> 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-vulnerabilities/deserialization-yaml-attack/des-yaml-base64-url-pentesting-web.md).

# Deserialización YAML Base64 URL

En el **URL**, el contenido mostrado en la descripción está codificado en **base64**:

<figure><img src="/files/48a14f60d2a42df001edb0319830fe02d854c7e1" alt=""><figcaption></figcaption></figure>

Si decodificamos el texto base64, vemos que esto concuerda efectivamente con el texto:

<figure><img src="/files/92fdcf98e4bdb41b2b2cbb38b0ad5e3f2503d9c0" alt=""><figcaption></figcaption></figure>

Realizamos una prueba para verificar si podemos **modificar este contenido** por nuestra parte. Es necesario añadir "yaml:":

<figure><img src="/files/cb665ec1fb607e946720a967cd2cc1cc72fa3c97" alt=""><figcaption></figcaption></figure>

<figure><img src="/files/3ae7c1d48200d1bbd3fb329fb6371a331c6c3e14" alt=""><figcaption></figcaption></figure>

Luego intentamos inyectar comandos, en este caso el **id** comando, de la siguiente manera:

```bash
yaml: !!python/object/apply:subprocess.check_output ['id']

```

<figure><img src="/files/be1e4da3c2ce3de012eca39a71bcf2c79a80aa06" alt=""><figcaption></figcaption></figure>

<figure><img src="/files/bc4adbfa2e751a4660b696ac4012c21310a89e30" alt=""><figcaption></figcaption></figure>


---

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