CVE-2021-31785

Name: CVE-2021-31785
Creator: NVD / NIST
Published: 2021-09-07T07:15:07.143+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 0.43%

Last modified Jun 17, 2026

CVE-2021-31785 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. The Bluetooth Classic implementation on Actions ATS2815 and ATS2819 chipsets does not properly handle the reception of multiple LMP_host_connection_req packets, allowing attackers in radio range to trigger a denial of service (deadlock) of the device via crafted LMP packets. Manual user intervention is required to restart the device and restore Bluetooth communication.. EPSS estimates a 0.43% chance of exploitation in the next 30 days.

Description

The Bluetooth Classic implementation on Actions ATS2815 and ATS2819 chipsets does not properly handle the reception of multiple LMP_host_connection_req packets, allowing attackers in radio range to trigger a denial of service (deadlock) of the device via crafted LMP packets. Manual user intervention is required to restart the device and restore Bluetooth communication.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

0.43%

34.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-667

Affected Software

Vendor	Product	Versions
Actions-Semi	Ats2819p Firmware	All versions
Actions-Semi	Ats2815 Firmware	All versions
Actions-Semi	Ats2819 Firmware	All versions
Actions-Semi	Ats2819s Firmware	All versions
Actions-Semi	Ats2819t Firmware	All versions

References

https://dl.packetstormsecurity.net/papers/general/braktooth.pdfTechnical Description, Third Party Advisory
https://launchstudio.bluetooth.com/ListingDetails/76427Third Party Advisory
https://www.actions-semi.com/index.php?id=3581&siteId=4Broken Link, Vendor Advisory
https://dl.packetstormsecurity.net/papers/general/braktooth.pdfTechnical Description, Third Party Advisory
https://launchstudio.bluetooth.com/ListingDetails/76427Third Party Advisory
https://www.actions-semi.com/index.php?id=3581&siteId=4Broken Link, Vendor Advisory

Timeline

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

Frequently Asked Questions

What is CVE-2021-31785?

How severe is CVE-2021-31785?

CVE-2021-31785 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.43% probability of exploitation in the next 30 days.

How do I fix CVE-2021-31785?

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-2021-31785?

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

Scan your code now

Source: NVD / NIST