CVE-2021-34527Known exploitationPublic exploitNetwork attack vector

SYSTEM code execution via malicious printer driver load

Published Jul 2, 2021 · Updated Aug 10, 2026

Remote code execution in Microsoft Windows Print Spooler allows remote authenticated users to run arbitrary code with SYSTEM privileges. The spoolsv.exe service accepts a crafted MS-RPRN DCERPC driver-installation request and loads an attacker-controlled DLL as a privileged printer driver. A valid account and a reachable Print Spooler service are required, and insecure Point and Print policy values leave the host exposed.

CVSS severity8.8
High
EPSS probability99.79%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Remote code execution in Microsoft Windows Print Spooler allows remote authenticated users to run arbitrary code with SYSTEM privileges. The spoolsv.exe service accepts a crafted MS-RPRN DCERPC driver-installation request and loads an attacker-controlled DLL as a privileged printer driver. A valid account and a reachable Print Spooler service are required, and insecure Point and Print policy values leave the host exposed.

The record

CVE
CVE-2021-34527
Published
Jul 2, 2021
Updated
Aug 10, 2026
Vendor
Microsoft
Product
Windows 10 Version 1507
Classifications
T1210
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

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

Exploitability

Present is not the same as exploitable

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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 <10.0.10240.18969

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Microsoft · Windows 10 Version 1507version=10.0.10240.0 <10.0.10240.18969
Microsoft · Windows Server 2019version=10.0.17763.0 <10.0.17763.2029
Microsoft · Windows 8.1version=6.3.0 <6.3.9600.20046
Microsoft · Windows Server 2016 (Server Core installation)version=10.0.14393.0 <10.0.14393.4470
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 <6.2.9200.23383
Microsoft · Windows Server 2012version=6.2.9200.0 <6.2.9200.23383
Microsoft · Windows 10 Version 21H2version=10.0.19044.0 <10.0.19044.1415
Microsoft · Windows Server 2016version=10.0.14393.0 <10.0.14393.4470
Microsoft · Windows Server 2008 R2 Service Pack 1version=6.1.7601.0 <6.1.7601.25633
Microsoft · Windows 10 Version 20H2version=10.0.0 <10.0.19042.1083
Microsoft · Windows Server 2008 R2 Service Pack 1 (Server Core installation)version=6.1.7601.0 <6.1.7601.25633
Microsoft · Windows 10 Version 22H2version=10.0.19045.0 <10.0.19045.2251
Microsoft · Windows Server 2012 R2 (Server Core installation)version=6.3.9600.0 <6.3.9600.20046
Microsoft · Windows Server 2019 (Server Core installation)version=10.0.17763.0 <10.0.17763.2029
Microsoft · Windows 11, version 22H2version=10.0.22621.0 <10.0.22621.674
Microsoft · Windows Server version 20H2version=10.0.0 <10.0.19042.1083
Microsoft · Windows 10 Version 1607version=10.0.14393.0 <10.0.14393.4470
Microsoft · Windows Server 2008 Service Pack 2version=6.0.6003.0 <6.0.6003.21138
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.230
Microsoft · Windows 10 Version 1809version=10.0.0 <10.0.17763.2029; version=10.0.17763.0 <10.0.17763.2029
Microsoft · Windows Server 2012 R2version=6.3.9600.0 <6.3.9600.20046
Microsoft · Windows Server 2008 Service Pack 2 (Server Core installation)version=6.0.6003.0 <6.0.6003.21138

Published CVSS scores

9.0NVDAV:N/AC:L/Au:S/C:C/I:C/A:C
8.8NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
8.8MicrosoftCVSS:3.1/AV:N/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.

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No observations available

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

Weakness, pattern, technique

T1210Exploitation of Remote Services

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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