Multiple Ways To Exploit HTTP Authentication

In this article, we will learn about how to configure the password protected Apache Web Server to restrict from online visitors without validation so that we can hide some essential and critical information to the un-authenticated users and how to penetrate it’s the weak configuration to breach its security and exploit it.

Table of Content

Introduction to HTTP Basic Authentication

§  Lab Set_up Requirement

Set Up Password Authentication

§  Installing the Apache Utilities Package

§  Creating the Password File

§  Configuring Access Control inside the Virtual Host Definition

§  Configuring Access Control with .htaccess Files

§  Confirm the Password Authentication

Exploiting HTTP Authentication

§  xHydra

§  Hydra

§  Ncrack

§  Mdeusa

§  Metasploit

§  Burpsuite

Introduction to HTTP Basic Authentication

In the context of a HTTP transaction, basic access authentication is a method for a HTTP user agent to provide a user name and password when making a request.

HTTP Basic authentication (BA) implementation is the simplest technique for enforcing access controls to web resources because it doesn’t require cookies, session identifiers, or login pages; rather, HTTP Basic authentication uses standard fields in the HTTP header, obviating the need for handshakes.

The BA mechanism provides no confidentiality protection for the transmitted credentials. They are merely encoded with Base64 in transit, but not encrypted or hashed in any way. HTTPS is, therefore, typically preferred used in conjunction with Basic Authentication.

For more details read from wikipedia.org

Lab Set_up Requirement

Apache Server (Ubuntu 14.04)

Penetration Testing Machine (Kali Linux)

Set Up Password Authentication

Installing the Apache Utilities Package

Let’s start with following command to install an Apache2 utility package called ‘htpasswd’. The htpasswd is used to create and update the flat-files used to store usernames and password for basic authentication of HTTP users.

sudo apt-get install apache2 apache2-utils

Creating the Password File

Now use htpasswd command to create a password file that Apache will use to authenticate users and use a hidden file “.htpasswd” in our /etc/apache2 configuration directory to store password.

sudo htpasswd -c /etc/apache2/.htpasswd raj

cat /etc/apache2/.htpasswd

gedit etc/apache2/sites-enabled/000-default.conf

Configuring Access Control inside the Virtual Host Definition

Now saved the following configuration in 000-default.conf file.

        AuthType Basic

        AuthName "Restricted Content"

        AuthUserFile /etc/apache2/.htpasswd

        Require valid-user

   

Configuring Access Control with .htaccess Files

Open the main Apache configuration file to enable password protection using .htaccess files and add following line as highlighted.

sudo gedit /etc/apache2/apache2.conf

ServerName localhost

Enable .htaccess processing by changing the AllowOverride directive "None" to "All" in the block for the /var/www directory and then save the file and restart the apache service.

    Options Indexes FollowSymLinks

    AllowOverride All

    Require all granted

Next, you need to add an .htaccess file to the directory you wish to restrict. Here, I want restrict the entire website which is could be through /var/www/html, but you can place this file in any directory where you wish to restrict access:

sudo nano /var/www/html/.htaccess

AuthType Basic

AuthName "Restricted Content"

AuthUserFile /etc/apache2/.htpasswd

Require valid-user

sudo service apache2 restart

While configuring .htaccess file we had added few options for the block directory. Let’s see what these configuration denotes.

AuthType Basic: This will set up a basic authentication for our site.

AuthName “Restricted Contents”: This will show the name of the authentication at the prompt.

AuthUserFile /etc/apache2/.htpasswd : This will show the location of the authentication file.

Require Valid-user: This will be used by one user who has confirmed their authentication who are permitted to access the website.

Confirm the Password Authentication

Try to access your restricted content in a web browser to confirm that your content is protected. I will be accessible with a username and password prompt that looks like this:

If you will try to access the website without authentication or canceled the Required Authentication page then it will displace 401 error Unauthorized Access.

If you are valid users and try to access password protected website by using valid credential, for example we had create an account with raj: 123 to access apache http service.

As you can observe that, now we are able to access the content of website.

Exploiting HTTP Authentication

xHydra

This is the graphical version to apply dictionary attack via FTP port to hack a system. For this method to work:

Open xHydra in your kali. And select Single Target option and their give the IP of your victim PC. And select HTTP in box against Protocol option and give the port number 80 against the port option.

Now, go to Passwords tab and select Username List and give the path of your text file, which contains usernames, in the box adjacent to it.

Then select Password List and give the path of your text file, which contains all the passwords, in the box adjacent to it.

After doing this, go to Start tab and click on Start button on the left.

Now, the process of dictionary attack will start. Thus, you will attain the username and password of your victim.

Hydra

Hydra is often the tool of choice. It can perform rapid dictionary attacks against more than 50 protocols, including telnet, ftp, http, https, smb, several databases, and much more

Now, we need to choose a wordlist. As with any dictionary attack, the wordlist is key. Kali has numerous wordlists built right in.

Run the following command

hydra -L user.txt -P pass.txt 192.168.0.105 http-get

-L: denotes path for username list

-P:  denotes path for password list

Once the commands are executed it will start applying the dictionary attack and so you will have the right username and password in no time. As you can observe that we had successfully grabbed the HTTP username as raj and password as 123.

Ncrack

Ncrack is a high-speed network authentication cracking tool. It was built to help companies secure their networks by proactively testing all their hosts and networking devices for poor passwords.

Run the following command

ncrack -U user.txt -P pass.txt http://192.168.0.105

Here

-U: denotes path for username list

-P:  denotes path for password list

As you can observe that we had successfully grabbed the HTTP username as raj and password as 123.

Medusa

Medusa is intended to be a speedy, massively parallel, modular, login brute-forcer. It supports many protocols: AFP, CVS, FTP, HTTP, IMAP, rlogin, SSH, Subversion, and VNC to name a few

Run the following command

medusa  -h 192.168.0.105 -U user.txt -P pass.txt -M http -f

Here

-U: denotes path for username list

-P:  denotes path for password list

As you can observe that we had successfully grabbed the HTTP username as raj and password as 123.

Metasploit

This module attempts to authenticate to an HTTP service. Open Kali terminal type msfconsole and then type: 

use auxiliary/scanner/http/http_login

msf auxiliary(scanner/http/http_login) > set user_file  user.txt

msf auxiliary(scanner/http/http_login) > set pass_file  pass.txt

msf auxiliary(scanner/http/http_login) > set rhosts 192.168.0.105

msf auxiliary(scanner/http/http_login) >  set stop_on_success

msf auxiliary(scanner/http/http_login) > exploit

Burp Suite

Now here I had just typed the random value for authentication in order to fetch the request through burp suite. So before you sent the request to server turn on the burp suite and select proxy tab then, click on the intercept is on after then send the user authentication by clicking ok

Thus the sent request will be captured by burp suite which you can see in the given below image. In the screenshot I had highlighted some value in the last line. Here it tells the type of authentication provided is basic and if you have read above theory of basic authentication I had described that it is encoded in base 64.

Now time to generate the encoded value for authentication inside the burp suite. Click on action tab select send to intruder for HTTP Fuzzing attack.

Now open intruder frame and click on the position. Configure the position where payload will be inserted into the request. The attack type determines the way in which the payload assigned to payload position. Now select “the encoded value of authentication” for payload position and click to ADD button on the left side of the frame.

The base64 encoded value of Authentication is a combination of username and password now the scenario is to generate the same encoded value of authentication with the help of user password dictionary Therefore, I have made a dictionary which contains both user password names in a text file.

In order to use dictionary as payload click on payload tab under intruder; now load your dictionary which contains user password names from payload options.

But we want to send a request in the encoded value of our payload. To encode your payload click on ADD button available under payload processing.

 A new dialog box will generate to select the rule choose an encode option from the list; now select base 64 from drag down list of URL encode key character for payload processing.

This will start a brute force attack and try to match string for user authentication. In the screenshot you can observe the status “200 OK” and length “11788”of the highlighted value is different from rest of the values. This means we can use this encoded value to bypass the user authentication, which occur from request number 5. Now check the username and password on 5th line in the dictionary. In the dictionary I found raj: 123 have matching authentication.

Or you can also use this encoded Auth value to bypass the apache http authentication page via burp suite intercepted data.

Copy the above auth value and paste replace it with intercepted authorization a shown in below and forward the request to access restricted content.

Booom!!! Here we have successfully access the content of website.

Hope you people have enjoy this article and learnt how weak configuration security can easily breach and unauthorized person can access the restrict content of your website.