CVE-2021-3454: Truncated L2CAP K-frame causes assertion failure

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-10-19 · updated 2026-06-17
Weakness: CWE-130

Description

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

Affected products

zephyrproject zephyr: from 2.4.0 before 2.6.0 — fixed in 2.6.0

How to fix

Upgrade to a fixed version: zephyrproject zephyr 2.6.0. Check the vendor advisory for mitigations.

References

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

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