How severe is CVE-2021-31611?

CVE-2021-31611 has a CVSS 3.x base score of 5.7, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-31611 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-31611?

CVE-2021-31611 primarily affects Zh-jieli Ac6901 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-2021-31611?

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

When was CVE-2021-31611 published?

CVE-2021-31611 was published on 2021-09-07 and last updated on 2026-06-17.

CVE-2021-31611

CVE-2021-31611 is a medium-severity vulnerability in Zh-jieli Ac6901 Firmware with a CVSS 3.x base score of 5.7. 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 5.7)
CVSS v2: 3.3
EPSS exploit prediction: 0% (29th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-667
Affected product: Zh-jieli Ac6901 Firmware
Published: 2021-09-07
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2021-31611?: 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.
How severe is CVE-2021-31611?: CVE-2021-31611 has a CVSS 3.x base score of 5.7, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-31611 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-31611?: CVE-2021-31611 primarily affects Zh-jieli Ac6901 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-2021-31611?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-31611 published?: CVE-2021-31611 was published on 2021-09-07 and last updated on 2026-06-17.

References

Affected products (5)

cpe:2.3:o:zh-jieli:ac6901_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:zh-jieli:ac6925_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:zh-jieli:ac6926_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:zh-jieli:ac6928_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:zh-jieli:ac6921_firmware:-:*:*:*:*:*:*:*

More vulnerabilities in Zh-jieli Ac6901 Firmware

CVE-2021-31612 — Medium (CVSS 6.5): The Bluetooth Classic implementation on Zhuhai Jieli AC690X devices does not properly handle the reception of an…
CVE-2021-31613 — Medium (CVSS 6.5): The Bluetooth Classic implementation on Zhuhai Jieli AC690X and AC692X devices does not properly handle the reception…

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