CVE-2021-1637

20

FAUCET Score

CVE-2021-1637 is a Windows DNS Query Information Disclosure Vulnerability affecting various versions of Microsoft Windows, including Windows 10, 8.1, and Server 2012/2016. Rated Medium severity (CVSS 5.5), it allows a local attacker with low privileges to disclose sensitive information without user interaction. While the vulnerability has a low EPSS score and is not listed in CISA's KEV catalog, there is no public exploit code available (Metasploit, Nuclei, ExploitDB), and community discussion and media coverage are minimal.

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

5.5MEDIUM

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

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

NONE

Availability Impact

NONE

Exploitability Score

1.8

Impact Score

3.6

CvssVersion

3.1

Exploit Intelligence

EPSS Score

1.20%

Probability of exploitation in next 30 days

EPSS Percentile

65.0%

Percentile rank of EPSS score among Peer Group

As of 2026-07-28

Model: v2026.06.15

This CVE's current EPSS score of 0.0120 is in the 97th percentile among its peer group of 15,940 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.0 Bluesky, 0.0 Mastodon, and 0.1 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 (30)

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 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 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

Vendor Advisories (1)

microsoft2021-Jan/CVE-2021-1637Important

Windows DNS Query Information Disclosure Vulnerability

References

portal.msrc.microsoft.com / en-US/security-guidance/advisory/CVE-2021-1637

msrc.microsoft.com / update-guide/vulnerability/CVE-2021-1637