How severe is CVE-2021-31785?

CVE-2021-31785 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-31785 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-31785?

CVE-2021-31785 primarily affects Actions-semi Ats2819p Firmware. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-31785?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-31785 published?

CVE-2021-31785 was published on 2021-09-07 and last updated on 2026-06-17.

CVE-2021-31785

CVE-2021-31785 is a medium-severity vulnerability in Actions-semi Ats2819p Firmware with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-667.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 6.1
EPSS exploit prediction: 0% (36th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-667
Affected product: Actions-semi Ats2819p Firmware
Published: 2021-09-07
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2021-31785?: 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.
How severe is CVE-2021-31785?: CVE-2021-31785 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-31785 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-31785?: CVE-2021-31785 primarily affects Actions-semi Ats2819p Firmware. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-31785?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-31785 published?: CVE-2021-31785 was published on 2021-09-07 and last updated on 2026-06-17.

References

Affected products (5)

cpe:2.3:o:actions-semi:ats2819p_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:actions-semi:ats2815_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:actions-semi:ats2819_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:actions-semi:ats2819s_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:actions-semi:ats2819t_firmware:-:*:*:*:*:*:*:*

More vulnerabilities in Actions-semi Ats2819p Firmware

CVE-2021-31787 — Medium (CVSS 6.5): The Bluetooth Classic implementation on Actions ATS2815 chipsets does not properly handle the reception of continuous…
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