CVE-2021-34527 — Microsoft Windows Print Spooler Remote Code Execution Vulnerability
Overview
Microsoft Windows Print Spooler contains an unspecified vulnerability due to the Windows Print Spooler service improperly performing privileged file operations. Successful exploitation allows an attacker to perform remote code execution with SYSTEM privileges. The vulnerability is also known under the moniker of PrintNightmare.
Vulnerability details
- CVE ID
- CVE-2021-34527
- Vulnerability
- Microsoft Windows Print Spooler Remote Code Execution Vulnerability
- Vendor
- Microsoft
- Affected products
- Microsoft: Windows
- Severity
- HIGH
- Exploitation status
- Actively exploited in the wild (CISA KEV)
- Published
- 2021-11-03
Remediation guidance
CVE-2021-34527 is in CISA's Known Exploited Vulnerabilities (KEV) catalog — U.S. federal civilian agencies are required to remediate it under Binding Operational Directive 22-01. Treat it as a priority for every environment.
Apply the vendor's official security update for Microsoft the affected product as soon as possible. Where a patch is unavailable, apply vendor mitigations or isolate/segment exposed systems.
Hunt for indicators of compromise tied to this vulnerability and confirm logging/EDR coverage on affected assets.
Authoritative references
Remediate CVE-2021-34527 — and stay ahead of the next one
CVE-2021-34527 is listed in the CISA KEV catalog as actively exploited — treat remediation as urgent. Scan your domain free to see whether CVE-2021-34527 and other Microsoft issues affect you and get a prioritized remediation report (full report from ₹999) — or stream the full feed of 1,600+ actively-exploited CVEs straight into your SOC.
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