Apache mod_userdir Tweak

Valid for versions 82 through the latest version

Version:

82

Last modified: 2024 September 18

Overview

This interface allows you to disable the Apache mod_userdir module’s functionality for your users.

About this module

The Apache mod_userdir module allows for visitors to access a user’s website via a URL that contains that user’s username. For example, the following URLs point to the username directory:

1
2
3

https://host.example.com/~username
https://example.net/~username  
https://192.168.0.20/~username

Most servers use the Apache mod_userdir module as a temporary URL system that allows users to view their websites. This temporary URL system functions even if the system does not possess a configured DNS or the domain does not yet point to the server.

Enable access

To enable mod_userdir access, perform the following steps:

1. Select the Enable mod_userdir Protection checkbox.
2. To enable mod_userdir functionality for specific hosts, select the appropriate Exclude Protection checkboxes.
   Important:

   This action allows all users to access content on the host via the Apache mod_userdir module. We recommend that you only enable mod_userdir functionality on the DefaultHost.
3. To only allow mod_userdir functionality for specific additional users to access these hosts, enter their usernames in the Additional Users text box.
   • Resellers can use this feature to allow their customers to access their own websites before DNS information propagates.
   • To enter multiple users, separate each account name with a space.
4. Click Save.

Example

You own the following three cPanel accounts:

• Arthur’s cPanel account (arthur) owns arthurexample.com
• Betty’s cPanel account (betty) owns bettyexample.com
• Charles’ cPanel account (charles) owns charlesexample.com

Arthur’s domain resolves, but Betty’s and Charles’ domains do not yet resolve.

To enable mod_userdir protection for the server to deny one user the ability to use another user’s bandwidth, select the Enable mod_userdir Protection checkbox.

However, if you still want to allow Betty and Charles to use Arthur’s domain to see their sites, perform the following steps:

1. Do not select the checkbox next to arthurexample.com (Arthur)
2. Enter betty charles in the Additional Users text box.
3. Click Save.

Betty and Charles can browse their sites with the following URLs:

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https://arthurexample.com/~betty
https://arthurexample.com/~charles

Security Implications

We strongly recommend that you restrict mod_userdir functionality for most of your users. mod_userdir can expose potential security issues.

• The system accounts for bandwidth per-host rather than per-user. If a user access another user’s content via mod_userdir, then the server will not record their bandwidth usage correctly. This can also potentially allow for one user to use the bandwidth of another.

When you disable mod_userdir protection for a host, we recommend that you do not exclude the entire host, but rather exclude only specific users via the Additional Users text box.

Warnings

Enable protection

Before you enable the Apache mod_userdir module, make certain that you understand the following information:

• Java servlets do not work with mod_userdir-based URLs because Tomcat requires you to add additional directives to the virtual host.
  Important:

  For more information about how to use Tomcat with cPanel & WHM, read our Tomcat via Containers documentation.
• The following PHP handlers do not allow you to use the Apache mod_userdir module.
  • PHP via CGI.
  • FastCGI.
  • PHP-FPM.
• open_basedir protection restricts PHP’s access to the home directory of the user who owns the base domain, not the home directory of the user account that a visitor accesses. If you enable open_basedir protection in WHM’s MultiPHP INI Editor interface (WHM » Home » Software » MultiPHP INI Editor), visitors cannot access some sites via the mod_userdir module.
• Websites that use the mod_rewrite or other directives in their .htaccess files will not function correctly when visitors view them through mod_userdir URLs.
• If you enable Apache’s mod_ruid2 module, then the mod_userdir module will not function correctly. For more information, read our Apache Module: ModRuid2 documentation.
  Warning:

  Under certain conditions, a user can attack another user’s account if they access a malicious script through a mod_userdir URL.

To use Apache’s mod_userdir module, perform the following actions:

• Make certain that the mod_suphp module is installed in the Apache Modules section of WHM’s EasyApache 4 interface (WHM » Home » Software » EasyApache 4).
• Select suphp for each version of PHP installed on your system in the PHP Handlers section of WHM’s MultiPHP Manager interface (WHM » Home » Software » MultiPHP Manager).

The Symlink Race Condition Protection option

The following table describes when the Symlink Race Condition Protection option blocks mod_userdir access:

Disabled protection

Before you disable mod_userdir protection, make certain that you understand the following information:

• While this WHM feature allows you to restrict mod_userdir functionality, it does not remove the module itself. Some PCI compliance scans may still detect it.
• This feature does not list IP addresses because the mod_userdir module uses virtual hosts.
  • You cannot use IP addresses to configure this feature.
  • If you do not protect the default host, you can access the server’s main IP address through the mod_userdir module in most cases.
  • If you attempt to provide protection on a dedicated IP address, the site’s contents will still display when protection is enabled. To disable this behavior, open the /etc/apache2/conf.d/includes/post_virtualhost_global.conf file with a text editor and add the following line:

    UserDir disabled