Allow fallback to SSL 3.0 (Internet Explorer)

ComputerNative Intune settingAdvanced_EnableSSL3Fallback

Supported on At least Internet Explorer 7.0

25H2 · 1.0

What it does

This policy setting allows you to block an insecure fallback to SSL 3.0. When this policy is enabled, Internet Explorer will attempt to connect to sites using SSL 3.0 or below when TLS 1.0 or greater fails. We recommend that you do not allow insecure fallback in order to prevent a man-in-the-middle attack. This policy does not affect which security protocols are enabled. If you disable this policy, system defaults will be used.

What it writes

Hive: HKEY_LOCAL_MACHINE
Registry key: Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings

In Intune

Native Intune setting: Yes — Policy CSP

./Device/Vendor/MSFT/Policy/Config/InternetExplorer/AllowFallbackToSSL3InternetExplorer on Microsoft LearnADMX-backed: Windows ships this template, so it is set with the template's own values, without an import.Windows builds listed: 10.0.16299.

From Microsoft's Policy CSP DDF files (DDF v2 Files, February 2026), read 18 Oct 2026.

Security baselines

Microsoft's Windows 11 v26H2 Security Baseline v2 sets this to Enabled, in its GPO “MSFT Internet Explorer 11 - Computer”.

Allow insecure fallback for: Set to “No Sites” (0).

Read from the registry.pol files in the baselines' GPO backups, downloaded from Microsoft's Security Compliance Toolkit. All baselines

Options

Option	Type	Registry value	Allowed values
Allow insecure fallback forDefault: No Sites	Drop-down list	`EnableSSL3Fallback`	No Sites`0` Non-Protected Mode Sites`1` All Sites`3`

Configure and deploy

Choose a state and the option values; the output below is generated from the template for exactly that.

Enabled · Computer · template defaults

Registry file (.reg)

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings]
"EnableSSL3Fallback"=dword:00000000

PowerShell

$ErrorActionPreference = 'Stop'

function Set-RegistryValue {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name,
        [Parameter(Mandatory = $true)][string] $PropertyType,
        [Parameter(Mandatory = $true)][object] $Value
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        New-Item -Path $Path -Force | Out-Null
    }

    New-ItemProperty -LiteralPath $Path -Name $Name -PropertyType $PropertyType -Value $Value -Force | Out-Null
}

function Remove-RegistryValue {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name
    )

    if (Test-Path -LiteralPath $Path) {
        Remove-ItemProperty -LiteralPath $Path -Name $Name -Force -ErrorAction SilentlyContinue
    }
}

function Clear-RegistryKeyValues {
    param(
        [Parameter(Mandatory = $true)][string] $Path
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        return
    }

    foreach ($propertyName in (Get-Item -LiteralPath $Path).Property) {
        Remove-ItemProperty -LiteralPath $Path -Name $propertyName -Force -ErrorAction SilentlyContinue
    }
}

# Policy: Allow fallback to SSL 3.0 (Internet Explorer)
# Name: Advanced_EnableSSL3Fallback
# Scope: Machine
# State: Enabled
# Source: inetres.admx

Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings' -Name 'EnableSSL3Fallback' -PropertyType 'DWord' -Value 0

These deployment candidates come from the ADMX template; they are separate from the native CSP mapping above.

The OMA-URI is an inferred ADMX-backed Policy CSP candidate derived from the source ADMX file name and policy name.
Some Microsoft policies use built-in Policy CSP pages whose area names don't match the ADMX file name, so verify the candidate against Microsoft Learn before deployment.

ADMX profile candidate (OMA-URI)

./Device/Vendor/MSFT/Policy/Config/ADMX_inetres/Advanced_EnableSSL3Fallback

ADMX SyncML candidate

<SyncML xmlns="SYNCML:SYNCML1.2">
  <SyncBody>
    <Replace>
      <CmdID>1</CmdID>
      <Item>
        <Meta>
          <Format>chr</Format>
          <Type>text/plain</Type>
        </Meta>
        <Target>
          <LocURI>./Device/Vendor/MSFT/Policy/Config/ADMX_inetres/Advanced_EnableSSL3Fallback</LocURI>
        </Target>
        <Data>&lt;enabled/&gt;
&lt;data id="Advanced_EnableSSL3FallbackOptions" value="0"/&gt;</Data>
      </Item>
    </Replace>
    <Final/>
  </SyncBody>
</SyncML>

Intune remediation scripts

Detection

$ErrorActionPreference = 'Stop'
$reasons = [System.Collections.Generic.List[string]]::new()

function Test-RegistryValueExists {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        return $false
    }

    return $null -ne (Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction SilentlyContinue)
}

function Test-RegistryValueEquals {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name,
        [Parameter(Mandatory = $true)][string] $Kind,
        [Parameter(Mandatory = $true)][object] $Expected
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        return $false
    }

    $valueObject = Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction SilentlyContinue
    if ($null -eq $valueObject) {
        return $false
    }

    $actual = $valueObject.$Name
    switch ($Kind) {
        'String' { return [string]$actual -ceq [string]$Expected }
        'ExpandString' { return [string]$actual -ceq [string]$Expected }
        'DWord' { return [uint32]$actual -eq [uint32]$Expected }
        'QWord' { return [uint64]$actual -eq [uint64]$Expected }
        'MultiString' {
            $actualArray = @($actual)
            $expectedArray = @($Expected)
            if ($actualArray.Count -ne $expectedArray.Count) { return $false }
            for ($index = 0; $index -lt $actualArray.Count; $index++) {
                if ([string]$actualArray[$index] -cne [string]$expectedArray[$index]) { return $false }
            }
            return $true
        }
        'Binary' {
            $actualArray = [byte[]]$actual
            $expectedArray = [byte[]]$Expected
            if ($actualArray.Length -ne $expectedArray.Length) { return $false }
            for ($index = 0; $index -lt $actualArray.Length; $index++) {
                if ($actualArray[$index] -ne $expectedArray[$index]) { return $false }
            }
            return $true
        }
        default { return [string]$actual -ceq [string]$Expected }
    }
}

# Policy: Allow fallback to SSL 3.0 (Internet Explorer)
# Name: Advanced_EnableSSL3Fallback
# Scope: Machine
# State: Enabled
# Source: inetres.admx

$isMatch = Test-RegistryValueEquals -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings' -Name 'EnableSSL3Fallback' -Kind 'DWord' -Expected 0
if (-not $isMatch) {
    $reasons.Add('Value mismatch: HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings\EnableSSL3Fallback') | Out-Null
}

if ($reasons.Count -eq 0) {
    Write-Output 'Compliant'
    exit 0
}

$reasons | ForEach-Object { Write-Output $_ }
exit 1

Remediation

$ErrorActionPreference = 'Stop'

function Set-RegistryValue {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name,
        [Parameter(Mandatory = $true)][string] $PropertyType,
        [Parameter(Mandatory = $true)][object] $Value
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        New-Item -Path $Path -Force | Out-Null
    }

    New-ItemProperty -LiteralPath $Path -Name $Name -PropertyType $PropertyType -Value $Value -Force | Out-Null
}

function Remove-RegistryValue {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name
    )

    if (Test-Path -LiteralPath $Path) {
        Remove-ItemProperty -LiteralPath $Path -Name $Name -Force -ErrorAction SilentlyContinue
    }
}

function Clear-RegistryKeyValues {
    param(
        [Parameter(Mandatory = $true)][string] $Path
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        return
    }

    foreach ($propertyName in (Get-Item -LiteralPath $Path).Property) {
        Remove-ItemProperty -LiteralPath $Path -Name $propertyName -Force -ErrorAction SilentlyContinue
    }
}

# Policy: Allow fallback to SSL 3.0 (Internet Explorer)
# Name: Advanced_EnableSSL3Fallback
# Scope: Machine
# State: Enabled
# Source: inetres.admx

Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings' -Name 'EnableSSL3Fallback' -PropertyType 'DWord' -Value 0

History 5 retained releases

22H2 · 1.015 Jul 2024
- Already present in the first release ChangeIntel keeps.

4 later releases left it unchanged.

Template

Internal name: Advanced_EnableSSL3Fallback
Namespace: Microsoft.Policies.InternetExplorer
Template file: inetres.admx
Release: Windows 11 25H2 · 1.0 · file set de4e49983ebd651f…

Definition, editor controls and support

Definition

<policy class="Machine" displayName="$(string.Advanced_EnableSSL3Fallback)" explainText="$(string.Advanced_ExplainEnableSSL3Fallback)" key="Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings" name="Advanced_EnableSSL3Fallback" presentation="$(presentation.Advanced_EnableSSL3Fallback)" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="Microsoft.Policies.InternetExplorer:SecurityFeatures" />
      <supportedOn ref="Microsoft.Policies.InternetExplorer:SUPPORTED_IE7" />
      <elements>
        
        <enum id="Advanced_EnableSSL3FallbackOptions" required="false" valueName="EnableSSL3Fallback">
          <item displayName="$(string.Advanced_FallbackNone)">
            <value>
              <decimal value="0" />
            </value>
          </item>
          <item displayName="$(string.Advanced_FallbackNonProtected)">
            <value>
              <decimal value="1" />
            </value>
          </item>
          <item displayName="$(string.Advanced_FallbackAll)">
            <value>
              <decimal value="3" />
            </value>
          </item>
        </enum>
      </elements>
    </policy>

Editor controls

<presentation id="Advanced_EnableSSL3Fallback" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
        <dropdownList defaultItem="0" noSort="true" refId="Advanced_EnableSSL3FallbackOptions">Allow insecure fallback for:</dropdownList>
      </presentation>

Supported platforms and category

Microsoft.Policies.InternetExplorer:category:InternetExplorer
<category displayName="$(string.InternetExplorer)" explainText="$(string.IE_ExplainCat)" name="InternetExplorer" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="Microsoft.Policies.Windows:WindowsComponents" />
    </category>
Microsoft.Policies.InternetExplorer:category:SecurityFeatures
<category displayName="$(string.SecurityFeatures)" explainText="$(string.IESF_ExplainSecurityFeaturesCategory)" name="SecurityFeatures" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="Microsoft.Policies.InternetExplorer:InternetExplorer" />
    </category>
Microsoft.Policies.InternetExplorer:definition:SUPPORTED_IE7
<definition displayName="$(string.SUPPORTED_IE7)" name="SUPPORTED_IE7" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
        <or>
          <range minVersionIndex="7" ref="Microsoft.Policies.Products:InternetExplorer" />
        </or>
      </definition>
Microsoft.Policies.Products:product:InternetExplorer
sha256:f287ee590cbba46b7a95511866303967b9370c7c7d81185659d675ca19b05d72
Microsoft.Policies.Windows:category:WindowsComponents
<category displayName="$(string.WindowsComponents)" explainText="$(string.WindowsComponents_Help)" name="WindowsComponents" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
Microsoft.Policies.InternetExplorer:category:InternetExplorer
<category displayName="$(string.InternetExplorer)" explainText="$(string.IE_ExplainCat)" name="InternetExplorer" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="Microsoft.Policies.Windows:WindowsComponents" />
    </category>
<strings><string id="Microsoft.Policies.InternetExplorer:IE_ExplainCat">Contains settings to configure Internet Explorer</string><string id="Microsoft.Policies.InternetExplorer:InternetExplorer">Internet Explorer</string></strings>
Microsoft.Policies.InternetExplorer:category:SecurityFeatures
<category displayName="$(string.SecurityFeatures)" explainText="$(string.IESF_ExplainSecurityFeaturesCategory)" name="SecurityFeatures" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="Microsoft.Policies.InternetExplorer:InternetExplorer" />
    </category>
<strings><string id="Microsoft.Policies.InternetExplorer:IESF_ExplainSecurityFeaturesCategory">Contains settings to enable or disable security features for Internet Explorer, File Explorer and other applications.</string><string id="Microsoft.Policies.InternetExplorer:SecurityFeatures">Security Features</string></strings>
Microsoft.Policies.InternetExplorer:definition:SUPPORTED_IE7
<definition displayName="$(string.SUPPORTED_IE7)" name="SUPPORTED_IE7" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
        <or>
          <range minVersionIndex="7" ref="Microsoft.Policies.Products:InternetExplorer" />
        </or>
      </definition>
<strings><string id="Microsoft.Policies.InternetExplorer:SUPPORTED_IE7">At least Internet Explorer 7.0</string></strings>
Microsoft.Policies.Products:product:InternetExplorer
<product displayName="$(string.InternetExplorer)" name="InternetExplorer" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
        <majorVersion displayName="$(string.InternetExplorer30)" name="InternetExplorer30" versionIndex="3" />
        <majorVersion displayName="$(string.InternetExplorer40)" name="InternetExplorer40" versionIndex="4" />
        <majorVersion displayName="$(string.InternetExplorer50)" name="InternetExplorer50" versionIndex="5" />
        <majorVersion displayName="$(string.InternetExplorer60)" name="InternetExplorer60" versionIndex="6" />
        <majorVersion displayName="$(string.InternetExplorer70)" name="InternetExplorer70" versionIndex="7" />
        <majorVersion displayName="$(string.InternetExplorer80)" name="InternetExplorer80" versionIndex="8" />
        <majorVersion displayName="$(string.InternetExplorer90)" name="InternetExplorer90" versionIndex="9" />
        <majorVersion displayName="$(string.InternetExplorer100)" name="InternetExplorer100" versionIndex="10" />
        <majorVersion displayName="$(string.InternetExplorer110)" name="InternetExplorer110" versionIndex="11" />
      </product>
<strings><string id="Microsoft.Policies.Products:InternetExplorer">Internet Explorer</string><string id="Microsoft.Policies.Products:InternetExplorer100">Internet Explorer 10</string><string id="Microsoft.Policies.Products:InternetExplorer110">Internet Explorer 11</string><string id="Microsoft.Policies.Products:InternetExplorer30">Internet Explorer 3</string><string id="Microsoft.Policies.Products:InternetExplorer40">Internet Explorer 4</string><string id="Microsoft.Policies.Products:InternetExplorer50">Internet Explorer 5</string><string id="Microsoft.Policies.Products:InternetExplorer60">Internet Explorer 6</string><string id="Microsoft.Policies.Products:InternetExplorer70">Internet Explorer 7</string><string id="Microsoft.Policies.Products:InternetExplorer80">Internet Explorer 8</string><string id="Microsoft.Policies.Products:InternetExplorer90">Internet Explorer 9</string></strings>
Microsoft.Policies.Windows:category:WindowsComponents
<category displayName="$(string.WindowsComponents)" explainText="$(string.WindowsComponents_Help)" name="WindowsComponents" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
<strings><string id="Microsoft.Policies.Windows:WindowsComponents">Windows Components</string><string id="Microsoft.Policies.Windows:WindowsComponents_Help">Contains settings for operating system components.</string></strings>