CVE-2021-31611

Name: CVE-2021-31611
Creator: NVD / NIST
Published: 2021-09-07T07:15:07.043+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.7/10EPSS 0.35%

Last modified Jun 17, 2026

CVE-2021-31611 is a medium-severity vulnerability rated 5.7/10 on the CVSS scale. The Bluetooth Classic implementation on Zhuhai Jieli AC690X and AC692X devices does not properly handle an out-of-order LMP Setup procedure that is followed by a malformed LMP packet, allowing attackers in radio range to deadlock a device via a crafted LMP packet. The user needs to manually reboot the device to restore communication.. EPSS estimates a 0.35% chance of exploitation in the next 30 days.

Description

The Bluetooth Classic implementation on Zhuhai Jieli AC690X and AC692X devices does not properly handle an out-of-order LMP Setup procedure that is followed by a malformed LMP packet, allowing attackers in radio range to deadlock a device via a crafted LMP packet. The user needs to manually reboot the device to restore communication.

Metrics

CVSS 3.1

5.7/10

CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

EPSS Probability

0.35%

27.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-667

Affected Software

Vendor	Product	Versions
Zh-Jieli	Ac6901 Firmware	All versions
Zh-Jieli	Ac6925 Firmware	All versions
Zh-Jieli	Ac6926 Firmware	All versions
Zh-Jieli	Ac6928 Firmware	All versions
Zh-Jieli	Ac6921 Firmware	All versions

References

http://www.zh-jieli.com/product/68-cn.htmlVendor Advisory
https://dl.packetstormsecurity.net/papers/general/braktooth.pdfBroken Link
https://launchstudio.bluetooth.com/ListingDetails/19746Third Party Advisory
https://launchstudio.bluetooth.com/ListingDetails/58628Third Party Advisory
http://www.zh-jieli.com/product/68-cn.htmlVendor Advisory
https://dl.packetstormsecurity.net/papers/general/braktooth.pdfBroken Link
https://launchstudio.bluetooth.com/ListingDetails/19746Third Party Advisory
https://launchstudio.bluetooth.com/ListingDetails/58628Third Party Advisory

Timeline

Published: Sep 7, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-31611?

How severe is CVE-2021-31611?

CVE-2021-31611 has a CVSS score of 5.7/10 (MEDIUM severity). The EPSS model estimates a 0.35% probability of exploitation in the next 30 days.

How do I fix CVE-2021-31611?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-31611?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST