CVE-2021-1647

Microsoft Defender Remote Code Execution Vulnerability

Score

CVSS 3.1 7.8 High

Status

Analyzed - secure@microsoft.com

Published

2021-01-12

Last modified

2025-10-21

Known exploited (CISA KEV)

since 2021-11-03, action due 2021-11-17: Apply updates per vendor instructions.

Affected products

• Security Essentials (Microsoft)
• System Center Endpoint Protection (Microsoft)
• Windows Defender (Microsoft)

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-1647
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-1647
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-1647