Microsofts Patch Tuesday-Updates vom Juni 2023 enthielten eine Sicherheitskorrektur für eine wichtige Schwachstelle im Windows-Kernel, aber die Lösung ist jedoch standardmäßig deaktiviert. Hier finden Sie alles, was Sie wissen müssen, sowie ein Skript, mit dem Sie den Patch für verschiedene Windows-Versionen aktivieren können.
Was ist CVE-2023-32019?
Laut Microsoft handelt es sich bei CVE-2023-32019 um eine Schwachstelle im Windows-Kernel, die mehrere Windows-Versionen betrifft, darunter die neuesten Versionen von Windows 10, Windows Server und Windows 11.
Bei erfolgreicher Ausnutzung kann ein Angreifer den dynamischen Speicher (Heap) eines mit Administratorrechten ausgeführten Prozesses einsehen, der auf einem Server läuft. Dafür sind keine Administrator- oder sonstigen erweiterten Berechtigungen erforderlich. Allerdings muss der Angreifer den Angriff mit einem anderen privilegierten Prozess koordinieren, der von einem anderen Benutzer auf dem System ausgeführt wird.
Trotz einer relativ bescheidenen CVSS-Basisbewertung von 4,7 von 10 hat Microsoft die Schwachstelle als besonders schwerwiegend eingestuft. Die in den Updates vom Juni 2023 enthaltene Korrektur erfordert jedoch einen zusätzlichen Schritt für die Aktivierung. Warum ist das so?
Warum ist die Korrektur für CVE-2023-32019 standardmäßig deaktiviert?
Die Support-Dokumentation von Microsoft enthält zwar nur wenige Details, aber das Unternehmen erklärt, dass die Behebung dieser Schwachstelle „potenzielle Ausfallzeiten“ verursachen könnte. Daher überlässt es Microsoft den Anwender:innen, die Lösung in Testumgebungen manuell zu aktivieren, und fordert sie auf, die Störungen genau zu beobachten, bevor sie die Lösung auf breiter Basis ausrollen.
Microsoft fügt noch hinzu, dass „diese Korrekturmaßnahme in einer zukünftigen Version standardmäßig aktiviert sein wird. Wir empfehlen Ihnen, diese Korrekturmaßnahme in Ihrer Umgebung zu überprüfen. Sobald sie validiert ist, sollten Sie die Korrektur so schnell wie möglich aktivieren.“
So aktivieren Sie das Patch für CVE-2023-32019 mit PowerShell
Um die Schwachstelle zu beheben, müssen Benutzer:innen einen Registrierungsschlüssel-Wert festlegen, der von der jeweiligen Windows-Version abhängt (jede Version erfordert einen anderen Schlüsselwert). Es genügt zu sagen, dass dieser zusätzliche Schritt zu Beschwerden geführt hat.
Um die Arbeit zu erleichtern, hat unser Software Product Engineer Kyle Bohlander das folgende Skript erstellt, das das Betriebssystem überprüft und die korrekte Änderung der Registrierung vornimmt.
Hinweis: Dieses Skript ist nicht nur auf NinjaOne-Benutzer:innen beschränkt. Es kann von jedem verwendet werden. Wie Microsoft jedoch rät, sollte diese Korrektur vor einer breiteren Anwendung auf Testrechnern implementiert werden, und wie üblich geschieht dies auf eigene Gefahr.
Skriptentwickler: Kyle Bohlander, Software Product Engineer bei NinjaOne
#Requires -Version 5.1
<#
.SYNOPSIS
This script will apply the registry fix suggested by microsoft for CVE-2023-32019 for the particular OS the computer is run on. Please note not all OS's have a fix to apply!
https://support.microsoft.com/en-au/topic/kb5028407-how-to-manage-the-vulnerability-associated-with-cve-2023-32019-bd6ed35f-48b1-41f6-bd19-d2d97270f080
.DESCRIPTION
This script will apply the registry fix suggested by microsoft for CVE-2023-32019 for the particular OS the computer is run on. Please note not all OS's have a fix to apply!
https://support.microsoft.com/en-au/topic/kb5028407-how-to-manage-the-vulnerability-associated-with-cve-2023-32019-bd6ed35f-48b1-41f6-bd19-d2d97270f080
.EXAMPLE
(No Parameters)
Checking Windows Version....
Desktop Windows Detected!
Windows 10 identified!
22H2 Detected!
Set Registry::HKEY_LOCAL_MACHINESYSTEMCurrentControlSetPoliciesMicrosoftFeatureManagementOverrides4103588492 to 1
Successfully set registry key!
PARAMETER: -Undo
Removes the registry key set for this fix. Script will error out if that registry key is not present.
.EXAMPLE
-Undo
Checking Windows Version....
Desktop Windows Detected!
Windows 10 identified!
22H2 Detected!
Undoing registry fix...
Successfully removed registry fix!
.OUTPUTS
None
.NOTES
Release: Initial Release (6/15/2023)
General notes
#>
[CmdletBinding()]
param (
[Parameter()]
[switch]$Undo
)
begin {
# Tests that the script is elevated
function Test-IsElevated {
$id = [System.Security.Principal.WindowsIdentity]::GetCurrent()
$p = New-Object System.Security.Principal.WindowsPrincipal($id)
$p.IsInRole([System.Security.Principal.WindowsBuiltInRole]::Administrator)
}
# We want the script to check if its running on a workstation or something else
function Test-IsWorkstation {
$OS = Get-CimInstance -ClassName Win32_OperatingSystem
return $OS.ProductType -eq 1
}
# This will set the registry key and any preceding keys needed
function Set-RegKey {
param (
$Path,
$Name,
$Value,
[ValidateSet("DWord", "QWord", "String", "ExpandedString", "Binary", "MultiString", "Unknown")]
$PropertyType = "DWord"
)
if (-not $(Test-Path -Path $Path)) {
# Check if path does not exist and create the path
New-Item -Path $Path -Force | Out-Null
}
if ((Get-ItemProperty -Path $Path -Name $Name -ErrorAction Ignore)) {
# Update property and print out what it was changed from and changed to
$CurrentValue = (Get-ItemProperty -Path $Path -Name $Name -ErrorAction Ignore).$Name
try {
Set-ItemProperty -Path $Path -Name $Name -Value $Value -Force -Confirm:$false -ErrorAction Stop | Out-Null
}
catch {
Write-Error "[Error] Unable to Set registry key for $Name please see below error!"
Write-Error $_
exit 1
}
Write-Host "$Path$Name changed from $CurrentValue to $($(Get-ItemProperty -Path $Path -Name $Name -ErrorAction Ignore).$Name)"
}
else {
# Create property with value
try {
New-ItemProperty -Path $Path -Name $Name -Value $Value -PropertyType $PropertyType -Force -Confirm:$false -ErrorAction Stop | Out-Null
}
catch {
Write-Error "[Error] Unable to Set registry key for $Name please see below error!"
Write-Error $_
exit 1
}
Write-Host "Set $Path$Name to $($(Get-ItemProperty -Path $Path -Name $Name -ErrorAction Ignore).$Name)"
}
}
# Is it Windows 10 or 11 or something else?
$WindowsVersion = [System.Environment]::OSVersion.Version.Major
# Current Build Number
$BuildNumber = [System.Environment]::OSVersion.Version.Build
# If Script Forms are used grab the input
if($env:Undo){$Undo = $env:Undo}
}
process {
# If not elevated error out. Admin priveledges are required to create HKLM registry keys
if (-not (Test-IsElevated)) {
Write-Error -Message "Access Denied. Please run with Administrator privileges."
exit 1
}
# Keeping the end user updated on the status
Write-Host "Checking Windows Version...."
if (Test-IsWorkstation) {
Write-Host "Desktop Windows Detected!"
# Depending on the version we'll want to check on a different set of build numbers
switch ($WindowsVersion) {
"10" {
switch ($BuildNumber) {
"22621" {
Write-Host "Windows 11 identified!"
Write-Host "22H2 Detected!"
$key = "Registry::HKEY_LOCAL_MACHINESYSTEMCurrentControlSetPoliciesMicrosoftFeatureManagementOverrides"
$name = "4237806220"
$value = "1"
}
"22000" {
Write-Host "Windows 11 identified!"
Write-Host "21H2 Detected!"
$key = "Registry::HKEY_LOCAL_MACHINESYSTEMCurrentControlSetPoliciesMicrosoftFeatureManagementOverrides"
$name = "4204251788"
$value = "1"
}
"19045" {
# This sets us up to set the registry key depending on the current build and version.
Write-Host "Windows 10 identified!"
Write-Host "22H2 Detected!"
$key = "Registry::HKEY_LOCAL_MACHINESYSTEMCurrentControlSetPoliciesMicrosoftFeatureManagementOverrides"
$name = "4103588492"
$value = "1"
}
"19044" {
Write-Host "Windows 10 identified!"
Write-Host "21H2 Detected!"
$key = "Registry::HKEY_LOCAL_MACHINESYSTEMCurrentControlSetPoliciesMicrosoftFeatureManagementOverrides"
$name = "4103588492"
$value = "1"
}
"19042" {
Write-Host "Windows 10 identified!"
Write-Host "20H2 Detected!"
$key = "Registry::HKEY_LOCAL_MACHINESYSTEMCurrentControlSetPoliciesMicrosoftFeatureManagementOverrides"
$name = "4103588492"
$value = "1"
}
"17763" {
Write-Host "Windows 10 identified!"
Write-Host "1809 Detected!"
$key = "Registry::HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlSession ManagerConfiguration Manager"
$name = "LazyRetryOnCommitFailure"
$value = "0"
}
"14393" {
Write-Host "Windows 10 identified!"
Write-Host "1607 Detected!"
$key = "Registry::HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlSession ManagerConfiguration Manager"
$name = "LazyRetryOnCommitFailure"
$value = "0"
}
default {
Write-Warning "Looks like you're either on an unsupported windows build or one not supported by this script? (Only Win 11 22H2 and 21H1 and Win 10 22H2,21H2,21H1,20H2,1809 and 1607 has a fix out!)"
Write-Warning "https://en.wikipedia.org/wiki/Windows_10_version_history"
Write-Warning "https://en.wikipedia.org/wiki/Windows_11_version_history"
Write-Error "[Error] This version of windows cannot be remediated by this script? Please verify this https://support.microsoft.com/en-au/topic/kb5028407-how-to-manage-the-vulnerability-associated-with-cve-2023-32019-bd6ed35f-48b1-41f6-bd19-d2d97270f080"
exit 1
}
}
}
default {
Write-Warning "Looks like you're on a version of windows not supported by this script? (Only Windows 10 and 11 have a fix out!)"
Write-Error "[Error] This version of windows appears to not be applicable or cannot be remediated by this script? Please verify this https://support.microsoft.com/en-au/topic/kb5028407-how-to-manage-the-vulnerability-associated-with-cve-2023-32019-bd6ed35f-48b1-41f6-bd19-d2d97270f080"
exit 1
}
}
}
else {
Write-Host "Windows Server Detected!"
if (Get-ComputerInfo | Select-Object OSName | Where-Object { $_.OSName -like "*2022*" }) {
$key = "Registry::HKEY_LOCAL_MACHINESYSTEMCurrentControlSetPoliciesMicrosoftFeatureManagementOverrides"
$name = "4137142924"
$value = "1"
}
else {
Write-Warning "Looks like you're on a version of windows not supported by this script? (Only Server 2022 has a fix out!)"
Write-Error "[Error] This version of windows appears to not be applicable or cannot be remediated by this script? Please verify this https://support.microsoft.com/en-au/topic/kb5028407-how-to-manage-the-vulnerability-associated-with-cve-2023-32019-bd6ed35f-48b1-41f6-bd19-d2d97270f080"
exit 1
}
}
if ($key -and -not $Undo) {
Set-RegKey -Path $key -Name $name -Value $value -PropertyType DWord
if ((Get-ItemPropertyValue -Path $key -Name $name -ErrorAction Ignore) -ne $value) {
Write-Error "[Error] Unable to set registry key? Is something blocking the script?"
exit 1
}
else {
Write-Host "Successfully set registry key!"
exit 0
}
}
elseif ($Undo) {
if (Get-ItemProperty -Path $key -ErrorAction Ignore) {
Write-Host "Undoing registry fix..."
Remove-ItemProperty -Path $key -Name $name
if (Get-ItemProperty -Path $key -ErrorAction Ignore) {
Write-Error "[Error] Unable to undo registry fix!"
exit 1
}
else {
Write-Host "Successfully removed registry fix!"
exit 0
}
}
else {
Write-Error "[Error] Registry Key not found? Did you already undo it?"
exit 1
}
}else{
Write-Error "[Error] Unable to find registry key to set!"
exit 1
}
}
end {
$ScriptName = "CVE-2023-32019 Remediation"
$ScriptVariables = @(
[PSCustomObject]@{
name = "Undo"
calculatedName = "undo"
required = $false
defaultValue = $false
valueType = "CHECKBOX"
valueList = $null
description = "Whether or not to undo the registry fix."
}
)
}