CVE-2021-1675: Microsoft Windows Print Spooler Remote Code Execution Vulnerability
Reference page built from the source records below, each shown as its source publishes it. Dataset version ref-3456e713e18e, updated 2026-11-02T23:39:54.475Z.
CISA Known Exploited Vulnerabilities
- Name
- Microsoft Windows Print Spooler Remote Code Execution Vulnerability
- Vendor
- Microsoft
- Product
- Windows
- Added to the catalog
- 2021-11-03
- Due date for US federal agencies
- 2021-11-17
- Weaknesses
- CWE-285
- Catalog version
- 2026.10.30
Microsoft Windows Print Spooler contains an unspecified vulnerability that allows for remote code execution.
Required action (CISA)
Apply updates per vendor instructions.
Ransomware use: CISA marks this vulnerability as known to be used in ransomware campaigns. CISA does not say which group used it.
Links in CISA's notes
Read on 2026-11-02T23:39:54.475Z under licence cisa-kev-cc0@b0067899 from https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json
NVD analysis
- Status
- Analyzed
- Published
- 2021-06-08T23:15:08.267
- Last modified
- 2026-08-12T05:17:31.927
- Weaknesses
- NVD-CWE-Other
Windows Print Spooler Remote Code Execution Vulnerability
| Metric | Score | Severity | Vector | Scored by |
|---|---|---|---|---|
| CVSS 3.1 | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H | [email protected] (Secondary) |
| CVSS 3.1 | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H | [email protected] (Secondary) |
| CVSS 2.0 | 9.3 | HIGH | AV:N/AC:M/Au:N/C:C/I:C/A:C | [email protected] (Primary) |
References
- http://packetstormsecurity.com/files/163349/Microsoft-PrintNightmare-Proof-Of-Concept.html (Third Party Advisory, VDB Entry)
- http://packetstormsecurity.com/files/163351/PrintNightmare-Windows-Spooler-Service-Remote-Code-Execution.html (Third Party Advisory, VDB Entry)
- http://packetstormsecurity.com/files/167261/Print-Spooler-Remote-DLL-Injection.html (Exploit, Third Party Advisory, VDB Entry)
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-1675 (Patch, Vendor Advisory)
- https://www.kb.cert.org/vuls/id/383432 (Third Party Advisory, US Government Resource)
- http://packetstormsecurity.com/files/163349/Microsoft-PrintNightmare-Proof-Of-Concept.html (Third Party Advisory, VDB Entry)
- http://packetstormsecurity.com/files/163351/PrintNightmare-Windows-Spooler-Service-Remote-Code-Execution.html (Third Party Advisory, VDB Entry)
- http://packetstormsecurity.com/files/167261/Print-Spooler-Remote-DLL-Injection.html (Exploit, Third Party Advisory, VDB Entry)
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-1675 (Patch, Vendor Advisory)
- https://www.kb.cert.org/vuls/id/383432 (Third Party Advisory, US Government Resource)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-1675 (US Government Resource)
This product uses the NVD API but is not endorsed or certified by the NVD.
Read on 2026-11-02T23:41:51.476Z under licence nvd-api-terms-of-use@ff2a5288 from https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2021-1675
CVE record
- Title (CNA)
- Windows Print Spooler Remote Code Execution Vulnerability
- Assigner
- microsoft
- State
- PUBLISHED
- Published
- 2021-06-08T22:46:11.000Z
- Updated
- 2026-08-12T03:55:44.254Z
- Problem types
- Elevation of Privilege
References
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-1675
- VU#383432
- http://packetstormsecurity.com/files/163349/Microsoft-PrintNightmare-Proof-Of-Concept.html
- http://packetstormsecurity.com/files/163351/PrintNightmare-Windows-Spooler-Service-Remote-Code-Execution.html
- http://packetstormsecurity.com/files/167261/Print-Spooler-Remote-DLL-Injection.html
Read on 2026-11-03T01:05:30.795Z under licence cve-terms-of-use@81bfa2f3 from https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2021/1xxx/CVE-2021-1675.json
Detection rules (SigmaHQ)
SigmaHQ rules whose own tags name this CVE. Each rule page shows the rule as its author published it.
- Windows Spooler Service Suspicious Binary Load (status test, level informational)
- CVE-2021-1675 Print Spooler Exploitation Filename Pattern (status test, level critical)
- Possible CVE-2021-1675 Print Spooler Exploitation (status test, level high)
- Potential PrintNightmare Exploitation Attempt (status test, level high)
- Antivirus PrinterNightmare CVE-2021-34527 Exploit Detection (status stable, level critical)
- Possible PrintNightmare Print Driver Install - CVE-2021-1675 (status stable, level medium)
- CVE-2021-1675 Print Spooler Exploitation IPC Access (status test, level critical)
- PrinterNightmare Mimikatz Driver Name (status test, level critical)
- Suspicious Printer Driver Empty Manufacturer (status test, level high)
- CVE-2021-1675 Print Spooler Exploitation (status test, level critical)
Sources and licences
CISA
Source: CISA Catalog of Known Exploited Vulnerabilities, version 2026.10.30, CC0 1.0. Use of this data does not imply endorsement by CISA or DHS.
National Vulnerability Database (NIST)
This product uses the NVD API but is not endorsed or certified by the NVD.
NVD API Terms of Use (NIST publications in the public domain, 17 U.S.C. 105)
CVE Program, The MITRE Corporation
Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation. CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy.
SigmaHQ
"Windows Spooler Service Suspicious Binary Load" by FPT.EagleEye, Thomas Patzke (improvements) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-emerging-threats/2021/Exploits/CVE-2021-1675/image_load_exploit_cve_2021_1675_spoolsv_dll_load.yml.
Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-LicenseSigmaHQ
"CVE-2021-1675 Print Spooler Exploitation Filename Pattern" by Florian Roth (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-emerging-threats/2021/Exploits/CVE-2021-1675/file_event_win_exploit_cve_2021_1675_printspooler.yml.
Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-LicenseSigmaHQ
"Possible CVE-2021-1675 Print Spooler Exploitation" by Florian Roth (Nextron Systems), KevTheHermit, fuzzyf10w, Tim Shelton (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-emerging-threats/2021/Exploits/CVE-2021-1675/win_exploit_cve_2021_1675_printspooler.yml.
Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-LicenseSigmaHQ
"Potential PrintNightmare Exploitation Attempt" by Bhabesh Raj (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-emerging-threats/2021/Exploits/CVE-2021-1675/file_delete_win_exploit_cve_2021_1675_print_nightmare.yml.
Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-LicenseSigmaHQ
"Antivirus PrinterNightmare CVE-2021-34527 Exploit Detection" by Sittikorn S, Nuttakorn T, Tim Shelton (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-emerging-threats/2021/Exploits/CVE-2021-1675/av_exploit_cve_2021_34527_print_nightmare.yml.
Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-LicenseSigmaHQ
"Possible PrintNightmare Print Driver Install - CVE-2021-1675" by @neu5ron (Nate Guagenti) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-emerging-threats/2021/Exploits/CVE-2021-1675/zeek_dce_rpc_exploit_cve_2021_1675_printnightmare_print_driver_install.yml.
Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-LicenseSigmaHQ
"CVE-2021-1675 Print Spooler Exploitation IPC Access" by INIT_6 (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-emerging-threats/2021/Exploits/CVE-2021-1675/win_security_exploit_cve_2021_1675_printspooler_security.yml.
Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-LicenseSigmaHQ
"PrinterNightmare Mimikatz Driver Name" by Markus Neis, @markus_neis, Florian Roth (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-emerging-threats/2021/Exploits/CVE-2021-1675/registry_event_cve_2021_1675_mimikatz_printernightmare_drivers.yml.
Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-LicenseSigmaHQ
"Suspicious Printer Driver Empty Manufacturer" by Florian Roth (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/registry/registry_set/registry_set_susp_printer_driver.yml.
Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-LicenseSigmaHQ
"CVE-2021-1675 Print Spooler Exploitation" by Florian Roth (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-emerging-threats/2021/Exploits/CVE-2021-1675/win_exploit_cve_2021_1675_printspooler_operational.yml.
Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-License
Cite this page
Dragons Eye Ransomware Tracker, "CVE-2021-1675: Microsoft Windows Print Spooler Remote Code Execution Vulnerability",
entity page, dataset version ref-3456e713e18e, updated 2026-11-02T23:39:54.475Z,
https://ransomware-tracker.com/cve/CVE-2021-1675 (accessed 2026-11-03).
Underlying source: CISA Catalog of Known Exploited Vulnerabilities, version 2026.10.30.
Underlying source: National Vulnerability Database (NIST), CVE API 2.0, record last modified 2026-08-12T05:17:31.927.
Underlying source: CVE List (CVE Program, The MITRE Corporation), record updated 2026-08-12T03:55:44.254Z.
Underlying source: SigmaHQ rule 02fb90de-c321-4e63-a6b9-25f4b03dfd14, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.
Underlying source: SigmaHQ rule 2131cfb3-8c12-45e8-8fa0-31f5924e9f07, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.
Underlying source: SigmaHQ rule 4e64668a-4da1-49f5-a8df-9e2d5b866718, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.
Underlying source: SigmaHQ rule 5b2bbc47-dead-4ef7-8908-0cf73fcbecbf, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.
Underlying source: SigmaHQ rule 6fe1719e-ecdf-4caf-bffe-4f501cb0a561, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.
Underlying source: SigmaHQ rule 7b33baef-2a75-4ca3-9da4-34f9a15382d8, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.
Underlying source: SigmaHQ rule 8fe1c584-ee61-444b-be21-e9054b229694, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.
Underlying source: SigmaHQ rule ba6b9e43-1d45-4d3c-a504-1043a64c8469, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.
Underlying source: SigmaHQ rule e0813366-0407-449a-9869-a2db1119dc41, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.
Underlying source: SigmaHQ rule f34d942d-c8c4-4f1f-b196-22471aecf10a, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.
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