01 Record
CVE-2021-34527
Windows Print Spooler Remote Code Execution Vulnerability
HighKEVPUBLISHEDCNA: microsoft
CNA base score8.8 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C
02 Description
Windows Print Spooler Remote Code Execution Vulnerability
03 Exploitation and scoring
- Exploitation
- Exploited in the wild. Listed in the CISA Known Exploited Vulnerabilities catalog on 2021-11-03. Federal remediation due 2022-05-03. Known ransomware campaign use: reported by CISA.
- SSVC decision
- ExploitationactiveCISA reports credible evidence of active exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.
- EPSS probability
- 99.79% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 99.9% of scored records. A rank, not a probability.
- NVD base score
- 8.8 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- NVD analysis status
- Analyzed. NVD last modified this record on 2026-08-10.
- Red Hat severity
- No Red Hat rating. Red Hat rates the CVEs that affect its products.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2021-07-02 21:25Z5 YR AGO
- Last updated
- 2026-08-10 15:12Z2 MO AGO
- Reserved
- 2021-06-09
- Assigning CNA
- microsoft
- Record state
- PUBLISHED
- Severity
- High (CVSS 8.8)
- CNA CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C
- Weaknesses
- No CWE assigned
- Data version
- 5.2
- Document digest
- aa3d0daba3f061b7948aa047ffc9db81e571b0921067fdfdb31f737898b4aa7f
05 Affected products
VendorProductVersionsPlatforms
MicrosoftWindows 10 Version 180910.0.17763.0 to < 10.0.17763.2029, 10.0.0 to < 10.0.17763.202932-bit Systems, x64-based Systems, ARM64-based Systems
MicrosoftWindows 10 Version 21H210.0.19044.0 to < 10.0.19044.141532-bit Systems, ARM64-based Systems, x64-based Systems
MicrosoftWindows 10 Version 22H210.0.19045.0 to < 10.0.19045.225132-bit Systems, ARM64-based Systems, x64-based Systems
MicrosoftWindows 11 version 21H210.0.22000.0 to < 10.0.22000.318ARM64-based Systems, x64-based Systems
MicrosoftWindows 11 version 22H210.0.22621.0 to < 10.0.22621.674ARM64-based Systems, x64-based Systems
MicrosoftWindows Server 2008 R2 Service Pack 1 (Server Core installation)6.1.7601.0 to < 6.1.7601.25633x64-based Systems
MicrosoftWindows Server 2008 Service Pack 26.0.6003.0 to < 6.0.6003.2113832-bit Systems, x64-based Systems
MicrosoftWindows Server 2008 Service Pack 2 (Server Core installation)6.0.6003.0 to < 6.0.6003.2113832-bit Systems, x64-based Systems
MicrosoftWindows Server 2012 (Server Core installation)6.2.9200.0 to < 6.2.9200.23383x64-based Systems
MicrosoftWindows Server 2012 R2 (Server Core installation)6.3.9600.0 to < 6.3.9600.20046x64-based Systems
MicrosoftWindows Server 2016 (Server Core installation)10.0.14393.0 to < 10.0.14393.4470x64-based Systems
MicrosoftWindows Server 2019 (Server Core installation)10.0.17763.0 to < 10.0.17763.2029x64-based Systems
06 References
- msrc.microsoft.comWindows Print Spooler Remote Code Execution Vulnerabilityhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-34527
- www.cisa.govhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-34527
- www.vicarius.iohttps://www.vicarius.io/vsociety/posts/cve-2021-34527-printnightmare-detection-script
- www.vicarius.iohttps://www.vicarius.io/vsociety/posts/cve-2021-34527-printnightmare-mitigation-script
- portal.msrc.microsoft.comhttps://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34527
- packetstormsecurity.comhttp://packetstormsecurity.com/files/167261/Print-Spooler-Remote-DLL-Injection.html
- www.kb.cert.orghttps://www.kb.cert.org/vuls/id/383432