vciy

CVE-2021-28312

INDEX BUILT · 2026-09-20

No source can show you its own past. This one can.

Print this page to keep the view as it stands on this date. Everything hidden behind a disclosure opens, and every receipt prints with its value.

Windows NTFS Denial of Service Vulnerability

CVE-2021-283124 of 4 sources documented this
33

rank 33 = 16 + 11 + 0 + 6 + 0

rank@v1 · scheduled

Someone is already using it

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

EPSS 0.06599  ·  without this subject the record ranks 17

What it costs you if it fires

NVD CVSS base score, then the CNA's own

CVSS 4.3, from NVD  ·  without this subject the record ranks 22

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 33

How much of the world it touches

NVD CPE configurations

6 products in the CPE ranges  ·  without this subject the record ranks 27

Someone else already set the date

CISA KEV remediation due date

no CISA due date  ·  without this subject the record ranks 33

Unaudited dollar value2 of 3 inputs carry a receipt
Exposure$79,200over the next 30 days, if this record is yours
Movement-$172,000on 2025-11-21, the last material move, 6 months before this reading
Basisassumeda published average, not your estate

$79,200 = $4.99M incident cost x 0.24048551839932833 exposure x 0.06599 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

0.06599EPSSNOT IN KEVas of 2026-09-20
Severity3.3 LOWreceipt
Harmpartial impactreceipt
Exploitationpublic proof-of-conceptreceipt
Defenseno fix version held
Movementscoring model changedreceipt
PLATEAU10Minimal movement since 2025-11-21, 206 days at 0.07, as of 2026-06-15. 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
Microsoft3.3 LOWreceipt
NVD4.3 MEDIUMreceipt
Scoring standard
MicrosoftCVSS v3.1receipt
NVDCVSS v2.0receipt

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

Running Microsoft Windows 10 Version 1809? 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.

Watch this record

Matches your own product list against every record this index holds, and tells you when one of them moves.

What counts as a move

Set up a watchlist (needs a Practitioner account)

Record your call

Keep your verdict, your reason and the evidence together. The record takes its date when you save it.

AcceptDeferPatch by…Not affectedMitigated

Choose your verdict, then sign in or use an email link. Your first 100 records are free. Evidence is frozen when the record is created.

Private to your organization unless you share it. Put the proof link in your ticket so a reviewer can inspect the basis for your call. See how decision records work.

Harm, if it fires from the vector and the weakness

Written for the ticket you're about to file.

Reachneeds local access · no privileges required · user interaction required · low attack complexityreceipt
ImpactPartial availability 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 inNo fix version in held sources, as the index stood on 15 Jun 2026.
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: Proof-of-concept published · 1 public repository, 2021-05-07.

  • RUNG 1Nothing observed in held sources
  • RUNG 2Proof-of-concept published · 1 public repository2021-05-07receipt
  • RUNG 3Exploited in the wild · CISA KEV listed
  • RUNG 4Ransomware campaign use known

Authority who says so

CVSS, the CNA3.3 LOWreceipt
CVSS, NVD4.3 MEDIUMreceipt
Exploit probability0.06599 · top 6% of all CVEsreceipt
Blast breadth2 products across 1 vendorderived
Assigned bymicrosoftreceipt
Recorded changes39 · last 19 Sep 2026derived

Affected & Fixed Versions as published

Affected productMicrosoft Windows 10 Version 1809; Microsoft Windows Server 2019; Microsoft Windows Server 2019 (Server Core installation); Microsoft Windows 10 Version 1909…receipt
Published rangesmicrosoft windows 10 20h2; microsoft windows 10 1909; microsoft windows 10 2004; microsoft windows server 2016 20h2receipt
Show all 6 published ranges
microsoft windows 10 20h2
microsoft windows 10 1909
microsoft windows 10 2004
microsoft windows server 2016 20h2
microsoft windows server 2016 1909
microsoft windows server 2016 2004

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.

Did this affect your environment?Answering needs an account.

What it is stated by the CNA

Windows NTFS Denial of Service Vulnerability receipt

NVD's analysis a second authority

severity
4.3 AV:N/AC:M/Au:N/C:N/I:N/A:P
affected versions
microsoft windows 10 20h2; microsoft windows 10 1909; microsoft windows 10 2004; and 3 more, listed in full below
also scored by
[email protected] 3.3 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L · [email protected] 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

The CNA scored it 3.3 and NVD 4.3. Both are shown because both were published; we do not pick one.

check it yourself portal.msrc.microsoft.com receipt

Dated events

2021-04-17EPSS moved 0.01 to 0.062022-01-06EPSS moved 0.06 to 0.212025-11-21EPSS moved 0.23 to 0.08

Movement the material steps

14 Apr 20210.00518
6 Jan 20220.21078 · crossed 0.10
4 Feb 20220.09127 · crossed 0.10
7 Mar 20230.002 · scoring model v2023.03.01
17 Mar 20250.09708 · scoring model v2025.03.14
19 Mar 20250.23472 · crossed 0.10
20 Mar 20250.09444 · crossed 0.10
27 Mar 20250.23472 · crossed 0.10
28 Mar 20250.09444 · crossed 0.10
29 Mar 20250.23472 · crossed 0.10
30 Mar 20250.09444 · crossed 0.10
18 Nov 20250.22572 · crossed 0.10
21 Nov 20250.08276 · crossed 0.10
15 Jun 20260.06599 · scoring model v2026.06.15

This score more than doubled inside 72 hours. Both observations are in the full history below.

Show all 36 observations
14 Apr 20210.00518
17 Apr 20210.05618
6 Jan 20220.21078
4 Feb 20220.09127
1 Apr 20220.02251
2 Jul 20220.02427
30 Oct 20220.02632
7 Mar 20230.002
8 Mar 20230.00200
27 Apr 20230.00149
24 May 20230.00182
6 Jul 20230.00124
23 Oct 20230.00169
18 Nov 20230.00179
15 Dec 20230.00195
28 Dec 20230.00168
30 Dec 20230.00089
5 Mar 20240.00093
19 Mar 20240.00104
16 Apr 20240.00090
30 Apr 20240.00127
16 Aug 20240.00103
16 Sep 20240.00121
8 Nov 20240.00146
17 Dec 20240.00258
17 Mar 20250.09708
19 Mar 20250.23472
20 Mar 20250.09444
27 Mar 20250.23472
28 Mar 20250.09444
29 Mar 20250.23472
30 Mar 20250.09444
14 Jul 20250.08276
18 Nov 20250.22572
21 Nov 20250.08276
15 Jun 20260.06599

36 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 0.06599Published2021-04-13Public PoC2021-05-07Index as of2026-06-15

Exploit probability more than doubled between 2021-04-14 and 2021-04-17 (0.00518 → 0.05618) and the record had been public for 5 years, 2 months when this index was last written.

Published 2021-04-13 receipt · Public PoC 2021-05-07 receipt · Index as of 2026-06-15 derived

Siblings and hubs

Records related to this one

Browse the index from here

These are index-wide views, not findings about CVE-2021-28312.

What usually comes next

Everything above needs no account. What is below is work: assembling it, scoping it to your estate, watching it, and handing it to someone else.

Everything on this page is free. Public data. Withholding it protects nothing.