_V1.0 does not properly handle the reception of continuous unsolicited LMP responses, allowing attackers in radio range to trigger a denial of service (deadlock) of the de

How urgent is CVE-2021-34143?

Priority 36/100. No elevated risk signals yet.

Software pages

Bluetooth vulnerabilities

Related CVEs

CVE-2021-34144 MEDIUM 6.5 UPGRADE The Bluetooth Classic implementation in the Zhuhai Jieli AC6366C BT SDK through 0.9.1 does not properly handle

References

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