CVE-2021-3581

Buffer Access with Incorrect Length Value in zephyr

7.0 High

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

Attack profile

How easy it is to exploit

Attack vector: Physical
Complexity: High
Privileges needed: None
User interaction: Required

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

0.35%Down 0.1 points since Oct 6, 2021

What each source reports

CVE List Score used 7.0

Buffer Access with Incorrect Length Value in zephyr

Record: CVE-2021-3581
CVSS 3.1: 7.0 HighCVSS:3.1/AV:P/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H
Weakness: CWE-805
Updated: 2026-11-02

EUVDEUVD-2021-26890 7.0

Record: EUVD-2021-26890
CVSS 3.1: 7.0 HighCVSS:3.1/AV:P/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H
Updated: 2026-11-03

NVD 7.0

Record: CVE-2021-3581
CVSS 3.1: 7.0 HighCVSS:3.1/AV:P/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H
CVSS 3.1: 8.8 HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 2.0: 5.8 MediumAV:A/AC:L/Au:N/C:P/I:P/A:P
Weakness: CWE-805, CWE-1284
Updated: 2026-11-02

Affected products

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases, published	EUVD
Nov 2, 2026	first indexed	CVE List, NVD

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-3581 is a high vulnerability (CVSS 7.0) in Zephyrproject Zephyr, published October 5, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.35%, the 28th percentile. No source names a fixed version.

References

github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-8q65-5gqf-fmw5