Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2021-1647

81
FAUCET Score

CVE-2021-1647 is a critical remote code execution vulnerability affecting Microsoft Defender, allowing an attacker to execute arbitrary code with elevated privileges. With a CVSS score of 7.8 (HIGH), it presents a significant risk due to its low attack complexity and high impact on confidentiality, integrity, and availability. This vulnerability is actively exploited in the wild, as confirmed by its presence in the CISA KEV catalog, and has garnered substantial community attention and media coverage. Despite active exploitation, no public exploit code is currently available on platforms like Metasploit or ExploitDB.

Impacted Technologies

VendorProductVersion(s)CPE
Range not provided by sourceCPE matchmatch criteria
cpe:2.3:a:microsoft:windows_defender:-:*:*:*:*:*:*:*
Range not provided by sourceCPE matchmatch criteria
cpe:2.3:a:microsoft:security_essentials:-:*:*:*:*:*:*:*
Range not provided by sourceCPE matchmatch criteria
cpe:2.3:a:microsoft:system_center_endpoint_protection:-:*:*:*:*:*:*:*
2012CPE matchmatch criteria
cpe:2.3:a:microsoft:system_center_endpoint_protection:2012:-:*:*:*:*:*:*
2012CPE matchmatch criteria
cpe:2.3:a:microsoft:system_center_endpoint_protection:2012:r2:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

7.8HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
1.8
Impact Score
5.9
CvssVersion
3.1

Exploit Intelligence

EPSS Score
39.65%
Probability of exploitation in next 30 days
EPSS Percentile
98.5%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
Added to KEV · Nov 3, 2021
This CVE's current EPSS score of 0.3965 is in the 100th percentile among its peer group of 17,061 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.2 Bluesky, 0.1 Mastodon, and 0.2 GitHub mentions.

Media Mentions

The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (1)

microsoftpatch availablevia nvd_reference
View patch

Vendor Advisories (1)

microsoft2021-Jan/CVE-2021-1647Critical

Microsoft Defender Remote Code Execution Vulnerability

Jan 12, 2021

References

cisa.gov / known-exploited-vulnerabilities-catalog
US Government Resource
portal.msrc.microsoft.com / en-US/security-guidance/advisory/CVE-2021-1647
PatchVendor Advisory
msrc.microsoft.com / update-guide/vulnerability/CVE-2021-1647
PatchVendor Advisory