Introduction
Microsoft has developed a sample PowerShell script that can help you automate updating the Windows Recovery Environment (WinRE) on deployed devices to address the security vulnerabilities in CVE-2024-20666.
Sample PowerShell script
The sample PowerShell script was developed by the Microsoft product team to help automate the updating of WinRE images on supported Windows 10 and Windows 11 devices. Run the script with Administrator credentials in PowerShell on the affected devices. There are two scripts available—which script you should use depends on the version of Windows you are running. Please use the appropriate version for your environment.
PatchWinREScript_2004plus.ps1 (Recommended)
This script is for Windows 10, version 2004 and later versions, including Windows 11. We recommend that you use this version of the script, because it is more robust but uses features available only on Windows 10, version 2004 and later versions.
################################################################################################
#
# Copyright (c) Microsoft Corporation.
# Licensed under the MIT License.
#
# THE SOFTWARE IS PROVIDED *AS IS*, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
#
################################################################################################
Param (
[Parameter(HelpMessage="Work Directory for patch WinRE")][string]$workDir="",
[Parameter(Mandatory=$true,HelpMessage="Path of target package")][string]$packagePath
)
# ------------------------------------
# Help functions
# ------------------------------------
# Log message
function LogMessage([string]$message)
{
$message = "$([DateTime]::Now) - $message"
Write-Host $message
}
function IsTPMBasedProtector
{
$DriveLetter = $env:SystemDrive
LogMessage("Checking BitLocker status")
$BitLocker = Get-WmiObject -Namespace "Root\cimv2\Security\MicrosoftVolumeEncryption" -Class "Win32_EncryptableVolume" -Filter "DriveLetter = '$DriveLetter'"
if(-not $BitLocker)
{
LogMessage("No BitLocker object")
return $False
}
$protectionEnabled = $False
switch ($BitLocker.GetProtectionStatus().protectionStatus){
("0"){
LogMessage("Unprotected")
break
}
("1"){
LogMessage("Protected")
$protectionEnabled = $True
break
}
("2"){
LogMessage("Uknown")
break
}
default{
LogMessage("NoReturn")
break
}
}
if (!$protectionEnabled)
{
LogMessage("Bitlocker isn’t enabled on the OS")
return $False
}
$ProtectorIds = $BitLocker.GetKeyProtectors("0").volumekeyprotectorID
$return = $False
foreach ($ProtectorID in $ProtectorIds){
$KeyProtectorType = $BitLocker.GetKeyProtectorType($ProtectorID).KeyProtectorType
switch($KeyProtectorType){
"1"{
LogMessage("Trusted Platform Module (TPM)")
$return = $True
break
}
"4"{
LogMessage("TPM And PIN")
$return = $True
break
}
"5"{
LogMessage("TPM And Startup Key")
$return = $True
break
}
"6"{
LogMessage("TPM And PIN And Startup Key")
$return = $True
break
}
default {break}
}#endSwitch
}#EndForeach
if ($return)
{
LogMessage("Has TPM-based protector")
}
else
{
LogMessage("Doesn't have TPM-based protector")
}
return $return
}
function SetRegistrykeyForSuccess
{
reg add HKLM\SOFTWARE\Microsoft\PushButtonReset /v WinREPathScriptSucceed_CVE_2024_20666 /d 1 /f
}
function TargetfileVersionExam([string]$mountDir)
{
# Exam target binary
$targetBinary=$mountDir + "\Windows\System32\winload.efi"
LogMessage("TargetFile: " + $targetBinary)
$realNTVersion = [Diagnostics.FileVersionInfo]::GetVersionInfo($targetBinary).ProductVersion
$versionString = "$($realNTVersion.Split('.')[0]).$($realNTVersion.Split('.')[1])"
$fileVersion = $($realNTVersion.Split('.')[2])
$fileRevision = $($realNTVersion.Split('.')[3])
LogMessage("Target file version: " + $realNTVersion)
if (!($versionString -eq "10.0"))
{
LogMessage("Not Windows 10 or later")
return $False
}
$hasUpdated = $False
#Windows 10, version 1507 10240.20400
#Windows 10, version 1607 14393.6610
#Windows 10, version 1809 17763.5322
#Windows 10, version 2004 1904X.3920
#Windows 11, version 21H2 22000.2710
#Windows 11, version 22H2 22621.3000
switch ($fileVersion) {
"10240" {
LogMessage("Windows 10, version 1507")
if ($fileRevision -ge 20400)
{
LogMessage("Windows 10, version 1507 with revision " + $fileRevision + " >= 20400, updates have been applied")
$hasUpdated = $True
}
break
}
"14393" {
LogMessage("Windows 10, version 1607")
if ($fileRevision -ge 6610)
{
LogMessage("Windows 10, version 1607 with revision " + $fileRevision + " >= 6610, updates have been applied")
$hasUpdated = $True
}
break
}
"17763" {
LogMessage("Windows 10, version 1809")
if ($fileRevision -ge 5322)
{
LogMessage("Windows 10, version 1809 with revision " + $fileRevision + " >= 5322, updates have been applied")
$hasUpdated = $True
}
break
}
"19041" {
LogMessage("Windows 10, version 2004")
if ($fileRevision -ge 3920)
{
LogMessage("Windows 10, version 2004 with revision " + $fileRevision + " >= 3920, updates have been applied")
$hasUpdated = $True
}
break
}
"22000" {
LogMessage("Windows 11, version 21H2")
if ($fileRevision -ge 2710)
{
LogMessage("Windows 11, version 21H2 with revision " + $fileRevision + " >= 2710, updates have been applied")
$hasUpdated = $True
}
break
}
"22621" {
LogMessage("Windows 11, version 22H2")
if ($fileRevision -ge 3000)
{
LogMessage("Windows 11, version 22H2 with revision " + $fileRevision + " >= 3000, updates have been applied")
$hasUpdated = $True
}
break
}
default {
LogMessage("Warning: unsupported OS version")
}
}
return $hasUpdated
}
function PatchPackage([string]$mountDir, [string]$packagePath)
{
# Exam target binary
$hasUpdated =TargetfileVersionExam($mountDir)
if ($hasUpdated)
{
LogMessage("The update has already been added to WinRE")
SetRegistrykeyForSuccess
return $False
}
# Add package
LogMessage("Apply package:" + $packagePath)
Dism /Add-Package /Image:$mountDir /PackagePath:$packagePath
if ($LASTEXITCODE -eq 0)
{
LogMessage("Successfully applied the package")
}
else
{
LogMessage("Applying the package failed with exit code: " + $LASTEXITCODE)
return $False
}
# Cleanup recovery image
LogMessage("Cleanup image")
Dism /image:$mountDir /cleanup-image /StartComponentCleanup /ResetBase
if ($LASTEXITCODE -eq 0)
{
LogMessage("Cleanup image succeed")
}
else
{
LogMessage("Cleanup image failed: " + $LASTEXITCODE)
return $False
}
return $True
}
# ------------------------------------
# Execution starts
# ------------------------------------
# Check breadcrumb
if (Test-Path HKLM:\Software\Microsoft\PushButtonReset)
{
$values = Get-ItemProperty -Path HKLM:\Software\Microsoft\PushButtonReset
if (!(-not $values))
{
if (Get-Member -InputObject $values -Name WinREPathScriptSucceed_CVE_2024_20666)
{
$value = Get-ItemProperty -Path HKLM:\Software\Microsoft\PushButtonReset -Name WinREPathScriptSucceed_CVE_2024_20666
if ($value.WinREPathScriptSucceed_CVE_2024_20666 -eq 1)
{
LogMessage("This script was previously run successfully")
exit 1
}
}
}
}
if ([string]::IsNullorEmpty($workDir))
{
LogMessage("No input for mount directory")
LogMessage("Use default path from temporary directory")
$workDir = [System.IO.Path]::GetTempPath()
}
LogMessage("Working Dir: " + $workDir)
$name = "9f8131ee-878f-4525-bf31-e446aac3016a_Mount"
$mountDir = Join-Path $workDir $name
LogMessage("MountDir: " + $mountdir)
# Delete existing mount directory
if (Test-Path $mountDir)
{
LogMessage("Mount directory: " + $mountDir + " already exists")
LogMessage("Try to unmount it")
Dism /unmount-image /mountDir:$mountDir /discard
if (!($LASTEXITCODE -eq 0))
{
LogMessage("Warning: unmount failed: " + $LASTEXITCODE)
}
LogMessage("Delete existing mount direcotry " + $mountDir)
Remove-Item $mountDir -Recurse
}
# Create mount directory
LogMessage("Create mount directory " + $mountDir)
New-Item -Path $mountDir -ItemType Directory
# Set ACL for mount directory
LogMessage("Set ACL for mount directory")
icacls $mountDir /inheritance:r
icacls $mountDir /grant:r SYSTEM:"(OI)(CI)(F)"
icacls $mountDir /grant:r *S-1-5-32-544:"(OI)(CI)(F)"
# Mount WinRE
LogMessage("Mount WinRE:")
reagentc /mountre /path $mountdir
if ($LASTEXITCODE -eq 0)
{
# Patch WinRE
if (PatchPackage -mountDir $mountDir -packagePath $packagePath)
{
$hasUpdated = TargetfileVersionExam($mountDir)
if ($hasUpdated)
{
LogMessage("After patch, find expected version for target file")
}
else
{
LogMessage("Warning: After applying the patch, unexpected version found for the target file")
}
LogMessage("Patch succeed, unmount to commit change")
Dism /unmount-image /mountDir:$mountDir /commit
if (!($LASTEXITCODE -eq 0))
{
LogMessage("Unmount failed: " + $LASTEXITCODE)
exit 1
}
else
{
if ($hasUpdated)
{
if (IsTPMBasedProtector)
{
# Disable WinRE and re-enable it to let new WinRE be trusted by BitLocker
LogMessage("Disable WinRE")
reagentc /disable
LogMessage("Re-enable WinRE")
reagentc /enable
reagentc /info
}
# Leave a breadcrumb indicates the script has succeed
SetRegistrykeyForSuccess
}
}
}
else
{
LogMessage("Patch failed or is not applicable, discard unmount")
Dism /unmount-image /mountDir:$mountDir /discard
if (!($LASTEXITCODE -eq 0))
{
LogMessage("Unmount failed: " + $LASTEXITCODE)
exit 1
}
}
}
else
{
LogMessage("Mount failed: " + $LASTEXITCODE)
}
# Cleanup Mount directory in the end
LogMessage("Delete mount direcotry")
Remove-Item $mountDir -Recurse
PatchWinREScript_General.ps1
This script is for Windows 10, version 1909 and earlier versions, but executes on all versions of Windows 10 and Windows 11.
################################################################################################
#
# Copyright (c) Microsoft Corporation.
# Licensed under the MIT License.
#
# THE SOFTWARE IS PROVIDED *AS IS*, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
#
################################################################################################
Param (
[Parameter(HelpMessage="Work Directory for patch WinRE")][string]$workDir="",
[Parameter(Mandatory=$true,HelpMessage="Path of target package")][string]$packagePath
)
# ------------------------------------
# Help functions
# ------------------------------------
# Log message
function LogMessage([string]$message)
{
$message = "$([DateTime]::Now) - $message"
Write-Host $message
}
function IsTPMBasedProtector
{
$DriveLetter = $env:SystemDrive
LogMessage("Checking BitLocker status")
$BitLocker = Get-WmiObject -Namespace "Root\cimv2\Security\MicrosoftVolumeEncryption" -Class "Win32_EncryptableVolume" -Filter "DriveLetter = '$DriveLetter'"
if(-not $BitLocker)
{
LogMessage("No BitLocker object")
return $False
}
$protectionEnabled = $False
switch ($BitLocker.GetProtectionStatus().protectionStatus){
("0"){
LogMessage("Unprotected")
break
}
("1"){
LogMessage("Protected")
$protectionEnabled = $True
break
}
("2"){
LogMessage("Uknown")
break
}
default{
LogMessage("NoReturn")
break
}
}
if (!$protectionEnabled)
{
LogMessage("Bitlocker isn’t enabled on the OS")
return $False
}
$ProtectorIds = $BitLocker.GetKeyProtectors("0").volumekeyprotectorID
$return = $False
foreach ($ProtectorID in $ProtectorIds){
$KeyProtectorType = $BitLocker.GetKeyProtectorType($ProtectorID).KeyProtectorType
switch($KeyProtectorType){
"1"{
LogMessage("Trusted Platform Module (TPM)")
$return = $True
break
}
"4"{
LogMessage("TPM And PIN")
$return = $True
break
}
"5"{
LogMessage("TPM And Startup Key")
$return = $True
break
}
"6"{
LogMessage("TPM And PIN And Startup Key")
$return = $True
break
}
default {break}
}#endSwitch
}#EndForeach
if ($return)
{
LogMessage("Has TPM-based protector")
}
else
{
LogMessage("Doesn't have TPM-based protector")
}
return $return
}
function SetRegistrykeyForSuccess
{
reg add HKLM\SOFTWARE\Microsoft\PushButtonReset /v WinREPathScriptSucceed_CVE_2024_20666 /d 1 /f
}
function TargetfileVersionExam([string]$mountDir)
{
# Exam target binary
$targetBinary=$mountDir + "\Windows\System32\winload.efi"
LogMessage("TargetFile: " + $targetBinary)
$realNTVersion = [Diagnostics.FileVersionInfo]::GetVersionInfo($targetBinary).ProductVersion
$versionString = "$($realNTVersion.Split('.')[0]).$($realNTVersion.Split('.')[1])"
$fileVersion = $($realNTVersion.Split('.')[2])
$fileRevision = $($realNTVersion.Split('.')[3])
LogMessage("Target file version: " + $realNTVersion)
if (!($versionString -eq "10.0"))
{
LogMessage("Not Windows 10 or later")
return $False
}
$hasUpdated = $False
#Windows 10, version 1507 10240.20400
#Windows 10, version 1607 14393.6610
#Windows 10, version 1809 17763.5322
#Windows 10, version 2004 1904X.3920
#Windows 11, version 21H2 22000.2710
#Windows 11, version 22H2 22621.3000
switch ($fileVersion) {
"10240" {
LogMessage("Windows 10, version 1507")
if ($fileRevision -ge 20400)
{
LogMessage("Windows 10, version 1507 with revision " + $fileRevision + " >= 20400, updates have been applied")
$hasUpdated = $True
}
break
}
"14393" {
LogMessage("Windows 10, version 1607")
if ($fileRevision -ge 6610)
{
LogMessage("Windows 10, version 1607 with revision " + $fileRevision + " >= 6610, updates have been applied")
$hasUpdated = $True
}
break
}
"17763" {
LogMessage("Windows 10, version 1809")
if ($fileRevision -ge 5322)
{
LogMessage("Windows 10, version 1809 with revision " + $fileRevision + " >= 5322, updates have been applied")
$hasUpdated = $True
}
break
}
"19041" {
LogMessage("Windows 10, version 2004")
if ($fileRevision -ge 3920)
{
LogMessage("Windows 10, version 2004 with revision " + $fileRevision + " >= 3920, updates have been applied")
$hasUpdated = $True
}
break
}
"22000" {
LogMessage("Windows 11, version 21H2")
if ($fileRevision -ge 2710)
{
LogMessage("Windows 11, version 21H2 with revision " + $fileRevision + " >= 2710, updates have been applied")
$hasUpdated = $True
}
break
}
"22621" {
LogMessage("Windows 11, version 22H2")
if ($fileRevision -ge 3000)
{
LogMessage("Windows 11, version 22H2 with revision " + $fileRevision + " >= 3000, updates have been applied")
$hasUpdated = $True
}
break
}
default {
LogMessage("Warning: unsupported OS version")
}
}
return $hasUpdated
}
function PatchPackage([string]$mountDir, [string]$packagePath)
{
# Exam target binary
$hasUpdated = TargetfileVersionExam($mountDir)
if ($hasUpdated)
{
LogMessage("The update has already been added to WinRE")
SetRegistrykeyForSuccess
return $False
}
# Add package
LogMessage("Apply package:" + $packagePath)
Dism /Add-Package /Image:$mountDir /PackagePath:$packagePath
if ($LASTEXITCODE -eq 0)
{
LogMessage("Successfully applied the package")
}
else
{
LogMessage("Applying the package failed with exit code: " + $LASTEXITCODE)
return $False
}
# Cleanup recovery image
LogMessage("Cleanup image")
Dism /image:$mountDir /cleanup-image /StartComponentCleanup /ResetBase
if ($LASTEXITCODE -eq 0)
{
LogMessage("Cleanup image succeed")
}
else
{
LogMessage("Cleanup image failed: " + $LASTEXITCODE)
return $False
}
return $True
}
# ------------------------------------
# Execution starts
# ------------------------------------
# Check breadcrumb
if (Test-Path HKLM:\Software\Microsoft\PushButtonReset)
{
$values = Get-ItemProperty -Path HKLM:\Software\Microsoft\PushButtonReset
if (!(-not $values))
{
if (Get-Member -InputObject $values -Name WinREPathScriptSucceed_CVE_2024_20666)
{
$value = Get-ItemProperty -Path HKLM:\Software\Microsoft\PushButtonReset -Name WinREPathScriptSucceed_CVE_2024_20666
if ($value.WinREPathScriptSucceed_CVE_2024_20666 -eq 1)
{
LogMessage("This script was previously run successfully")
exit 1
}
}
}
}
# Get WinRE info
$WinREInfo = Reagentc /info
$findLocation = $False
foreach ($line in $WinREInfo)
{
$params = $line.Split(':')
if ($params.count -le 1)
{
continue
}
if ($params[1].Lenght -eq 0)
{
continue
}
$content = $params[1].Trim()
if ($content.Lenght -eq 0)
{
continue
}
$index = $content.IndexOf("\\?\")
if ($index -ge 0)
{
LogMessage("Find \\?\ at " + $index + " for [" + $content + "]")
$WinRELocation = $content
$findLocation = $True
}
}
if (!$findLocation)
{
LogMessage("WinRE Disabled")
exit 1
}
LogMessage("WinRE Enabled. WinRE location:" + $WinRELocation)
$WinREFile = $WinRELocation + "\winre.wim"
if ([string]::IsNullorEmpty($workDir))
{
LogMessage("No input for mount directory")
LogMessage("Use default path from temporary directory")
$workDir = [System.IO.Path]::GetTempPath()
}
LogMessage("Working Dir: " + $workDir)
$name = "9f8131ee-878f-4525-bf31-e446aac3016a_Mount"
$mountDir = Join-Path $workDir $name
LogMessage("MountDir: " + $mountdir)
# Delete existing mount directory
if (Test-Path $mountDir)
{
LogMessage("Mount directory: " + $mountDir + " already exists")
LogMessage("Try to unmount it")
Dism /unmount-image /mountDir:$mountDir /discard
if (!($LASTEXITCODE -eq 0))
{
LogMessage("Warning: unmount failed: " + $LASTEXITCODE)
}
LogMessage("Delete existing mount direcotry " + $mountDir)
Remove-Item $mountDir -Recurse
}
# Create mount directory
LogMessage("Create mount directory " + $mountDir)
New-Item -Path $mountDir -ItemType Directory
# Set ACL for mount directory
LogMessage("Set ACL for mount directory")
icacls $mountDir /inheritance:r
icacls $mountDir /grant:r SYSTEM:"(OI)(CI)(F)"
icacls $mountDir /grant:r *S-1-5-32-544:"(OI)(CI)(F)"
# Mount WinRE
LogMessage("Mount WinRE:")
Dism /mount-image /imagefile:$WinREFile /index:1 /mountdir:$mountDir
if ($LASTEXITCODE -eq 0)
{
# Patch WinRE
if (PatchPackage -mountDir $mountDir -packagePath $packagePath)
{
$hasUpdated = TargetfileVersionExam($mountDir)
if ($hasUpdated)
{
LogMessage("After patch, find expected version for target file")
}
else
{
LogMessage("Warning: After applying the patch, unexpected version found for the target file")
}
LogMessage("Patch succeed, unmount to commit change")
Dism /unmount-image /mountDir:$mountDir /commit
if (!($LASTEXITCODE -eq 0))
{
LogMessage("Unmount failed: " + $LASTEXITCODE)
exit 1
}
else
{
if ($hasUpdated)
{
if (IsTPMBasedProtector)
{
# Disable WinRE and re-enable it to let new WinRE be trusted by BitLocker
LogMessage("Disable WinRE")
reagentc /disable
LogMessage("Re-enable WinRE")
reagentc /enable
reagentc /info
}
# Leave a breadcrumb indicates the script has succeed
SetRegistrykeyForSuccess
}
}
}
else
{
LogMessage("Patch failed or is not applicable, discard unmount")
Dism /unmount-image /mountDir:$mountDir /discard
if (!($LASTEXITCODE -eq 0))
{
LogMessage("Unmount failed: " + $LASTEXITCODE)
exit 1
}
}
}
else
{
LogMessage("Mount failed: " + $LASTEXITCODE)
}
# Cleanup Mount directory in the end
LogMessage("Delete mount direcotry")
Remove-Item $mountDir -Recurse
More information
With the device started up into the running version of Windows installed on the device, the script will perform the following steps:
-
Mount the existing WinRE image (WINRE.WIM).
-
Update the WinRE image with the specified Safe OS Dynamic Update (Compatibility Update) package available from the Windows Update Catalog. We recommend that you use the latest Safe OS Dynamic Update available for the version of Windows installed on the device.
-
Unmount the WinRE image.
-
If the BitLocker TPM protector is present, reconfigures WinRE for BitLocker service.
Important This step is not present in most third-party scripts for applying updates to the WinRE image.
Usage
The following parameters can be passed to the script:
|
Parameter |
Description |
|---|---|
|
workDir |
<Optional> Specifies the scratch space used to patch WinRE. If not specified, the script will use the default temp folder for the device. |
|
packagePath |
<Required> Specifies the path and name of the OS-version-specific and processor architecture-specific Safe OS Dynamic update package to be used to update the WinRE image.Note This can be a local path or a remote UNC path but the Safe OS Dynamic Update must be downloaded and available for the script to use. Example: |
