Default FTP Command Filtering Settings <commandFiltering>

The <commandFiltering> element specifies a collection of FTP commands that the FTP service will allow or deny. The <commandFiltering> element contains a collection of <add> statements that individually specify whether to allow or deny a specific FTP command.

The collection in the <commandFiltering> element is related to the <requestFiltering> settings; however, while request filtering applies for files and directories and can be configured per URL, the settings under the <commandFiltering> element apply the protocol-level of processing and can only be configured at the site level.

Additional attributes for the <commandFiltering> element are maxCommandLine and allowUnlisted. Respectively, these configure the maximum command line length and whether to allow unlisted commands.

With Windows 7 and Windows Server 2008 R2, the FTP 7.5 service ships as a feature for IIS 7.5, so downloading the FTP service is no longer necessary.

To support FTP publishing for your Web server, you must install the FTP service. To do so, use the following steps.

1. On the taskbar, click Server Manager.

2. In Server Manager, click the Manage menu, and then click Add Roles and Features.

3. In the Add Roles and Features wizard, click Next. Select the installation type and click Next. Select the destination server and click Next.

4. On the Server Roles page, expand Web Server (IIS), and then select FTP Server.

   Note

   To support ASP.Membership authentication or IIS Manager authentication for the FTP service, you will need to select FTP Extensibility, in addition to FTP Service.
   .

5. Click Next, and then on the Select features page, click Next again.

6. On the Confirm installation selections page, click Install.

7. On the Results page, click Close.

1. On the Start screen, move the pointer all the way to the lower left corner, right-click the Start button, and then click Control Panel.

2. In Control Panel, click Programs and Features, and then click Turn Windows features on or off.

3. Expand Internet Information Services, and then select FTP Server.

   Note

   To support ASP.Membership authentication or IIS Manager authentication for the FTP service, you will also need to select FTP Extensibility.
   

4. Click OK.

5. Click Close.

1. On the taskbar, click Start, point to Administrative Tools, and then click Server Manager.

2. In the Server Manager hierarchy pane, expand Roles, and then click Web Server (IIS).

3. In the Web Server (IIS) pane, scroll to the Role Services section, and then click Add Role Services.

4. On the Select Role Services page of the Add Role Services Wizard, expand FTP Server.

5. Select FTP Service.

   Note

   To support ASP.Membership authentication or IIS Manager authentication for the FTP service, you will also need to select FTP Extensibility.
   

6. Click Next.

7. On the Confirm Installation Selections page, click Install.

8. On the Results page, click Close.

1. On the taskbar, click Start, and then click Control Panel.

2. In Control Panel, click Programs and Features, and then click Turn Windows Features on or off.

3. Expand Internet Information Services, and then FTP Server.

4. Select FTP Service.

   Note

   To support ASP.Membership authentication or IIS Manager authentication for the FTP service, you will also need to select FTP Extensibility.
   

5. Click OK.

1. Download the installation package from the following URL:

   • https://www.iis.net/expand/FTP

2. Follow the instructions in the following walkthrough to install the FTP service:

   • Installing and Troubleshooting FTP 7

1. Open Internet Information Services (IIS) Manager:

   • If you are using Windows Server 2012 or Windows Server 2012 R2:

     • On the taskbar, click Server Manager, click Tools, and then click Internet Information Services (IIS) Manager.

   • If you are using Windows 8 or Windows 8.1:

     • Hold down the Windows key, press the letter X, and then click Control Panel.
     • Click Administrative Tools, and then double-click Internet Information Services (IIS) Manager.

   • If you are using Windows Server 2008 or Windows Server 2008 R2:

     • On the taskbar, click Start, point to Administrative Tools, and then click Internet Information Services (IIS) Manager.

   • If you are using Windows Vista or Windows 7:

     • On the taskbar, click Start, and then click Control Panel.
     • Double-click Administrative Tools, and then double-click Internet Information Services (IIS) Manager.

2. In the Connections pane, expand the server name, expand the Sites node, and then click the name of the site.

3. In the site's Home pane, double-click the FTP Request Filtering feature.

4. Click the Commands tab.
   

5. Click Deny Command... in the Actions pane.

6. Enter an FTP command to deny. For example:

   • Many FTP clients do not send or need the SYST command, which may reveal information about your operating system.
   • FTP 7.0 and FTP 7.5 do not implement the ACCT command, so it may be blocked safely.

7. Click OK.
   

The <commandFiltering> element is configured at the site level.

The following configuration sample displays an example <siteDefaults> element for a server that disables the SYST command by default. The SYST command returns the host operating system of the FTP server.

<siteDefaults>
   <ftpServer>
      <security>
         <commandFiltering>
            <add command="SYST" allowed="false" />
         </commandFiltering>
      </security>
   </ftpServer>
</siteDefaults>

The following code samples demonstrate how to configure the FTP service to deny the SYST command by default. The SYST command returns the host operating system of the FTP server.

appcmd.exe set config -section:system.applicationHost/sites /+"siteDefaults.ftpServer.security.commandFiltering.[command='SYST',allowed='False']" /commit:apphost

using System;
using System.Text;
using Microsoft.Web.Administration;

internal static class Sample
{
   private static void Main()
   {
      using (ServerManager serverManager = new ServerManager())
      {
         Configuration config = serverManager.GetApplicationHostConfiguration();
         ConfigurationSection sitesSection = config.GetSection("system.applicationHost/sites");
         ConfigurationElement siteDefaultsElement = sitesSection.GetChildElement("siteDefaults");
         ConfigurationElement ftpServerElement = siteDefaultsElement.GetChildElement("ftpServer");

         ConfigurationElement securityElement = ftpServerElement.GetChildElement("security");
         ConfigurationElement commandFilteringElement = securityElement.GetChildElement("commandFiltering");
         ConfigurationElementCollection commandFilteringCollection = commandFilteringElement.GetCollection();
         ConfigurationElement addElement = commandFilteringCollection.CreateElement("add");
            addElement["command"] = @"SYST";
            addElement["allowed"] = false;
            commandFilteringCollection.Add(addElement);

         serverManager.CommitChanges();
      }
   }
}

Imports System
Imports System.Text
Imports Microsoft.Web.Administration

Module Sample
   Sub Main()
      Dim serverManager As ServerManager = New ServerManager
      Dim config As Configuration = serverManager.GetApplicationHostConfiguration
      Dim sitesSection As ConfigurationSection = config.GetSection("system.applicationHost/sites")
      Dim siteDefaultsElement As ConfigurationElement = sitesSection.GetChildElement("siteDefaults")
      Dim ftpServerElement As ConfigurationElement = siteDefaultsElement.GetChildElement("ftpServer")

      Dim securityElement As ConfigurationElement = ftpServerElement.GetChildElement("security")
      Dim commandFilteringElement As ConfigurationElement = securityElement.GetChildElement("commandFiltering")
      Dim commandFilteringCollection As ConfigurationElementCollection = commandFilteringElement.GetCollection
      Dim addElement As ConfigurationElement = commandFilteringCollection.CreateElement("add")
         addElement("command") = "SYST"
         addElement("allowed") = False
         commandFilteringCollection.Add(addElement)
 
      serverManager.CommitChanges()
   End Sub

End Module

var adminManager = new ActiveXObject('Microsoft.ApplicationHost.WritableAdminManager');
adminManager.CommitPath = "MACHINE/WEBROOT/APPHOST";

var sitesSection = adminManager.GetAdminSection("system.applicationHost/sites", "MACHINE/WEBROOT/APPHOST");
var siteDefaultsElement = sitesSection.ChildElements.Item("siteDefaults");
var ftpServerElement = siteDefaultsElement.ChildElements.Item("ftpServer");

var securityElement = ftpServerElement.ChildElements.Item("security");
var commandFilteringElement = securityElement.ChildElements.Item("commandFiltering");
var commandFilteringCollection = commandFilteringElement.Collection;
var addElement = commandFilteringCollection.CreateNewElement("add");
   addElement.Properties.Item("command").Value = "SYST";
   addElement.Properties.Item("allowed").Value = false;
   commandFilteringCollection.AddElement(addElement);

adminManager.CommitChanges();

Set adminManager = createObject("Microsoft.ApplicationHost.WritableAdminManager")
adminManager.CommitPath = "MACHINE/WEBROOT/APPHOST"
Set sitesSection = adminManager.GetAdminSection("system.applicationHost/sites", "MACHINE/WEBROOT/APPHOST")
Set siteDefaultsElement = sitesSection.ChildElements.Item("siteDefaults")
Set ftpServerElement = siteDefaultsElement.ChildElements.Item("ftpServer")

Set securityElement = ftpServerElement.ChildElements.Item("security")
Set commandFilteringElement = securityElement.ChildElements.Item("commandFiltering")
Set commandFilteringCollection = commandFilteringElement.Collection
Set addElement = commandFilteringCollection.CreateNewElement("add")
   addElement.Properties.Item("command").Value = "SYST"
   addElement.Properties.Item("allowed").Value = False
   commandFilteringCollection.AddElement(addElement)

adminManager.CommitChanges()