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Fencer Intel
high 7.8

CVE-2021-41379 kev+ ransomware in the critical feed json

Windows Installer Elevation of Privilege Vulnerability

published 4y ago modified 2mo ago also EUVD-2021-28407

cvss
7.8
version 3.1, CNA
cisa kev
Exploited
added 2022-03-03, used in ransomware
epss
19.5%
EPSS 19.5% chance of exploitation in 30 days, percentile 97%
public exploits
0
none known

Summary

Windows Installer Elevation of Privilege Vulnerability

Patch / fix

cisa required action Apply updates per vendor instructions.

  • Microsoft Windows 10 Version 1507 10.0.10240.19119
  • Microsoft Windows 10 Version 1607 10.0.14393.4770
  • Microsoft Windows 10 Version 1809 10.0.17763.2300
  • Microsoft Windows 10 Version 1909 10.0.18363.1916
  • Microsoft Windows 10 Version 2004 10.0.19041.1348
  • Microsoft Windows 10 Version 20H2 10.0.19042.1348
  • Microsoft Windows 10 Version 21H1 10.0.19043.1348
  • Microsoft Windows 11 version 21H2 10.0.22000.318
  • Microsoft Windows 7 6.1.7601.25769
  • Microsoft Windows 7 Service Pack 1 6.1.7601.25769
  • Microsoft Windows 8.1 6.3.9600.20174
  • Microsoft Windows Server 2008 R2 Service Pack 1 6.1.7601.25769
  • Microsoft Windows Server 2008 R2 Service Pack 1 (Server Core installation) 6.1.7601.25769
  • Microsoft Windows Server 2008 Service Pack 2 6.0.6003.21282
  • Microsoft Windows Server 2008 Service Pack 2 (Server Core installation) 6.0.6003.21282
  • Microsoft Windows Server 2012 6.2.9200.23517
  • Microsoft Windows Server 2012 (Server Core installation) 6.2.9200.23517
  • Microsoft Windows Server 2012 R2 6.3.9600.20174
  • Microsoft Windows Server 2012 R2 (Server Core installation) 6.3.9600.20174
  • Microsoft Windows Server 2016 10.0.14393.4770
  • Microsoft Windows Server 2016 (Server Core installation) 10.0.14393.4770
  • Microsoft Windows Server 2019 10.0.17763.2300
  • Microsoft Windows Server 2019 (Server Core installation) 10.0.17763.2300
  • Microsoft Windows Server 2022 10.0.20348.350
  • Microsoft Windows Server version 2004 10.0.19041.1348
  • Microsoft Windows Server version 20H2 10.0.19042.1348

Is CVE-2021-41379 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Timeline

  1. Published
  2. Added to CISA KEV
  3. CISA patch deadline
  4. CISA SSVC: exploitation active

Known exploited

Added
4y ago
Patch by
2022-03-17 (4y ago)
Ransomware
Known to be used in ransomware campaigns
Required action
Apply updates per vendor instructions.
Vendor, product
Microsoft, Windows
CISA name
Microsoft Windows Installer Privilege Escalation Vulnerability

ATT&CK techniques

How it is exploited and what it leads to, in MITRE ATT&CK terms.

  • T1078 Valid Accounts exploitation
  • T1068 Exploitation for Privilege Escalation primary impact

kev release 2025-07-28, att&ck v16.1. KEV to ATT&CK mappings by the MITRE Center for Threat-Informed Defense (Mappings Explorer, Apache-2.0). © 2026 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation. Terms of use

CISA SSVC

Exploitation
Active, exploited in the wild
Automatable
no
Technical impact
total
Assessed
last yr.

Exploit prediction

19.45% chance of exploitation in the next 30 days, higher than 97% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C
CNA 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 4.6 AV:L/AC:L/Au:N/C:P/I:P/A:P

Affected products

  • Microsoft Windows 10 Version 1507
  • Microsoft Windows 10 Version 1607
  • Microsoft Windows 10 Version 1809
  • Microsoft Windows 10 Version 1909
  • Microsoft Windows 10 Version 2004
  • Microsoft Windows 10 Version 20H2
  • Microsoft Windows 10 Version 21H1
  • Microsoft Windows 11 version 21H2
  • Microsoft Windows 7
  • Microsoft Windows 7 Service Pack 1
  • Microsoft Windows 8.1
  • Microsoft Windows Server 2008 R2 Service Pack 1
  • Microsoft Windows Server 2008 R2 Service Pack 1 (Server Core installation)
  • Microsoft Windows Server 2008 Service Pack 2
  • Microsoft Windows Server 2008 Service Pack 2 (Server Core installation)
  • Microsoft Windows Server 2012
  • Microsoft Windows Server 2012 (Server Core installation)
  • Microsoft Windows Server 2012 R2
  • Microsoft Windows Server 2012 R2 (Server Core installation)
  • Microsoft Windows Server 2016
  • Microsoft Windows Server 2016 (Server Core installation)
  • Microsoft Windows Server 2019
  • Microsoft Windows Server 2019 (Server Core installation)
  • Microsoft Windows Server 2022
  • Microsoft Windows Server version 2004
  • Microsoft Windows Server version 20H2

Classification

Weakness
  • CWE-59 Improper Link Resolution Before File Access

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.