Important CVSS 6.8 EPSS 0.0542 2019-10 archive

Executive Summary

An information disclosure vulnerability exists when the Windows Hyper-V Network Switch on a host operating system fails to properly validate input from an authenticated user on a guest operating system. To exploit the vulnerability, an attacker on a guest operating system could run a specially crafted application that could cause the Hyper-V host operating system to disclose memory information. An attacker who successfully exploited the vulnerability could gain access to information on the Hyper-V host operating system. The security update addresses the vulnerability by correcting how the Windows Hyper-V Network Switch validates guest operating system user input.

Overview

6.8
CVSS MEDIUM
Important
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
Category Information Disclosure
Released Oct 8 2019
Last Updated Oct 8 2019
Publicly Disclosed No
CISA KEV Not Listed
Known Exploits None Known
EPSS Score 0.0542 — 0.91669 percentile

CVSS Vector

ATTACK VECTOR
Network
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
High
USER INTERACTION
None
SCOPE
Changed
Temporal Score: 6.1

EPSS Score

0.0542
probability of exploitation in the next 30 days
0.91669 percentile - updated 2026-06-20
View on FIRST.org

Affected Products

7 affected products
Product KB Article Severity Impact Restart Required
Windows 10 Version 1703 for x64-based Systems 4520010 (Security Update) Important Information Disclosure Yes
Windows 10 Version 1709 for x64-based Systems 4520004 (Security Update) Important Information Disclosure Yes
Windows 10 Version 1803 for x64-based Systems 4520008 (Security Update) Important Information Disclosure Yes
Windows 10 Version 1809 for x64-based Systems 4519338 (Security Update) Important Information Disclosure Yes
Windows Server 2019 4519338 (Security Update) Important Information Disclosure Yes
Windows Server 2019 (Server Core installation) 4519338 (Security Update) Important Information Disclosure Yes
Windows Server, version 1803 (Server Core Installation) 4520008 (Security Update) Important Information Disclosure Yes

Patches

4 patches
Article Type Restart
4520010 Security Update Yes
4520004 Security Update Yes
4520008 Security Update Yes
4519338 Security Update Yes

Known Exploits

Acknowledgments

VictorV from 360 Security, Vulcan Team