What is CVE-2021-40456?

CVE-2021-40456 is a security advisory published by Microsoft with High severity. EchelonGraph links Microsoft's advisory rather than copying its page; it is at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-40456.

Which CVE IDs does CVE-2021-40456 cover?

CVE-2021-40456 covers the following CVE IDs: CVE-2021-40456. Each CVE has its own detail page on EchelonGraph Pulse with its EchelonGraph score.

What is the CVSS v3 score of CVE-2021-40456?

CVE-2021-40456 has a CVSS v3 base score of 5.3, published by Microsoft Security Response Center (MSRC).

Which products are affected by CVE-2021-40456?

CVE-2021-40456 affects 6 products, including: Windows Server 2019; Windows Server 2019 (Server Core installation); Windows Server 2022; Windows Server 2022 (Server Core installation); Windows Server, version 2004 (Server Core installation); and others — see the full list on the advisory page.

How do I remediate CVE-2021-40456?

Microsoft lists 3 KB articles for CVE-2021-40456: KB5006672, KB5006699, KB5006670. Each is listed on this page with its fixed build; Microsoft's advisory is at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-40456.

CVE-2021-40456HighMicrosoft CVSS 5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C

Microsoft security update for CVE-2021-40456 — Windows

Vendor

Microsoft Security Response Center (MSRC)

Published

October 12, 2021

Last Modified

—

🔗 CVE IDs covered (1)

CVE-2021-40456 →

📋 Microsoft's advisory

EchelonGraph does not copy Microsoft's advisory page: its FAQ and remediation text are not shown here. Read the advisory on https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-40456. This page also shows what EchelonGraph holds for CVE-2021-40456, with the description from its CVE record, which the CVE Numbering Authority that assigned the CVE wrote: for a CVE Microsoft assigned, often in the words of Microsoft's own advisory.

🎯 Affected products6

Windows Server 2019
Windows Server 2019 (Server Core installation)
Windows Server 2022
Windows Server 2022 (Server Core installation)
Windows Server, version 2004 (Server Core installation)
Windows Server, version 20H2 (Server Core Installation)

✅ Updates Microsoft lists: 3 KB articles

4 rows: one per KB article or update, update type and fixed build. Their details are on Microsoft's advisory.

KB article	Update	Fixed build
KB5006672	Security Update	10.0.17763.2237
KB5006699	Security Update	10.0.20348.288
KB5006670	Security Update	10.0.19041.1288
KB5006670	Security Update	10.0.19042.1288

🧭 EchelonGraph on CVE-2021-40456

EchelonGraph score: 7.5 HIGH
CISA KEV: Not listed
Fix status: A fix is available — apply it.

Description from the CVE record (CVE.org), as published by its numbering authority

Windows AD FS Security Feature Bypass Vulnerability

Published by Microsoft Corporation, the CVE Numbering Authority that assigned CVE-2021-40456, in its CVE record at CVE.org; reused under the CVE Program's Terms of Use (its licence and MITRE's copyright notice are in our Terms of Service).

🔗 CVE IDs covered (1)

📋 Microsoft's advisory

🎯 Affected products6

✅ Updates Microsoft lists: 3 KB articles

🧭 EchelonGraph on CVE-2021-40456

🔗 References (6)