Is CVE-2021-3581 actively exploited?

No active exploitation of CVE-2021-3581 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-3581 be exploited remotely?

Partially. CVE-2021-3581 requires adjacent network access (same network segment) to exploit.

What is the CVSS score of CVE-2021-3581?

CVE-2021-3581 has a CVSS score of 8.8 (HIGH).

HOME VULNERABILITIESCVE-2021-3581

HIGH

CVE-2021-3581

CWE-805Published: October 5, 2021· Updated: Jun 17, 2026

8.8

CVSS v3.1

Official Description

Buffer Access with Incorrect Length Value in zephyr. Zephyr versions >= >=2.5.0 contain Buffer Access with Incorrect Length Value (CWE-805). For more information, see https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-8q65-5gqf-fmw5

NVD Source

Technical Analysis

CVE-2021-3581 requires adjacent network access, limiting remote exploitation but still posing risk in shared or local network environments.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 8.8.