CVE-2021-28340

26

FAUCET Score

CVE-2021-28340 is a Remote Procedure Call Runtime Remote Code Execution vulnerability affecting multiple versions of Microsoft Windows and Windows Server. With a CVSS score of 8.8 (High), it allows an authenticated attacker to execute arbitrary code remotely with low attack complexity and no user interaction. While not currently listed in CISA's KEV catalog or having public exploit code, its high EPSS score and FAUCET Risk Score of 85/100 indicate a significant potential for exploitation. Community discussion and media coverage suggest awareness, with BleepingComputer reporting its inclusion in the April 2021 Patch Tuesday.

Impacted Technologies

Vendor	Product	Version(s)	CPE
		Range not provided by sourceCPE matchmatch criteria	cpe:2.3:o:microsoft:windows_10:-:::::::*
		20h2CPE matchmatch criteria	cpe:2.3:o:microsoft:windows_10:20h2:::::::*
		1607CPE matchmatch criteria	cpe:2.3:o:microsoft:windows_10:1607:::::::*
		1803CPE matchmatch criteria	cpe:2.3:o:microsoft:windows_10:1803:::::::*
		1809CPE matchmatch criteria	cpe:2.3:o:microsoft:windows_10:1809:::::::*

CVSS Data

CVSS version used by this source: 3.1

8.8HIGH

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

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

Exploitability Score

2.8

Impact Score

5.9

CvssVersion

3.1

Exploit Intelligence

EPSS Score

2.54%

Probability of exploitation in next 30 days

EPSS Percentile

83.3%

Percentile rank of EPSS score among Peer Group

As of 2026-07-28

Model: v2026.06.15

This CVE's current EPSS score of 0.0254 is in the 82nd percentile among its peer group of 17,844 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.3 Bluesky, 0.1 Mastodon, and 0.2 GitHub mentions.

Media Mentions

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (42)

microsoftpatch availablevia nvd_reference

microsoftpatch availablevia msrc

Product: Windows 10 Version 1803 for 32-bit Systems

microsoftpatch availablevia msrc

Product: Windows 10 Version 1803 for x64-based Systems

microsoftpatch availablevia msrc

Product: Windows 10 Version 1803 for ARM64-based Systems

microsoftpatch availablevia msrc

Product: Windows 10 Version 1809 for 32-bit Systems

microsoftpatch availablevia msrc

Product: Windows 10 Version 1809 for x64-based Systems

microsoftpatch availablevia msrc

Product: Windows 10 Version 1809 for ARM64-based Systems

microsoftpatch availablevia msrc

Product: Windows Server 2019

microsoftpatch availablevia msrc

Product: Windows Server 2019 (Server Core installation)

microsoftpatch availablevia msrc

Product: Windows 10 Version 1909 for 32-bit Systems

microsoftpatch availablevia msrc

Product: Windows 10 Version 1909 for x64-based Systems

microsoftpatch availablevia msrc

Product: Windows 10 Version 1909 for ARM64-based Systems

microsoftpatch availablevia msrc

Product: Windows Server, version 1909 (Server Core installation)

microsoftpatch availablevia msrc

Product: Windows 10 Version 2004 for 32-bit Systems

microsoftpatch availablevia msrc

Product: Windows 10 Version 2004 for ARM64-based Systems

microsoftpatch availablevia msrc

Product: Windows 10 Version 2004 for x64-based Systems

microsoftpatch availablevia msrc

Product: Windows Server, version 2004 (Server Core installation)

microsoftpatch availablevia msrc

Product: Windows 10 Version 20H2 for x64-based Systems

microsoftpatch availablevia msrc

Product: Windows 10 Version 20H2 for 32-bit Systems

microsoftpatch availablevia msrc

Product: Windows 10 Version 20H2 for ARM64-based Systems

microsoftpatch availablevia msrc

Product: Windows Server, version 20H2 (Server Core Installation)

microsoftpatch availablevia msrc

Product: Windows 10 for 32-bit Systems

microsoftpatch availablevia msrc

Product: Windows 10 for x64-based Systems

microsoftpatch availablevia msrc

Product: Windows 10 Version 1607 for 32-bit Systems

microsoftpatch availablevia msrc

Product: Windows 10 Version 1607 for x64-based Systems

microsoftpatch availablevia msrc

Product: Windows Server 2016

microsoftpatch availablevia msrc

Product: Windows Server 2016 (Server Core installation)

microsoftpatch availablevia msrc

Product: Windows 7 for 32-bit Systems Service Pack 1

microsoftpatch availablevia msrc

Product: Windows 7 for x64-based Systems Service Pack 1

microsoftpatch availablevia msrc

Product: Windows Server 2008 R2 for x64-based Systems Service Pack 1

microsoftpatch availablevia msrc

Product: Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)

microsoftpatch availablevia msrc

Product: Windows 8.1 for 32-bit systems

microsoftpatch availablevia msrc

Product: Windows 8.1 for x64-based systems

microsoftpatch availablevia msrc

Product: Windows Server 2012 R2

microsoftpatch availablevia msrc

Product: Windows Server 2012 R2 (Server Core installation)

microsoftpatch availablevia msrc

Product: Windows RT 8.1

microsoftpatch availablevia msrc

Product: Windows Server 2008 for 32-bit Systems Service Pack 2

microsoftpatch availablevia msrc

Product: Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)

microsoftpatch availablevia msrc

Product: Windows Server 2008 for x64-based Systems Service Pack 2

microsoftpatch availablevia msrc

Product: Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)

microsoftpatch availablevia msrc

Product: Windows Server 2012

microsoftpatch availablevia msrc

Product: Windows Server 2012 (Server Core installation)

Vendor Advisories (1)

microsoft2021-Apr/CVE-2021-28340Important

Remote Procedure Call Runtime Remote Code Execution Vulnerability

References

portal.msrc.microsoft.com / en-US/security-guidance/advisory/CVE-2021-28340

PatchVendor Advisory