Vulnerability report

Trusted Third Party Report Confirmed Confidence In CISA KEV

CVE-2021-1675

Windows Print Spooler Remote Code Execution Vulnerability

Microsoft / Windows 10 Version 1809 · affected before 10.0.17763.1999

Watch CVE-2021-1675 Browse KEV feed
Severity
CVSS 7.8 · High
Confidence
Confirmed
Exploit status
Trusted Third Party Report
EPSS
85.3%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2021-1675 is an unauthenticated Windows Print Spooler Remote Code Execution Vulnerability affecting Microsoft Windows 10 Version 1809 and 24 other products.

Have exploitation attempts been observed?

Yes. Exploitation attempts have been reported for this vulnerability. Previdian lists it as a known exploited vulnerability. Listed in CISA KEV. Also reported by third-party sources. Confidence is confirmed.

Who is affected?

Affected products include Microsoft / Windows 10 Version 1809 and 24 other products, including affected before 10.0.17763.1999, affected before 10.0.18363.1621, and affected before 10.0.19043.1052.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

Windows Print Spooler Remote Code Execution Vulnerability

Windows Print Spooler Remote Code Execution Vulnerability

Microsoft Affected
Windows 10 Version 1809
Before 10.0.17763.1999
Microsoft Affected
Windows Server 2019
Before 10.0.17763.1999
Microsoft Affected
Windows Server 2019 (Server Core installation)
Before 10.0.17763.1999
Microsoft Affected
Windows 10 Version 1909
Before 10.0.18363.1621
Microsoft Affected
Windows 10 Version 21H1
Before 10.0.19043.1052
Microsoft Affected
Windows 10 Version 2004
Before 10.0.19041.1052
Microsoft Affected
Windows Server version 2004
Before 10.0.19041.1052
Microsoft Affected
Windows 10 Version 20H2
Before 10.0.19042.1052
Microsoft Affected
Windows Server version 20H2
Before 10.0.19042.1052
Microsoft Affected
Windows 10 Version 1507
Before 10.0.10240.18967
Microsoft Affected
Windows 10 Version 1607
Before 10.0.14393.4467
Microsoft Affected
Windows Server 2016
Before 10.0.14393.4467
Microsoft Affected
Windows Server 2016 (Server Core installation)
Before 10.0.14393.4467
Microsoft Affected
Windows 7
Before 6.1.7601.25632
Microsoft Affected
Windows 7 Service Pack 1
Before 6.1.7601.25632
Microsoft Affected
Windows 8.1
Before 6.3.9600.20045 Before 6.3.9600.20044
Microsoft Affected
Windows Server 2008 Service Pack 2
Before 6.0.6003.21137
Microsoft Affected
Windows Server 2008 Service Pack 2 (Server Core installation)
Before 6.0.6003.21137
Microsoft Affected
Windows Server 2008 Service Pack 2
Before 6.0.6003.21137
Microsoft Affected
Windows Server 2008 R2 Service Pack 1
Before 6.1.7601.25632
Microsoft Affected
Windows Server 2008 R2 Service Pack 1 (Server Core installation)
Before 6.1.7601.25632
Microsoft Affected
Windows Server 2012
Before 6.2.9200.23372
Microsoft Affected
Windows Server 2012 (Server Core installation)
Before 6.2.9200.23372
Microsoft Affected
Windows Server 2012 R2
Before 6.3.9600.20045 Before 6.3.9600.20044
Microsoft Affected
Windows Server 2012 R2 (Server Core installation)
Before 6.3.9600.20045 Before 6.3.9600.20044
View vendor advisory (opens in new tab)
Published
08 Jun 2021
Exploitation Attempts Reported
03 Nov 2021
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required

Tags

microsoft cisa malware windows ransomware metasploit metasploit_scanner

CVE References

Exploitation evidence

Evidence of exploitation attempts

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploitation Attempts Observed in the Wild

CISA

Recorded 03 Nov 2021

A trusted third party reported exploitation attempts.

Targeted by Malware-Related Exploitation Attempts

CISA

Recorded 03 Nov 2021

Exploitation attempts against this vulnerability are associated with malware-related payloads.

Proof of concept available

GitHub

Recorded 29 Jun 2021

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
CISA First 2021-11-03 00:00 UTC
CVE 2026-08-12 04:21 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Metasploit https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/windows/dcerpc/cve_2021_1675_printnightmare.rb 28 Apr 2025

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

7.8 High

Potential damage if exploited. Separate from whether attackers are using it.

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS

85.3%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Recent mention · SOCRadar

INC and The Gentlemen Ransomware: Exposed AI Infrastructure

SOCRadar Threat Research Unit (STRU) has uncovered an AI-driven intrusion ecosystem run by affiliates of the INC Ransomware and The Gentlemen Ransomware groups. A single publicly accessible command-and-control server exposed the operators’ AI session databases, their central...

Read full advisory

All CVSS Scores

CVSS v3.1 7.8 High

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS v2.0 9.3 High

AV:N/AC:M/Au:N/C:C/I:C/A:C

All Mentions

Recent mention · SOCRadar

INC and The Gentlemen Ransomware: Exposed AI Infrastructure

SOCRadar · 20 Oct 2026

SOCRadar Threat Research Unit (STRU) has uncovered an AI-driven intrusion ecosystem run by affiliates of the INC Ransomware and The Gentlemen Ransomware groups. A single publicly accessible command-and-control server exposed the operators’ AI session databases, their central knowledge base and the source code of Phantom, a new “Autonomous Red Team Kill Chain Framework”. Configuration files, […]

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

mstxq17/CVE-2021-1675_RDL_LPE

github · Created 2021-09-01 11:25:04 UTC · 148 stars · AI assessment 90%

PrintNightMare LPE提权漏洞的CS 反射加载插件。开箱即用、通过内存加载、混淆加载的驱动名称来ByPass Defender/EDR。

calebstewart/CVE-2021-1675

github · Created 2021-07-01 23:45:58 UTC · 1050 stars · AI assessment 90%

Pure PowerShell implementation of CVE-2021-1675 Print Spooler Local Privilege Escalation (PrintNightmare)

hlldz/CVE-2021-1675-LPE

github · Created 2021-07-01 09:47:13 UTC · 333 stars · AI assessment 90%

Local Privilege Escalation Edition for CVE-2021-1675/CVE-2021-34527

evilashz/CVE-2021-1675-LPE-EXP

github · Created 2021-07-01 09:00:31 UTC · 59 stars · AI assessment 90%

PrintNightmare , Local Privilege Escalation of CVE-2021-1675 or CVE-2021-34527

cube0x0/CVE-2021-1675

github · Created 2021-06-29 17:24:14 UTC · 1881 stars · AI assessment 90%

C# and Impacket implementation of PrintNightmare CVE-2021-1675/CVE-2021-34527

Timeline

From disclosure to observed exploitation attempts

  1. 04:21 UTC

    KEV confirmed by CVE

    Exploitation attempts reported by an external source

  2. 15:02 UTC

    Metasploit module available

    Exploit module available

  3. 00:00 UTC

    Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  4. 00:00 UTC

    Targeted by malware-related exploitation attempts

    Malware-related exploitation attempts or payloads reported

  5. 17:24 UTC

    Public PoC available

    Public proof-of-concept code published

  6. 22:46 UTC

    CVE published

    Vulnerability disclosed publicly

  7. 00:00 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

Start 14-day Pro trial Read API docs
  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2021-1675

Sample API response 
{
  "cve_id": "CVE-2021-1675",
  "confidence": "Confirmed",
  "cvss_score": 7.8,
  "cvss_estimated": false,
  "epss_score": 0.85305,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}