HackTheBox Writeup — Passage

Hello Guys , I am Faisal Husaini. My username on HTB is “feodore” . Also join me on discord.

The IP of this box is

Running NMAP full port scan on it , we get

We got only 2 Open Ports that too for SSH and Web

Moving towards the Web Part

Checking the IP in the browser, we get a RSS Feed page

Scrolling down further in the page, we see that it is powered by CuteNews

Clicking on the RSS button on the above which we saw before , it redirects us to rss.php on the CuteNews web directory

We can see that the server has impleted Fail2Ban, so running Gobuster and other fuzzers will be of no use as it will ban us after several request

Now we try to just access the CuteNews directory, it leads us to the login page

If we look clearly, we can see the CuteNews version ,i.e, 2.1.2 and now moving onto searching for potential exploit through searchsploit

We have an Authenticated Arbitrary File Upload vulnerability on this version, since we dont have any credentials so we will register a new user and then login

As soon as we register, it redirects us to the dashboard with our newly created user

Clicking on the Personal Options, it redirects us to the user settings page and from there we can upload our avatar

We will use a small php web shell to upload in the avatar section

Now we intercept the upload functionality into burp and modify the settings and add the GIF code and change the MIME type to JPEG so that we can bypass the restriction

After sending the request, we can see that our file got uploaded successfully

We can right click and view the image to see the location of the shell

Now we can confirm that we have code execution successfully

Getting reverse shell and checking out netcat listener

We have shell as www-data and now move onto user privilege escalation

Checking into the /CuteNews/cdata/users in the webroot directory, we have a file named lines which has many base64 encoded strings

One of the base64 encoded strings had serialized objects which contained password for user paul which was SHA-256 hashed

We cracked the password online and then switched to user paul

We have our user flag here and then move to privilege escalation to root

Checking the SSH directory of the current user, we see that it has public and private keys which can be used for the other user nadav on the box

So we directly SSH to the other user and get in

Checking the current id of the user , we see that the current user is in the sudoer’s group but we cant use sudo here as it will require password which we dont know in this case

When running linpeas script, we see that the server has USBCreator installed which has a vulnerability where we can use take advantage of the sudo which wont require password , to know more about the vulnerability check the references section in the end of this writeup

To get root shell, we will first upload our SSH to the box and then move further to exploit the vulnerability

The below commands is what stated in the explanation of the writeup, here we upload the ssh key to the root’s ssh folder

Hacker | Bug Hunter | Python Coder | Gamer | Reverse Engineering Lover

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