private/functions/Set-UseUnsafeHeaderParsing.ps1

function Set-UseUnsafeHeaderParsing {
    param(
        [Parameter(Mandatory,ParameterSetName='Enable')]
        [switch]$Enable,

        [Parameter(Mandatory,ParameterSetName='Disable')]
        [switch]$Disable
    )

    $ShouldEnable = $PSCmdlet.ParameterSetName -eq 'Enable'

    $netAssembly = [Reflection.Assembly]::GetAssembly([System.Net.Configuration.SettingsSection])

    if($netAssembly) {
        $bindingFlags = [Reflection.BindingFlags] 'Static,GetProperty,NonPublic'
        $settingsType = $netAssembly.GetType('System.Net.Configuration.SettingsSectionInternal')

        $instance = $settingsType.InvokeMember('Section', $bindingFlags, $null, $null, @())

        if($instance) {
            $bindingFlags = 'NonPublic','Instance'
            $useUnsafeHeaderParsingField = $settingsType.GetField('useUnsafeHeaderParsing', $bindingFlags)

            if($useUnsafeHeaderParsingField) {
              $useUnsafeHeaderParsingField.SetValue($instance, $ShouldEnable)
            }
        }
    }
}