CVE-2018-8438 — Windows Hyper-V Denial of Service Vulnerability

Executive Summary

A denial of service vulnerability exists when Microsoft Hyper-V Network Switch on a host server fails to properly validate input from a privileged user on a guest operating system. An attacker who successfully exploited the vulnerability could cause the host server to crash. To exploit the vulnerability, an attacker who already has a privileged account on a guest operating system, running as a virtual machine, could run a specially crafted application that causes a host machine to crash. The update addresses the vulnerability by modifying how virtual machines access the Hyper-V Network Switch.

Overview

5.8

CVSS MEDIUM

Important

MS Severity

Not Exploited

MS Exploit Status

Less Likely

MS Exploit Likelihood

Category Denial of Service

Released Sep 11 2018

Last Updated Sep 11 2018

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

CVSS Vector

ATTACK VECTOR

Network

ATTACK COMPLEXITY

High

PRIVILEGES REQUIRED

High

USER INTERACTION

None

SCOPE

Changed

CONFIDENTIALITY

None

INTEGRITY

None

AVAILABILITY

High

EXPLOIT CODE MATURITY

Proof-of-Concept

REMEDIATION LEVEL

Official Fix

REPORT CONFIDENCE

Confirmed

Temporal Score: 5.2

EPSS Score

No EPSS score available for this CVE.

View on FIRST.org

Affected Products

15 affected products

Product	KB Article	Severity	Impact	Restart Required
Windows 10 for 32-bit Systems	`4457132 (Security Update)`	Important	Denial of Service	Yes
Windows 10 for x64-based Systems	`4457132 (Security Update)`	Important	Denial of Service	Yes
Windows 10 Version 1607 for 32-bit Systems	`4457131 (Security Update)`	Important	Denial of Service	Yes
Windows 10 Version 1607 for x64-based Systems	`4457131 (Security Update)`	Important	Denial of Service	Yes
Windows 10 Version 1703 for 32-bit Systems	`4457138 (Security Update)`	Important	Denial of Service	Yes
Windows 10 Version 1703 for x64-based Systems	`4457138 (Security Update)`	Important	Denial of Service	Yes
Windows 10 Version 1709 for 32-bit Systems	`4457142 (Security Update)`	Important	Denial of Service	Yes
Windows 10 Version 1709 for x64-based Systems	`4457142 (Security Update)`	Important	Denial of Service	Yes
Windows 10 Version 1803 for 32-bit Systems	`4457128 (Security Update)`	Important	Denial of Service	Yes
Windows 10 Version 1803 for x64-based Systems	`4457128 (Security Update)`	Important	Denial of Service	Yes
Windows 8.1 for 32-bit systems 4457129 (Monthly Rollup) 4457143 (Security Only) Important Denial of Service 4343898 Base: 5.8 Temporal: 5.2 Vector: CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:C/C:N/I:N/A:H/E:P/RL:O/RC:C Yes None Windows 8.1 for x64-based systems 4457129 (Monthly Rollup) 4457143 (Security Only) Important Denial of Service 4343898 Base: 5.8 Temporal: 5.2 Vector: CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:C/C:N/I:N/A:H/E:P/RL:O/RC:C Yes None Windows RT 8.1	`4457129 (Monthly Rollup)`	Important	Denial of Service	Yes
Windows Server 2012 R2 4457129 (Monthly Rollup) 4457143 (Security Only) Important Denial of Service 4343898 Base: 5.8 Temporal: 5.2 Vector: CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:C/C:N/I:N/A:H/E:P/RL:O/RC:C Yes None Windows Server 2012 R2 (Server Core installation) 4457129 (Monthly Rollup) 4457143 (Security Only) Important Denial of Service 4343898 Base: 5.8 Temporal: 5.2 Vector: CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:C/C:N/I:N/A:H/E:P/RL:O/RC:C Yes None Windows Server 2016	`4457131 (Security Update)`	Important	Denial of Service	Yes
Windows Server 2016 (Server Core installation)	`4457131 (Security Update)`	Important	Denial of Service	Yes
Windows Server, version 1709 (Server Core Installation)	`4457142 (Security Update)`	Important	Denial of Service	Yes
Windows Server, version 1803 (Server Core Installation)	`4457128 (Security Update)`	Important	Denial of Service	Yes

Patches

6 patches

Article	Type	Restart
`4457132`	Security Update	Yes
`4457131`	Security Update	Yes
`4457138`	Security Update	Yes
`4457142`	Security Update	Yes
`4457128`	Security Update	Yes
`4457129`	Monthly Rollup	Yes

Known Exploits

No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.

Acknowledgments

Deepti Bhardwaj, Microsoft Base Kernel Team
Nick Freeman

References

MSRC Advisory MITRE NVD