ExpressionEngine

2.11.7 User Guide

Legacy Documentation

You are using the documentation for version 2.11.7. Go here for the latest version or check here for your available upgrades to ExpressionEngine 3.

General Security Tips

There are a few basic things you can do to enhance the overall security of your web site.

Update Regularly

Keeping your installation up-to-date is the easiest way to keep your site secure. ExpressionEngine’s security measures are routinely updated to stay ahead of the ever evolving exploit landscape.

Limit User Permissions

You should only provide people with the minimum permissions they need to do what they need to do. In ExpressionEngine parlance, don’t put everyone in the Super Admin member group.

This also applies to access to your webserver. Do not provide others with FTP or SSL access unless it is absolutely necessary. Periodically review your access settings and revoke any accounts and permissions that are no longer required.

Use SSL Certificates

If possible, you should use an SSL certificate on your site and restrict all traffic to https only. This can help prevent password sniffing on insecure networks such as public wifi hotspots.

Create a Password Policy

ExpressionEngine’s password requirements are customizable. We recommend implementing a reasonable policy:

Restrict File Types

When setting up a file upload directory, forum attachments, or private message attachments you should restrict it as much as you are able. If you only expect images to be uploaded, you should only allow images. Be as strict as you can be initially, and loosen requirements on a case-by-case basis.

Remove Unused Add-ons and Applications

When an add-on or other application on the server is no longer used, we recommend removing the associated code.

Disable Uploaded Executables

ExpressionEngine prevents the upload of code to your server when using any of the native file upload tools including the custom file field in the control panel and Channel Forms, forum attachments, and private message attachments.

However, in the unlikely event that ExpressionEngine’s default safeguards are bypassed, an insecure addon is installed, outdated code is exploited, or your server is compromised in any other way, we recommend using your web-servers native security features to further lock down file upload directories.

We recommend a simple .htaccess file at the root of the directory where you’ll be allowing user uploads:

SetHandler default-handler

Note

.htaccess files only work on Apache servers that permit their usage. You should test to see if this method actually prevents files from executing by placing a simple PHP file in the same directory and test to see if it executes, like the following:

<?php echo "This should not be visible.";

This forces the Apache server to send any files in that directory, and any sub-directories, as if they were static content, completely preventing the execution of any files in that directory.

Starting with ExpressionEngine 2.10 we ship with this exact .htaccess file in the images/ directory. If you have any upload directories outside of images/, it’s highly recommended that you copy this .htaccess into that directory.

In the event that the above .htaccess doesn’t work you can also try the following .htaccess:

<FilesMatch "(?i)\.(php[s0-9]?|phtml)">
  Order Deny,Allow
  Deny from All
</FilesMatch>

Both .htaccess files will prevent PHP files from being executed in the directory which they’re located, however the former .htaccess file has the added benefit that it prevents any and all code from being executed.

In the event that neither .htaccess file works, contact your hosting company or server administrator.