CVE-2021-41379Known exploitationPublic exploit

SYSTEM code execution via crafted junction deletion

Published Nov 10, 2021 · Updated Aug 19, 2026

Windows Installer in affected Microsoft Windows releases allows local users to escalate privileges by abusing a crafted junction. The Windows Installer service follows an attacker-created junction while deleting a file or directory, redirecting the privileged operation to an unintended target. Low-privileged code execution on the host is required; successful exploitation enables arbitrary code execution as SYSTEM.

CVSS severity5.5
Medium
EPSS probability19.53%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Windows Installer in affected Microsoft Windows releases allows local users to escalate privileges by abusing a crafted junction. The Windows Installer service follows an attacker-created junction while deleting a file or directory, redirecting the privileged operation to an unintended target. Low-privileged code execution on the host is required; successful exploitation enables arbitrary code execution as SYSTEM.

The record

CVE
CVE-2021-41379
Published
Nov 10, 2021
Updated
Aug 19, 2026
Vendor
Microsoft
Product
Windows 10 Version 1507
Classifications
CWE-59, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 10, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.0.10240.0 <10.0.10240.19119

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Microsoft · Windows 10 Version 1507version=10.0.10240.0 <10.0.10240.19119
Microsoft · Windows Server 2019version=10.0.17763.0 <10.0.17763.2300
Microsoft · Windows 7version=6.1.0 <6.1.7601.25769
Microsoft · Windows 10 Version 21H1version=10.0.0 <10.0.19043.1348
Microsoft · Windows 10 Version 1909version=10.0.0 <10.0.18363.1916
Microsoft · Windows 8.1version=6.3.0 <6.3.9600.20174
Microsoft · Windows Server 2016 (Server Core installation)version=10.0.14393.0 <10.0.14393.4770
Microsoft · Windows 11 version 21H2version=10.0.22000.0 <10.0.22000.318
Microsoft · Windows Server 2012 (Server Core installation)version=6.2.9200.0 <6.2.9200.23517
Microsoft · Windows Server 2012version=6.2.9200.0 <6.2.9200.23517
Microsoft · Windows Server, version 2004version=10.0.0 <10.0.19041.1348
Microsoft · Windows Server 2016version=10.0.14393.0 <10.0.14393.4770
Microsoft · Windows Server 2008 R2 Service Pack 1version=6.1.7601.0 <6.1.7601.25769
Microsoft · Windows 10 Version 20H2version=10.0.0 <10.0.19042.1348
Microsoft · Windows Server 2008 R2 Service Pack 1 (Server Core installation)version=6.1.7601.0 <6.1.7601.25769
Microsoft · Windows Server 2012 R2 (Server Core installation)version=6.3.9600.0 <6.3.9600.20174
Microsoft · Windows Server 2019 (Server Core installation)version=10.0.17763.0 <10.0.17763.2300
Microsoft · Windows 7 Service Pack 1version=6.1.0 <6.1.7601.25769
Microsoft · Windows Server version 20H2version=10.0.0 <10.0.19042.1348
Microsoft · Windows 10 Version 1607version=10.0.14393.0 <10.0.14393.4770
Microsoft · Windows Server 2008 Service Pack 2version=6.0.6003.0 <6.0.6003.21282
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.350
Microsoft · Windows 10 Version 2004version=10.0.0 <10.0.19041.1348
Microsoft · Windows 10 Version 1809version=10.0.0 <10.0.17763.2300; version=10.0.17763.0 <10.0.17763.2300
Microsoft · Windows Server 2012 R2version=6.3.9600.0 <6.3.9600.20174
Microsoft · Windows Server 2008 Service Pack 2 (Server Core installation)version=6.0.6003.0 <6.0.6003.21282

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
5.5Microsoft CorporationCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/A:P
7.8Zero Day InitiativeCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationReported
Public exploitPublished

Weakness, pattern, technique

CWE-59Improper Link Resolution Before File Access ('Link Following')
T1068Exploitation for Privilege Escalation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

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Your stack

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