Cyber Resilience

CVE-2021-3455

MediumPublic PoC

Published: 19 October 2021

Published
19 October 2021
Modified
21 November 2024
KEV Added
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Patch
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CVSS Score v3.1 4.3 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS Score 0.0039 60.7th percentile
Risk Priority 9 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-3455 is a medium-severity Use After Free (CWE-416) vulnerability in Zephyrproject Zephyr. Its CVSS base score is 4.3 (Medium).

Operationally, ranked in the top 39.3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

Disconnecting L2CAP channel right after invalid ATT request leads freeze. Zephyr versions >= 2.4.0, >= 2.5.0 contain Use After Free (CWE-416). For more information, see https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-7g38-3x9v-v7vp

CWE(s)
CWE-416

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

zephyrproject
zephyr
2.4.0 — 2.6.0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SI-16 Memory Protection
addresses: CWE-416

Use-after-free exploits that achieve arbitrary code execution are blocked or significantly hardened by non-executable pages and ASLR.

References