CVE-2023-39848: GitHub - digininja/DVWA: Damn Vulnerable Web Application (DVWA)

DAMN VULNERABLE WEB APPLICATION

Damn Vulnerable Web Application (DVWA) is a PHP/MySQL web application that is damn vulnerable. Its main goal is to be an aid for security professionals to test their skills and tools in a legal environment, help web developers better understand the processes of securing web applications and to aid both students & teachers to learn about web application security in a controlled class room environment.

The aim of DVWA is to practice some of the most common web vulnerabilities, with various levels of difficulty, with a simple straightforward interface. Please note, there are both documented and undocumented vulnerabilities with this software. This is intentional. You are encouraged to try and discover as many issues as possible.

WARNING!

Damn Vulnerable Web Application is damn vulnerable! Do not upload it to your hosting provider’s public html folder or any Internet facing servers, as they will be compromised. It is recommended using a virtual machine (such as VirtualBox or VMware), which is set to NAT networking mode. Inside a guest machine, you can download and install XAMPP for the web server and database.

Disclaimer

We do not take responsibility for the way in which any one uses this application (DVWA). We have made the purposes of the application clear and it should not be used maliciously. We have given warnings and taken measures to prevent users from installing DVWA on to live web servers. If your web server is compromised via an installation of DVWA, it is not our responsibility, it is the responsibility of the person/s who uploaded and installed it.

License

This file is part of Damn Vulnerable Web Application (DVWA).

Damn Vulnerable Web Application (DVWA) is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

Damn Vulnerable Web Application (DVWA) is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with Damn Vulnerable Web Application (DVWA). If not, see https://www.gnu.org/licenses/.

Internationalisation

This file is available in multiple languages:

• Arabic: العربية
• Chinese: 简体中文
• French: Français
• Persian: فارسی
• Portuguese: Português
• Spanish: Español
• Turkish: Türkçe

If you would like to contribute a translation, please submit a PR. Note though, this does not mean just run it through Google Translate and send that in, those will be rejected. Submit your translated version by adding a new ‘README.xx.md’ file where xx is the two-letter code of your desired language (based on ISO 639-1).

Download

While there are various versions of DVWA around, the only supported version is the latest source from the official GitHub repository. You can either clone it from the repo:

git clone https://github.com/digininja/DVWA.git

Or download a ZIP of the files.

Installation****Installation Videos

• Installing DVWA on Kali running in VirtualBox
• Installing DVWA on Windows using XAMPP
• Installing Damn Vulnerable Web Application (DVWA) on Windows 10

Windows + XAMPP

The easiest way to install DVWA is to download and install XAMPP if you do not already have a web server setup.

XAMPP is a very easy to install Apache Distribution for Linux, Solaris, Windows and Mac OS X. The package includes the Apache web server, MySQL, PHP, Perl, a FTP server and phpMyAdmin.

This video walks you through the installation process for Windows but it should be similar for other OSs.

Docker

It is possible to run DVWA with containers.

Prerequisites: Docker and Docker Compose.

• If you are using Docker Desktop, both of these should be already installed.
• If you prefer Docker Engine on Linux, make sure to follow their installation guide.

We provide support for the latest Docker release as shown above. If you are using Linux and the Docker package that came with your package manager, it will probably work too, but support will only be best-effort.

Upgrading Docker from the package manager version to upstream requires that you uninstall the old versions as seen in their manuals for Ubuntu, Fedora and others. Your Docker data (containers, images, volumes, etc.) should not be affected, but in case you do run into a problem, make sure to tell Docker and use search engines in the mean time.

Then, to get started:

1. Run docker version and docker compose version to see if you have Docker and Docker Compose properly installed. You should be able to see the version of Docker in the output.

   For example:

   >>> docker version
   Client:
    [...]
    Version:           23.0.5
    [...]
   
   Server: Docker Desktop 4.19.0 (106363)
    Engine:
     [...]
     Version:          23.0.5
     [...]
   
   >>> docker compose version
   Docker Compose version v2.17.3
   

   If you don’t see anything or get a command not found error, follow the prerequisites to setup Docker and Docker Compose.

2. Clone or download this repository and extract (see Download).

3. Open a terminal of your choice and change its working directory to DVWA.

4. docker compose up -d.

DVWA is now available at http://localhost:4280.

Notice that for running DVWA in containers, the web server is listening on port 4280 instead of the usual port of 80. For more information on this decision, see I want to run DVWA on a different port.

Linux Packages

If you are using a Debian based Linux distribution, you will need to install the following packages (or their equivalent):

• apache2
• libapache2-mod-php
• mariadb-server
• mariadb-client
• php php-mysqli
• php-gd

I would recommend doing an update before this, just so you make sure you are going to get the latest version of everything.

apt update
apt install -y apache2 mariadb-server mariadb-client php php-mysqli php-gd libapache2-mod-php

The site will work with MySQL instead of MariaDB but we strongly recommend MariaDB as it works out of the box whereas you have to make changes to get MySQL to work correctly.

Configurations****Config File

DVWA ships with a dummy copy of its config file which you will need to copy into place and then make the appropriate changes. On Linux, assuming you are in the DVWA directory, this can be done as follows:

cp config/config.inc.php.dist config/config.inc.php

On Windows, this can be a bit harder if you are hiding file extensions, if you are unsure about this, this blog post explains more about it:

How to Make Windows Show File Extensions

Database Setup

To set up the database, simply click on the Setup DVWA button in the main menu, then click on the Create / Reset Database button. This will create / reset the database for you with some data in.

If you receive an error while trying to create your database, make sure your database credentials are correct within ./config/config.inc.php. This differs from config.inc.php.dist, which is an example file.

The variables are set to the following by default:

$_DVWA[ ‘db_server’] = '127.0.0.1’; $_DVWA[ ‘db_port’] = '3306’; $_DVWA[ ‘db_user’ ] = 'dvwa’; $_DVWA[ ‘db_password’ ] = 'p@ssw0rd’; $_DVWA[ ‘db_database’ ] = 'dvwa’;

Note, if you are using MariaDB rather than MySQL (MariaDB is default in Kali), then you can’t use the database root user, you must create a new database user. To do this, connect to the database as the root user then use the following commands:

mysql> create database dvwa; Query OK, 1 row affected (0.00 sec)

mysql> create user dvwa@localhost identified by 'p@ssw0rd’; Query OK, 0 rows affected (0.01 sec)

mysql> grant all on dvwa.* to dvwa@localhost; Query OK, 0 rows affected (0.01 sec)

mysql> flush privileges; Query OK, 0 rows affected (0.00 sec)

Disable Authentication

Some tools don’t work well with authentication so can’t be used with DVWA. To get around this, there is a config option to disable authentication checking. To do this, simply set the following in the config file:

$_DVWA[ ‘disable_authentication’ ] = true;

You will also need to set the security level to one that is appropriate to the testing you want to do:

$_DVWA[ ‘default_security_level’ ] = 'low’;

In this state, you can access all the features without needing to log in and set any cookies.

Folder Permissions

• ./hackable/uploads/ - Needs to be writeable by the web service (for File Upload).

PHP configuration

On Linux systems, likely found in /etc/php/x.x/fpm/php.ini or /etc/php/x.x/apache2/php.ini.

• To allow Remote File Inclusions (RFI):

  • allow_url_include = on [allow_url_include]
  • allow_url_fopen = on [allow_url_fopen]

• To make sure PHP shows all error messages:

  • display_errors = on [display_errors]
  • display_startup_errors = on [display_startup_errors]

Make sure you restart the php service or Apache after making the changes.

reCAPTCHA

This is only required for the “Insecure CAPTCHA” lab, if you aren’t playing with that lab, you can ignore this section.

Generated a pair of API keys from https://www.google.com/recaptcha/admin/create.

These then go in the following sections of ./config/config.inc.php:

• $_DVWA[ ‘recaptcha_public_key’ ]
• $_DVWA[ ‘recaptcha_private_key’ ]

Default Credentials

Default username = admin

Default password = password

…can easily be brute forced ;)

Login URL: http://127.0.0.1/login.php

Note: This will be different if you installed DVWA into a different directory.

Troubleshooting

These assume you are on a Debian based distro, such as Debian, Ubuntu and Kali. For other distros, follow along, but update the command where appropriate.

Containers****I want to access the logs

If you are using Docker Desktop, logs can be accessed from the graphical application. Some minor details may change with newer versions, but the access method should be the same.

Logs can also be accessed from the terminal.

1. Open a terminal and change its working directory to DVWA

2. Show the merged logs

   In case you want to export the logs to a file, e.g. dvwa.log

   docker compose logs >dvwa.log

I want to run DVWA on a different port

We don’t use port 80 by default for a few reasons:

• Some users might already be running something on port 80.
• Some users might be using a rootless container engine (like Podman), and 80 is a privileged port (< 1024). Additional configuration (e.g. setting net.ipv4.ip_unprivileged_port_start) is required, but you will have to research on your own.

You can expose DVWA on a different port by changing the port binding in the compose.yml file. For example, you can change

to

DVWA is now accessible at http://localhost:8806.

DVWA auto starts when Docker runs

The included compose.yml file automatically runs DVWA and its database when Docker starts.

To disable this, you can delete or comment out the restart: unless-stopped lines in the compose.yml file.

If you want to disable this behavior temporarily, you can run docker compose stop, or use Docker Desktop, find dvwa and click Stop. Additionally, you can delete the containers, or run docker compose down.

Log files

On Linux systems Apache generates two log files by default, access.log and error.log and on Debian based system these are usually found in /var/log/apache2/.

When submitting error reports, problems, anything like that, please include at least the last five lines from each of these files. On Debian based systems you can get these like this:

tail -n 5 /var/log/apache2/access.log /var/log/apache2/error.log

I browsed to the site and got a 404

If you are having this problem you need to understand file locations. By default, the Apache document root (the place it starts looking for web content) is /var/www/html. If you put the file hello.txt in this directory, to access it you would browse to http://localhost/hello.txt.

If you created a directory and put the file in there - /var/www/html/mydir/hello.txt - you would then need to browse to http://localhost/mydir/hello.txt.

Linux is by default case sensitive and so in the example above, if you tried to browse to any of these, you would get a 404 Not Found:

• http://localhost/MyDir/hello.txt
• http://localhost/mydir/Hello.txt
• http://localhost/MYDIR/hello.txt

How does this affect DVWA? Most people use git to checkout DVWA into /var/www/html, this gives them the directory /var/www/html/DVWA/ with all the DVWA files inside it. They then browse to http://localhost/ and get either a 404 or the default Apache welcome page. As the files are in DVWA, you must browse to http://localhost/DVWA.

The other common mistake is to browse to http://localhost/dvwa which will give a 404 because dvwa is not DVWA as far as Linux directory matching is concerned.

So after setup, if you try to visit the site and get a 404, think about where you installed the files to, where they are relative to the document root, and what the case of the directory you used is.

“Access denied” running setup

If you see the following when running the setup script it means the username or password in the config file do not match those configured on the database:

Database Error #1045: Access denied for user 'notdvwa'@'localhost' (using password: YES).

The error is telling you that you are using the username notdvwa.

The following error says you have pointed the config file at the wrong database.

SQL: Access denied for user 'dvwa'@'localhost' to database 'notdvwa'

It is saying that you are using the user dvwa and trying to connect to the database notdvwa.

The first thing to do is to double check what you think you put in the config file is what is actually there.

If it matches what you expect, the next thing to do is to check you can log in as the user on the command line. Assuming you have a database user of dvwa and a password of p@ssw0rd, run the following command:

mysql -u dvwa -pp@ssw0rd -D dvwa

Note: There is no space after the -p

If you see the following, the password is correct:

Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 14
Server version: 10.3.22-MariaDB-0ubuntu0.19.10.1 Ubuntu 19.10

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [dvwa]>

As you can connect on the command line, it is likely something wrong in the config file, double check that and then raise an issue if you still can’t get things working.

If you see the following, the username or password you are using is wrong. Repeat the Database Setup steps and make sure you use the same username and password throughout the process.

ERROR 1045 (28000): Access denied for user 'dvwa'@'localhost' (using password: YES)

If you get the following, the user credentials are correct but the user does not have access to the database. Again, repeat the setup steps and check the database name you are using.

ERROR 1044 (42000): Access denied for user 'dvwa'@'localhost' to database 'dvwa'

The final error you could get is this:

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

This is not an authentication issue but tells you that the database server is not running. Start it with the following

Unknown authentication method

With the most recent versions of MySQL, PHP can no longer talk to the database in its default configuration. If you try to run the setup script and get the following message it means you have configuration.

Database Error #2054: The server requested authentication method unknown to the client.

You have two options, the easiest is to uninstall MySQL and install MariaDB. The following is the official guide from the MariaDB project:

https://mariadb.com/resources/blog/how-to-migrate-from-mysql-to-mariadb-on-linux-in-five-steps/

Alternatively, follow these steps:

1. As root, edit the following file: /etc/mysql/mysql.conf.d/mysqld.cnf

2. Under the line [mysqld], add the following: default-authentication-plugin=mysql_native_password

3. Restart the database: sudo service mysql restart

4. Check the authentication method for your database user:

   mysql> select Host,User, plugin from mysql.user where mysql.user.User = 'dvwa’; ±----------±-----------------±----------------------+ | Host | User | plugin | ±----------±-----------------±----------------------+ | localhost | dvwa | caching_sha2_password | ±----------±-----------------±----------------------+ 1 rows in set (0.00 sec)

5. You’ll likely see caching_sha2_password. If you do, run the following command:

   mysql> ALTER USER dvwa@localhost IDENTIFIED WITH mysql_native_password BY 'p@ssw0rd’;

6. Re-running the check, you should now see mysql_native_password.

   mysql> select Host,User, plugin from mysql.user where mysql.user.User = 'dvwa’; ±----------±-----±----------------------+ | Host | User | plugin | ±----------±-----±----------------------+ | localhost | dvwa | mysql_native_password | ±----------±-----±----------------------+ 1 row in set (0.00 sec)

After all that, the setup process should now work as normal.

If you want more information see the following page: https://www.php.net/manual/en/mysqli.requirements.php.

Database Error #2002: No such file or directory.

The database server is not running. In a Debian based distro this can be done with:

Errors “MySQL server has gone away” and “Packets out of order”

There are a few reasons you could be getting these errors, but the most likely is the version of database server you are running is not compatible with the version of PHP.

This is most commonly found when you are running the latest version of MySQL as PHP and it do not get on well. Best advice, ditch MySQL and install MariaDB as this is not something we can support.

For more information, see:

https://www.ryadel.com/en/fix-mysql-server-gone-away-packets-order-similar-mysql-related-errors/

Command Injection won’t work

Apache may not have high enough privileges to run commands on the web server. If you are running DVWA under Linux make sure you are logged in as root. Under Windows log in as Administrator.

Why can’t the database connect on CentOS?

You may be running into problems with SELinux. Either disable SELinux or run this command to allow the web server to talk to the database:

setsebool -P httpd_can_network_connect_db 1

Anything Else

For the latest troubleshooting information please read both open and closed tickets in the git repo:

https://github.com/digininja/DVWA/issues

Before submitting a ticket, please make sure you are running the latest version of the code from the repo. This is not the latest release, this is the latest code from the master branch.

If raising a ticket, please submit at least the following information:

• Operating System
• The last 5 lines from the web server error log directly after whatever error you are reporting occurs
• If it is a database authentication problem, go through the steps above and screenshot each step. Submit these along with a screenshot of the section of the config file showing the database user and password.
• A full description of what is going wrong, what you expect to happen, and what you have tried to do to fix it. “login broken” is no enough for us to understand your problem and to help fix it.

Tutorials

I am going to try to put together some tutorial videos that walk through some of the vulnerabilities and show how to detect them and then how to exploit them. Here are the ones I’ve made so far:

Finding and Exploiting Reflected XSS

SQLite3 SQL Injection

Support for this is limited, before raising issues, please ensure you are prepared to work on debugging, do not simply claim "it does not work".

By default, SQLi and Blind SQLi are done against the MariaDB/MySQL server used by the site but it is possible to switch to do the SQLi testing against SQLite3 instead.

I am not going to cover how to get SQLite3 working with PHP, but it should be a simple case of installing the php-sqlite3 package and making sure it is enabled.

To make the switch, simply edit the config file and add or edit these lines:

$_DVWA["SQLI_DB"] = "sqlite";
$_DVWA["SQLITE_DB"] = "sqli.db";

By default it uses the file database/sqli.db, if you mess it up, simply copy database/sqli.db.dist over the top.

The challenges are exactly the same as for MySQL, they just run against SQLite3 instead.

👨‍💻 Contributors

Thanks for all your contributions and keeping this project updated. ❤️

If you have an idea, some kind of improvement or just simply want to collaborate, you are welcome to contribute and participate in the Project, feel free to send your PR.

Links

Project Home: https://github.com/digininja/DVWA

Created by the DVWA team