CVE-2021-31785

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-09-07 · updated 2026-06-17
Weakness: CWE-667

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.

Affected products

Actions-Semi Ats2815 Firmware: all versions
Actions-Semi Ats2819 Firmware: all versions
Actions-Semi Ats2819P Firmware: all versions
Actions-Semi Ats2819S Firmware: all versions
Actions-Semi Ats2819T Firmware: all versions

References

https://dl.packetstormsecurity.net/papers/general/braktooth.pdf
https://launchstudio.bluetooth.com/ListingDetails/76427
https://www.actions-semi.com/index.php?id=3581&siteId=4
https://dl.packetstormsecurity.net/papers/general/braktooth.pdf
https://launchstudio.bluetooth.com/ListingDetails/76427
https://www.actions-semi.com/index.php?id=3581&siteId=4

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