# CVE-2021-1647: Microsoft Defender Remote Code Execution Vulnerability > CVE-2021-1647: Microsoft Defender Remote Code Execution Vulnerability. CVSS 7.8 (CVSS 3.1), in CISA KEV. Canonical: https://rewindex.com/cve/CVE-2021-1647 Last updated: 2025-10-21T23:35:30Z - Published: 2021-01-12 19:42 UTC · Updated: 2025-10-21 23:35 UTC · Assigner: microsoft - CVSS: 7.8 (CVSS 3.1) · Severity: High · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C - EPSS: 39.7%, 99th percentile (scored 2026-10-25) - CISA KEV: yes, added 2021-11-03, federal due date 2021-11-17, ransomware use: Unknown ## Description Microsoft Defender Remote Code Execution Vulnerability ## CISA required action Apply updates per vendor instructions. ## Affected vendors and products - Microsoft: Microsoft Security Essentials - Microsoft: Microsoft System Center 2012 Endpoint Protection - Microsoft: Microsoft System Center 2012 R2 Endpoint Protection - Microsoft: Microsoft System Center Endpoint Protection - Microsoft: Windows Defender ## References - [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2021-1647) - [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2021-1647) - [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-1647](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-1647) --- _Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_ --- Canonical: https://rewindex.com/cve/CVE-2021-1647 · Markdown: https://rewindex.com/cve/CVE-2021-1647.md · JSON: https://rewindex.com/api/v1/cves/CVE-2021-1647 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T04:04:32.781Z