How To Install and Secure phpMyAdmin on Debian 9

Introduction

While many users need the functionality of a database management system like MariaDB, they may not feel comfortable interacting with the system solely from the MariaDB prompt.

phpMyAdmin was created so that users can interact with MariaDB through a web interface. In this guide, we’ll discuss how to install and secure phpMyAdmin so that you can safely use it to manage your databases on a Debian 9 system.

Prerequisites

Before you get started with this guide, you need to have some basic steps completed.

First, we’ll assume that your server has a non-root user with sudo privileges, as well as a firewall configured with ufw, as described in the initial server setup guide for Debian 9.

We’re also going to assume that you’ve completed a LAMP (Linux, Apache, MariaDB, and PHP) installation on your Debian 9 server. If you’ve not yet done this, follow our guide on installing a LAMP stack on Debian 9 to set this up.

Finally, there are important security considerations when using software like phpMyAdmin, since it:

• Communicates directly with your MariaDB installation
• Handles authentication using MariaDB credentials
• Executes and returns results for arbitrary SQL queries

For these reasons, and because it is a widely-deployed PHP application which is frequently targeted for attack, you should never run phpMyAdmin on remote systems over a plain HTTP connection. If you do not have an existing domain configured with an SSL/TLS certificate, you can follow this guide on securing Apache with Let’s Encrypt on Debian 9. This will require you to register a domain name, create DNS records for your server, and set up an Apache Virtual Host.

Once you are finished with these steps, you’re ready to get started with this guide.

Step 1 — Installing phpMyAdmin

To get started, we will install phpMyAdmin from the default Debian repositories.

This is done by updating your server’s package index and then using the apt packaging system to pull down the files and install them on your system:

sudo apt update
sudo apt install phpmyadmin php-mbstring php-gettext

This will ask you a few questions in order to configure your installation correctly.

• For the server selection, choose apache2
• Select Yes when asked whether to use dbconfig-common to set up the database
• You will then be asked to choose and confirm a MySQL application password for phpMyAdmin

The installation process adds the phpMyAdmin Apache configuration file into the /etc/apache2/conf-enabled/ directory, where it is read automatically. The only thing you need to do is explicitly enable the mbstring PHP extension which is used to manage non-ASCII strings and convert strings to different encodings. Do this by typing:

sudo phpenmod mbstring

Afterwards, restart Apache for your changes to be recognized:

sudo systemctl restart apache2

phpMyAdmin is now installed and configured. However, before you can log in and begin managing your MariaDB databases, you will need to ensure that your MariaDB users have the privileges required for interacting with the program.

Step 2 — Adjusting User Authentication and Privileges

When you installed phpMyAdmin onto your server, it automatically created a database user called phpmyadmin which performs certain underlying processes for the program. Rather than logging in as this user with the administrative password you set during installation, it’s recommended that you log in using a different account.

In new installs on Debian systems, the root MariaDB user is set to authenticate using the unix_socket plugin by default rather than with a password. This allows for some greater security and usability in many cases, but it can also complicate things when you need to allow an external program (e.g., phpMyAdmin) administrative rights through this user. Because the server uses the root account for tasks like log rotation and starting and stopping the server, it is best not to change the root account’s authentication details. Since phpMyAdmin requires users to authenticate with a password, you will need to create a new MariaDB account in order to access the interface.

If you followed the prerequisite tutorial on installing a LAMP stack and created a MariaDB user account as described in Step 2, you can just log in to phpMyAdmin under that account using the password you created when you set it up by visiting this link:

https://your_domain_or_IP/phpmyadmin

If you haven’t created a MariaDB user, or if you have but you’d like to create another user just for the purpose of managing databases through phpMyAdmin, continue on with this section to learn how to set one up.

Begin by opening up the MariaDB shell:

sudo mariadb

mariadb -u user -p

From there, create a new user and give it a strong password:

CREATE USER 'sammy'@'localhost' IDENTIFIED BY 'password';

Then, grant your new user appropriate privileges. For example, you could grant the user privileges to all tables within the database, as well as the power to add, change, and remove user privileges, with this command:

GRANT ALL PRIVILEGES ON *.* TO 'sammy'@'localhost' WITH GRANT OPTION;

Following that, exit the MariaDB shell:

exit

You can now access the web interface by visiting your server’s domain name or public IP address, followed by /phpmyadmin:

https://your_domain_or_IP/phpmyadmin

Log in to the interface with the username and password you configured.

When you log in, you’ll see the user interface, which will look something like this:

Now that you’re able to connect and interact with phpMyAdmin, all that’s left to do is harden your system’s security to protect it from attackers.

Step 3 — Securing Your phpMyAdmin Instance

Because of its ubiquity, phpMyAdmin is a popular target for attackers, and you should take extra care to prevent unauthorized access. One of the easiest ways of doing this is to place a gateway in front of the entire application by using Apache’s built-in .htaccess authentication and authorization functionalities.

To do this, you must first enable the use of .htaccess file overrides by editing your Apache configuration file.

Edit the linked file that has been placed in your Apache configuration directory:

sudo nano /etc/apache2/conf-available/phpmyadmin.conf

Add an AllowOverride All directive within the <Directory /usr/share/phpmyadmin> section of the configuration file, like this:

<Directory /usr/share/phpmyadmin>
    Options FollowSymLinks
    DirectoryIndex index.php
    AllowOverride All
    . . .

When you have added this line, save and close the file.

To implement the changes you made, restart Apache:

sudo systemctl restart apache2

Now that you have enabled .htaccess use for your application, you need to create one to actually implement some security.

In order for this to be successful, the file must be created within the application directory. You can create the necessary file and open it in your text editor with root privileges by typing:

sudo nano /usr/share/phpmyadmin/.htaccess

Within this file, enter the following information:

AuthType Basic
AuthName "Restricted Files"
AuthUserFile /etc/phpmyadmin/.htpasswd
Require valid-user

Here is what each of these lines mean:

• AuthType Basic: This line specifies the authentication type that you are implementing. This type will implement password authentication using a password file.
• AuthName: This sets the message for the authentication dialog box. You should keep this generic so that unauthorized users won’t gain any information about what is being protected.
• AuthUserFile: This sets the location of the password file that will be used for authentication. This should be outside of the directories that are being served. We will create this file shortly.
• Require valid-user: This specifies that only authenticated users should be given access to this resource. This is what actually stops unauthorized users from entering.

When you are finished, save and close the file.

The location that you selected for your password file was /etc/phpmyadmin/.htpasswd. You can now create this file and pass it an initial user with the htpasswd utility:

sudo htpasswd -c /etc/phpmyadmin/.htpasswd username

You will be prompted to select and confirm a password for the user you are creating. Afterwards, the file is created with the hashed password that you entered.

If you want to enter an additional user, you need to do so without the -c flag, like this:

sudo htpasswd /etc/phpmyadmin/.htpasswd additionaluser

Now, when you access your phpMyAdmin subdirectory, you will be prompted for the additional account name and password that you just configured:

https://domain_name_or_IP/phpmyadmin

After entering the Apache authentication, you’ll be taken to the regular phpMyAdmin authentication page to enter your MariaDB credentials. This setup adds an additional layer of security, which is desirable since phpMyAdmin has suffered from vulnerabilities in the past.

Conclusion

You should now have phpMyAdmin configured and ready to use on your Debian 9 server. Using this interface, you can easily create databases, users, tables, etc., and perform the usual operations like deleting and modifying structures and data.