Prerequisite
Started off with IP lookup with the help of netdiscover.
Currently scanning: Finished! | Screen View: Unique Hosts
42 Captured ARP Req/Rep packets, from 4 hosts. Total size: 2520
IP At MAC Address Count Len MAC Vendor / Hostname
192.168.72.1 00:50:56:c0:00:08 33 1980 VMware, Inc.
192.168.72.2 00:50:56:f4:53:f7 3 180 VMware, Inc.
192.168.72.132 00:0c:29:ac:c1:b2 4 240 VMware, Inc.
192.168.72.254 00:50:56:e3:85:f8 2 120 VMware, Inc.
Just to make life easier I usually add an entry in my hosts file for easier access of the target machine.
echo "192.168.72.132 prime1.hub" >> /etc/hosts
hosts file entry
Okay now onto the hacking!
Reconnaissance
As always, I started off with an NMAP scan against the machine.
nmap -Pn -sV -sC -oN initial prime1.hub
Starting Nmap 7.91 ( https://nmap.org ) at 2021-02-25 00:02 EST
Nmap scan report for prime1.hub (192.168.72.132)
Host is up (0.000039s latency).
Not shown: 998 closed ports
PORT STATE SERVICE VERSION
22/tcp open ssh OpenSSH 7.2p2 Ubuntu 4ubuntu2.8 (Ubuntu Linux; protocol 2.0)
| ssh-hostkey:
| 2048 8d:c5:20:23:ab:10:ca:de:e2:fb:e5:cd:4d:2d:4d:72 (RSA)
| 256 94:9c:f8:6f:5c:f1:4c:11:95:7f:0a:2c:34:76:50:0b (ECDSA)
|_ 256 4b:f6:f1:25:b6:13:26:d4:fc:9e:b0:72:9f:f4:69:68 (ED25519)
80/tcp open http Apache httpd 2.4.18 ((Ubuntu))
|_http-server-header: Apache/2.4.18 (Ubuntu)
|_http-title: HacknPentest
MAC Address: 00:0C:29:AC:C1:B2 (VMware)
Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel
Scanning & Enumeration
Based on the scan that was run, I realized that port 80 was running a web server. This was the web app that was being served!
I then proceeded to run a Gobuster attack against the web server to enumerate all possible files and directories.
┌──(root💀nee)-[~/boxes/vulnhub/prime1]
└─# gobuster dir -u http://prime1.hub/ -w /usr/share/wordlists/dirb/common.txt -x .php,.txt,.html
===============================================================
Gobuster v3.0.1
by OJ Reeves (@TheColonial) & Christian Mehlmauer (@FireFart)
[+] Url: http://prime1.hub/
[+] Threads: 10
[+] Wordlist: /usr/share/wordlists/dirb/common.txt
[+] Status codes: 200,204,301,302,307,401,403
[+] User Agent: gobuster/3.0.1
[+] Extensions: php,txt,html
[+] Timeout: 10s
2021/02/25 00:16:11 Starting gobuster
/.hta (Status: 403)
/.hta.php (Status: 403)
/.hta.txt (Status: 403)
/.hta.html (Status: 403)
/.htaccess (Status: 403)
/.htaccess.php (Status: 403)
/.htaccess.txt (Status: 403)
/.htaccess.html (Status: 403)
/.htpasswd (Status: 403)
/.htpasswd.php (Status: 403)
/.htpasswd.txt (Status: 403)
/.htpasswd.html (Status: 403)
/dev (Status: 200)
/image.php (Status: 200)
/index.php (Status: 200)
/index.php (Status: 200)
/javascript (Status: 301)
/secret.txt (Status: 200)
/server-status (Status: 403)
/wordpress (Status: 301)
2021/02/25 00:16:13 Finished
There were a couple interesting files and directories which were uncovered from this scan.
- /Wordpress (WP installation)
- /dev (dev notes)
- index.php
- image.php
- secret.txt
Accessing prime1.hub/dev returned this note.
/dev
Accessing prime1.hub/secret.txt returned another note.
Following the github link led me to WFUZZ, the URL fuzzing tool.
====================================================================================
# ###### # # ######
# # # # #
# ##### # # #
## # # # # #
## # # # #
# # #### ######
====================================================================================
(i) USE WFUZZ TO ENUMERATE CORRECT PARAMETER FOR A PAGE.
COMMNAD = wfuzz -c -w /usr/share/wfuzz/wordlist/general/common.txt --hc 404 http://website.com/secret.php?FUZZ=something
The secret.txt note also said to "do more fuzz" on all php pages that I uncovered. Thus, I started off with the index.php page.
┌──(root💀nee)-[~/boxes/vulnhub/prime1]
└─# wfuzz -c -w /usr/share/wfuzz/wordlist/general/common.txt --hc 404 http://prime1.hub/index.php?FUZZ=something
I realized that the output length was different when the program fuzzed the file parameter. One of the earlier notes, told to look for location.txt. So I did.
Now this told me to use the param secrettier360 on another php page.
I headed to the image.php page and used the secrettier360 parameter to invoke a local file.
It worked! I was able to read the /etc/passwd file of the target machine. I also noticed that the user saket had the phrase find password.txt file in my directory. So I tried to read that file using the LFI vulnerability.
I was able to retrieve a password. However, It wasn't for SSH access. It was the password to one of the users on the wordpress install /wordpress.
I was able to login to the victor account no issues.
Exploitation
I then exploited a php file secret.php in the theme which I had write access to, to gain a reverse shell into the machine.
http://prime1.hub/wordpress/wp-admin/theme-editor.php?file=secret.php&theme=twentynineteen
I then overwrote this file with a php reverse shell that I had and hit update.
Lastly to get the reverse shell, I simply triggered the php file to run and caught the shell with my netcat listener.
http://prime1.hub/wordpress/wp-content/themes/twentynineteen/secret.php
Privilege Escalation
I threw linpeas at the system which revealed that the kernel version was outdated and possibly exploitable.
I then looked on Searchsploit for an exploit which fit this particular system, found a suitable exploit, compiled it and ran it! This was the exploit I used for this particular kernel to perform local privilege escalation.
┌──(root💀nee)-[~/boxes/vulnhub/prime1]
└─# searchsploit ubuntu
Linux Kernel < 4.13.9 (Ubuntu 16.04 / Fedora 27) - Local Privilege Escalation | linux/local
Hosting the exploit file on a local webserver
Grabbing the exploit, compiling and running it
gcc filename.c -o output
ROOTY!
