@TryHackMe – Pickle Rick CTF

Another day, another challenge.

Today’s blog post I will be solving the Pickle Rick CTF on TryHackMe.com. Click HERE to be redirected to the challenge.

After hitting the deploy button we now have our IP address.

pickle_ip_address

We see that this challenge is focused on finding vulnerabilities in a web server.

Let’s run nmap, nikto, and dirbuster to see what we find…

pickle_nmap

Executing nmap, we see that there are two port open – 22 (ssh), and 80 (http).

Moving on to nikto…

pickle_nikto

Running nikto we see that there is an login php file which is interested.

Finally, let’s look at dirbuster.

pickle_dirb

With dirbuster we have an access directory, as well as an index.html, and robots.txt file (both returning a 200 which is good). We also have a server-status which is returning a forbidden http code of 403.

We’ve done basic enumeration let’s move to the web app and see if we can find more clues.

Let’s answer the first question.

pickle_first_ingredient_question

Navigating to the IP address in a browser we see the following.pickle_landing_page

Nothing really stands out, except for the burping :-). Let’s view the source code and see what we find.pickle_source_code

Viewing the source code (Right click on page, select view source code) we see at the bottom there’s a username. Let’s see if we can find a password. Maybe our dirbuster results will come in handy…pickle_robots

Going back to our results in dirb we notice there’s a robots.txt file. Going to this file, we see the above. Hmm, this is a strange robots.txt file. Maybe this could be the password, let’s see if it works.pickle_login

In our nikto results, we had a login page. Navigating to that page and entering our username from the index.html page, and a password from the robots.txt page we get the following.pickle_portal

Success! We’re in the application.

Let’s run the ls (listing) command with the options of all and long listing and see what we have.

pickle_listing

pickle_listing_directory

Opening the Sup3rS3cretPickl3Ingred.txt file we have the first ingredient below.pickle_first_ingredient

Also notice that the directory shows the asset directory that we found in dirbuster. Navigating to that webpage we see the following

pickle_assets_directory

The directory have gifs and jpgs, nothing of importance to solve the challenge.

Let’s move on to question 2.pickle_second_ingredient_question

We know this application is vulnerable to command injection, let’s see if we can perform a directory traversal to view other parts of the application. Going back to the directory  listing we notice there’s a clue.txt file. Opening the file we see the following

pickle_clue_txt

Our hunch was correct, we need to look around the file system to find the next ingredient. pickle_directory_traversal

In the above command we’re doing a directory traversal to move up to the root directory, list all of the files in long form (ls -al), and print the working directory to make sure we’re in the correct folder (pwd). Doing this we get the below screenshot.

pickle_root_directory

We’re viewing the root level directory, so our command(s) were a success! We notice a lot of folders, but at this time two are useful for us. The first is home, which in every  Linux system ever user has a home directory. The second is root (admin/super user) which can only be accessed through the admin. We’ll come back to root later. Let’s see if we can navigate to the home directory.

pickle_change_home_directory

pickle_listing_home_directory

Executing the command above, we’re now in the /home directory! We notice there are two folders, rick and Ubuntu. The Ubuntu folder is from the operating system. Let’s explore the rick folder and see what we can find.

pickle_change_rick_directory

Changing to the rick directory we see the second ingredient!

pickle_list_second_ingredient_rick_directory

pickle_less_second_ingredient

Using the less command we open the second ingredient. Note: The filename is in quotations due to spacing. Without the quotations Linux would interpret the second in second ingredients.

pickle_second_ingredient_answer

We now have our second ingredient, let’s answer the final question.

pickle_third_ingredient_question

Remember in the beginning of this walkthrough, I mentioned that another folder – root is of particular interest to us and only the admin or superuser is the only user to access this folder. Let’s see if we can elevate our privileges to the admin and view this folder.

pickle_sudo_listing

Before we can access this folder, let’s run the sudo -l command to see what privileges we have on this box.

Executing this command we see that we can execute ANY command on this box WITHOUT a password (ALL NOPASSWD: ALL). This surely is NOT good security! Let’s use the sudo command with the listing (ls) with the root folder and see what we can find.

pickle_sudo_listing_as_root

Executing the command, we see that there are two files in the /root folder. One of them is named 3rd.txt. Could this be our third ingredient? Let’s see.

pickle_access_root_listing

Executing the sudo command in conjunction with the less command on the 3rd.txt file, we see that we do indeed have the third and final ingredient.

pickle_less_root_third_ingredient

pickle_third_ingredient

Challenge solved!

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@TryHackMe – Basic Pentesting Room

Another day, another challenge.

Today’s blog post – I will give a walk-through on a boot-to-root room called, “Basic Pentesting Room”. This boot to root is perfect to get practice in preparation for the OSCP.

Let’s get started.

Logging into TryHackMe with your credentials and heading into the room we see the following:

TryHackMe1

OK, we have tasks to complete and we will learn the following skills – brute forcing, hash cracking, service enumeration, and Linux enumeration.

The first question is:

TryHackMe2

Clicking the deploy button at the top we get the following:

tryhackme

Second question is:

TryHackMe3

OK, we need to find the services exposed. What can we do?

One solution is to use nmap -sV (TCP scan) <IP address>

In this case it would be nmap -sV 10.0.0.204. Doing this we see the following screenshot:

tryhackme_nmap

Success! We now have the services.

TryHackMe4

Let’s use dirb to find the hidden directories. See the following screenshot:

tryhackme_dirb

Our hidden directory is development.

TryHackMe5

Reviewing our enumeration we see that ports 139 and 445 are open. These ports are used for SMB (Server Message Blocks) which are HIGHLY vulnerable. Let’s run the command enum4linux and see what we find.

tryhackme_smbtryhackme_smb2

We found two users: kay and jan

Question #5!

TryHackMe6

First, entering kay, I received an error. Let’s try entering jan. Success!

TryHackMe7

Let’s fire up Hydra which is password cracking tool with the password list of rockyou (this password list is used a lot in Kali and even in the OSCP… hint, hint!)

tryhackme_hydra

TryHackMe8

The service we use to access the server is SSH.

TryHackMe9

tryhackme_jantryhackme_jan2

TryHackMe10

kay

TryHackMe11

Since we have a new user (kay) and we have a ssh folder that lists the public key we can try to get the password.

TryHackMe12

From question #10 we have the user (kay) and a public key how can we go about cracking the key?

Doing a quick Google search, I was presented with the following link.

Scrolling down we see the following:

ssh_command

Let’s see if we can recreate this to find the passphrase. Using the ssh2john we created the hash.

tryhackme_ssh2johntryhackme_zip

Next we’ll use John The Ripper with the famous rockyou wordlist to see if we can crack the passphrase.tryhackme_kay1We were successful! The passphrase is beeswax. Let’s try to ssh with kay’s private key and see if we can get in.

tryhackme_kay2

Entering the passphrase we see that we were able to successfully log into the kay account! Just to be sure I issued the command of whoami (don’t mind the fat fingering!)

tryhackme_kay_listing

tryhackme_kay_passwordNext, we run the list command to see what we’re working with. We see a pass.bak file, let’s see if this lists the password. Opening the file we see the password. Score!

Let’s run sudo -l, which will show us what commands kay can run as root. We’re prompted with the password and we entered the password that we just acquired. We’re presented with all of the commands that kay can run, and we see that kay can execute all commands as root. Great, this will be helpful for us.

There’s another file that is important in the directory – bash_history. Bash_history is useful because it shows all the commands the user executed before logging off. Let’s open the file.

tryhackme_bash_historytryhackme_listing_2

After opening the file we see a lot of commands. There is one that is very useful – sudo su. If working correctly, running this command we will change from the kay user to root. In other words we would do privilege escalation – where we start as a non-admin user and through improper configuration change to a root user. Let’s try the command and see if it works.

tryhackme_sudo_su

Running the sudo su command, and typing whoami, we see that we’re now root! We do another directory  listing which shows the files from before, so no change. Let’s see if we can get into the root directory.tryhackme_kay6

Changing to the root directory we see that there is a flag.txt file. Opening this file we presented with the verbiage above. We solved the challenge!