vciy

CVE-2021-38632

INDEX BUILT · 2026-09-20

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Windows BitLocker Security Feature Bypass Vulnerability

CVE-2021-386324 of 4 sources documented this
12

rank 12 = 0 + 5 + 0 + 7 + 0

rank@v1 · backlog

Someone is already using it

CISA KEV catalog · public proof-of-concept · FIRST EPSS

EPSS 0.00822  ·  without this subject the record ranks 12

What it costs you if it fires

NVD CVSS base score, then the CNA's own

CVSS 2.1, from NVD  ·  without this subject the record ranks 7

It is getting worse, not staying still

FIRST EPSS series, rescorings and bad loads removed

no persisting rise in 365 days  ·  without this subject the record ranks 12

How much of the world it touches

NVD CPE configurations

8 products in the CPE ranges  ·  without this subject the record ranks 5

Someone else already set the date

CISA KEV remediation due date

no CISA due date  ·  without this subject the record ranks 12

Unaudited dollar value2 of 3 inputs carry a receipt
Exposure$36,200over the next 30 days, if this record is yours
Movement-$419,000on 2022-02-04, the last material move, 4 years, 6 months before this reading
Basisassumeda published average, not your estate

$36,200 = $4.99M incident cost x 0.8814887365328109 exposure x 0.00822 likelihood

udv@v1 · unaudited · wrong for you until you say what you run

$4.99M is the cost of a breach that happened, from IBM Cost of a Data Breach Report 2026, global average. It is not the value of any asset of yours. That average already covers breaches of every severity, so scaling it by exposure understates a partial-impact record. That is an assumption, not a measurement. Your own asset value goes in the decision record.

Hindsight · the state

0.00822EPSSNOT IN KEVas of 2026-09-20
Severity5.7 MEDIUMreceipt
Harmpartial impactreceipt
Exploitationnone in held sources
Defensefix version namedreceipt
Movementrisenreceipt
PLATEAU10Minimal movement since 2022-02-04, 1649 days at 0.01, as of 2026-08-11. arc-rules@v1

Foresight · where to check next

No weakness class or product neighbourhood is held for this record, so this index cannot name anywhere to check next. That is an absence in the record, not a finding about the software.

Color is a claim, not decoration:the hostile worldthe defenseno signal

Sources disagree here.

Severity score
Microsoft5.7 MEDIUMreceipt
NVD2.1 LOWreceipt
Scoring standard
MicrosoftCVSS v3.1receipt
NVDCVSS v2.0receipt

Both shown, dated. We don't pick winners. disagreement-rules@v1

Running Microsoft Windows 10 Version 1607? Check your version

A deterministic range check against the ranges this record publishes. It tells you where a version sits in the record, not whether your deployment is exploitable. No account needed.

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Harm, if it fires from the vector and the weakness

Written for the ticket you're about to file.

Reachneeds physical access · no privileges required · no user interaction · high attack complexityreceipt
ImpactComplete confidentiality and integrity lossreceipt
Scored fromCVSS v3.1 · the CNA's vectorreceipt
Weakness classNo CWE mapping in held sources.

CISA KEV & Federal Remediation Deadline from the record and CISA

The fix, and how long it's been waiting.

Fixed in10.0.14393.4651; 10.0.17763.2183; 10.0.18363.1801; 10.0.19041.1237; 10.0.19042.1237; 10.0.19043.1237; 10.0.20348.230receipt
Patch available sinceNo dated patch-availability record in held sources. The index holds reference URLs without dates and only the current revision of the CVE record, so the day a fix first existed cannot be derived. Only the versions it landed in.

Exploit Status & Known PoCs a ladder, not a score

Current rung: Nothing observed in held sources.

  • RUNG 1Nothing observed in held sources
  • RUNG 2Proof-of-concept published
  • RUNG 3Exploited in the wild · CISA KEV listed
  • RUNG 4Ransomware campaign use known

Authority who says so

CVSS, the CNA5.7 MEDIUMreceipt
CVSS, NVD2.1 LOWreceipt
Exploit probability0.00822 · top 44% of all CVEsreceipt
Blast breadth2 products across 1 vendorderived
Assigned bymicrosoftreceipt
Recorded changes26 · last 19 Sep 2026derived

Affected & Fixed Versions as published

Affected productMicrosoft Windows 10 Version 1607; Microsoft Windows 10 Version 1809; Microsoft Windows 10 Version 1909; Microsoft Windows 10 Version 2004; Microsoft Windows 10 Version 20H2…receipt
Published rangesmicrosoft windows 10 20h2; microsoft windows 10 21h1; microsoft windows 10 1607; microsoft windows 10 1809receipt
Show all 8 published ranges
microsoft windows 10 20h2
microsoft windows 10 21h1
microsoft windows 10 1607
microsoft windows 10 1809
microsoft windows 10 1909
microsoft windows 10 2004
microsoft windows server 2016 20h2
microsoft windows server 2016 2004
Fixed in10.0.14393.4651; 10.0.17763.2183; 10.0.18363.1801; 10.0.19041.1237; 10.0.19042.1237; 10.0.19043.1237; 10.0.20348.230receipt

A rung lights from a row in the index, never from an assessment. "Held sources" is the true scope of the claim: this index reads the CVE record, NVD, CISA KEV, FIRST's EPSS and public proof-of-concept repositories, and it does not observe attacks.

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What it is stated by the CNA

Windows BitLocker Security Feature Bypass Vulnerability receipt

NVD's analysis a second authority

severity
2.1 AV:L/AC:L/Au:N/C:P/I:N/A:N
affected versions
microsoft windows 10 20h2; microsoft windows 10 21h1; microsoft windows 10 1607; and 5 more, listed in full below
also scored by
[email protected] 5.7 CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N · [email protected] 4.6 CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

The CNA scored it 5.7 and NVD 2.1. Both are shown because both were published; we do not pick one.

check it yourself msrc.microsoft.com receipt

Dated events

2022-01-06EPSS moved 0.05 to 0.182022-02-04EPSS moved 0.18 to 0.082022-04-01EPSS moved 0.08 to 0.02

Movement the material steps

16 Sep 20210.00416
6 Jan 20220.17642 · crossed 0.10
4 Feb 20220.08127 · crossed 0.10
7 Mar 20235.4e-4 · scoring model v2023.03.01
17 Mar 20250.00325 · scoring model v2025.03.14
15 Jun 20260.00646 · scoring model v2026.06.15
11 Aug 20260.00822
Show all 26 observations
16 Sep 20210.00416
28 Sep 20210.04557
6 Jan 20220.17642
4 Feb 20220.08127
1 Apr 20220.02251
4 Dec 20220.02427
7 Mar 20235.4e-4
8 Mar 20230.00054
29 Dec 20230.00055
21 Apr 20240.00054
18 May 20240.00069
31 May 20240.00079
21 Aug 20240.00074
17 Dec 20240.00043
17 Mar 20250.00325
19 Mar 20250.00336
25 Mar 20250.00449
29 Mar 20250.01855
30 Mar 20250.00449
7 Jul 20250.00475
17 Nov 20250.00428
18 Nov 20250.00331
21 Nov 20250.00428
15 Jun 20260.00646
9 Jul 20260.00662
11 Aug 20260.00822

26 observations held. A highlighted step crossed a promotion threshold. A step marked with a scoring model moved because the instrument was replaced, not because the vulnerability changed. receipt

The full biography

EPSS 0.00822Published2021-09-15Index as of2026-08-11

The record had been public for 4 years, 10 months when this index was last written.

Published 2021-09-15 receipt · Index as of 2026-08-11 derived

Siblings and hubs

Records related to this one

Its defect family

microsoft windows

Of the 24 records in this family, this is the only one holding a stated fix version: 10.0.14393.4651; 10.0.17763.2183; 10.0.18363.1801; 10.0.1904.

Grouped by shared product and weakness, not by shared vulnerability. Each record's own state is on its own page.

Family membership: computed, pro@dim2000

This record is one of a group, and the group's page describes all of them. This page is kept and dated, and the defect family's own page is the one we offer for indexing: the whole group.

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What usually comes next

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