Cyber Resilience

CVE-2021-40818

Critical

Published: 08 September 2021

Published
08 September 2021
Modified
21 November 2024
KEV Added
—
Patch
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CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0046 64.3th percentile
Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-40818 is a critical-severity Classic Buffer Overflow (CWE-120) vulnerability in Glewlwyd Sso Server Project Glewlwyd Sso Server. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 35.7% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

scheme/webauthn.c in Glewlwyd SSO server through 2.5.3 has a buffer overflow during FIDO2 signature validation in webauthn registration.

CWE(s)
CWE-120

Related Threats

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

Affected Assets

glewlwyd sso server project
glewlwyd sso server
≤ 2.5.3

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.

SC-27 Platform-independent Applications
addresses: CWE-120

Platform-independent managed code eliminates the need for unchecked native buffer copies that are the root cause of classic buffer overflows.

References