Windows Print Spooler Remote Code Execution Vulnerability

cisa required action Apply updates per vendor instructions.

1. 2021-06-08 First public exploit (Metasploit exploit/windows/dcerpc/cve_2021_1675_printnightmare)
2. 2021-06-08 Published
3. 2021-06-29 CISA SSVC: exploitation active
4. 2021-11-03 Added to CISA KEV
5. 2021-11-17 CISA patch deadline

Added

5 y ago (2021-11-03)

Patch by

2021-11-17 (4 y ago)

Ransomware

Known to be used in ransomware campaigns

Required action

Apply updates per vendor instructions.

Vendor, product

Microsoft, Windows

CISA name

Microsoft Windows Print Spooler Remote Code Execution Vulnerability

Groups reported to have exploited it in intrusions.

• Conti ransomware gang
• Vice Society ransomware gang
• Magniber ransomware gang
• BlackBasta ransomware gang

reported by blog.talosintelligence.comcrowdstrike.comcisa.govcisa.gov

Ransomware Vulnerability Matrix by BushidoUK (github.com/BushidoUK/Ransomware-Vulnerability-Matrix), reformatted per CVE. CC BY 4.0

Exploitation

Active, exploited in the wild

Automatable

no

Technical impact

total

Assessed

5 y ago (2021-06-29)

85.30% chance of exploitation in the next 30 days, higher than 99.7% of all scored CVEs (FIRST EPSS, 2026-11-08).

• Metasploit exploit/windows/dcerpc/cve_2021_1675_printnightmare Print Spooler Remote DLL Injection metasploit exploit, normal rank, 2021-06-08
• packetstormsecurity.com http://packetstormsecurity.com/files/167261/Print-Spooler-Remote-DLL-Injection.html referenced PoC, tagged "exploit" by a source, unverified

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

• portal.msrc.microsoft.com /en-US/security-guidance/advisory/CVE-2021-1675

  patch, vendor-advisory

• packetstormsecurity.com /files/167261/Print-Spooler-Remote-DLL-Injection.html

  exploit, third-party-advisory, vdb-entry

• kb.cert.org /vuls/id/383432

  third-party-advisory, us-government-resource

• packetstormsecurity.com /files/163349/Microsoft-PrintNightmare-Proof-Of-Concept.html

  third-party-advisory, vdb-entry

• packetstormsecurity.com /files/163351/PrintNightmare-Windows-Spooler-Service-Remote-Code-Execution.html

  third-party-advisory, vdb-entry

• cisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-1675

  government-resource, us-government-resource

• CVE List CVE-2021-1675
• NVD CVE-2021-1675

Fencer Vulns 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.