CVE-2021-3454

Truncated L2CAP K-frame causes assertion failure

4.3 Medium

Truncated L2CAP K-frame causes assertion failure. Zephyr versions >= 2.4.0, >= v.2.50 contain Improper Handling of Length Parameter Inconsistency (CWE-130), Reachable Assertion (CWE-617). For more information, see https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-fx88-6c29-vrp3

Attack profile

How easy it is to exploit

Attack vector: Adjacent network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: Low

Exploit likelihood

0.96%Up 0.5 points since Oct 20, 2021

What each source reports

CVE List Score used 4.3

Truncated L2CAP K-frame causes assertion failure

Record: CVE-2021-3454
CVSS 3.1: 4.3 MediumCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weakness: CWE-130, CWE-617
Updated: 2026-11-02

EUVDEUVD-2021-26777 4.3

Record: EUVD-2021-26777
CVSS 3.1: 4.3 MediumCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Updated: 2026-11-03

NVD 4.3

Record: CVE-2021-3454
CVSS 3.1: 4.3 MediumCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0: 5.0 MediumAV:N/AC:L/Au:N/C:N/I:N/A:P
Weakness: CWE-130, CWE-617
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-2021-3454 is a medium vulnerability (CVSS 4.3) in Zephyrproject Zephyr, published October 19, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.96%, the 61st percentile. No source names a fixed version.

References

github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-fx88-6c29-vrp3