How severe is CVE-2021-3861?

CVE-2021-3861 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over an adjacent network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability high.

Is CVE-2021-3861 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-3861?

CVE-2021-3861 affects Zephyrproject Zephyr. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-3861?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-3861 published?

CVE-2021-3861 was published on 2022-02-07 and last updated on 2026-06-17.

CVE-2021-3861

CVE-2021-3861 is a high-severity vulnerability in Zephyrproject Zephyr with a CVSS 3.x base score of 8.2. 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-787.

Key facts

Severity: High (CVSS 3.x base score 8.2)
CVSS v2: 7.2
EPSS exploit prediction: 0% (38th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Zephyrproject Zephyr
Published: 2022-02-07
Last modified: 2026-06-17

Description

The RNDIS USB device class includes a buffer overflow vulnerability. Zephyr versions >= v2.6.0 contain Heap-based Buffer Overflow (CWE-122). For more information, see https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-hvfp-w4h8-gxvj

Frequently asked questions

What is CVE-2021-3861?: The RNDIS USB device class includes a buffer overflow vulnerability. Zephyr versions >= v2.6.0 contain Heap-based Buffer Overflow (CWE-122). For more information, see https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-hvfp-w4h8-gxvj
How severe is CVE-2021-3861?: CVE-2021-3861 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over an adjacent network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability high.
Is CVE-2021-3861 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-3861?: CVE-2021-3861 affects Zephyrproject Zephyr. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-3861?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-3861 published?: CVE-2021-3861 was published on 2022-02-07 and last updated on 2026-06-17.

References

http://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-hvfp-w4h8-gxvj

Affected products (1)

cpe:2.3:o:zephyrproject:zephyr:*:*:*:*:*:*:*:*

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