# NotFooter

## Description

> Wonder how http knows what browser i am using...

[url](https://isfcr-notfooter.chals.io/)

## Solution

* From the description, we can conclude that it is referring to the [User-Agent header](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/User-Agent)
* We can see that it is expecting `ctfbrowser` as the User-Agent. This can be done in 2 ways:
  1. Intercept request using **BurpSuite** and change the **User-Agent** header
  2. Using curl

### Using BurpSuite

* Intercept the request using BurpSuite and change the User-Agent header to `ctfbrowser`

![burp1](/files/kDQYk5XFpYboKqEVBGJ0)

* Forward the request and we get the flag

![flag](/files/GTy4oTo0dpoKrl3f7Ml4)

### Using curl

* We can use curl to send a request with a custom User-Agent header

```bash
$ curl -A "ctfbrowser" https://isfcr-notfooter.chals.io/                                   
pesu_ec{h34d3r5_4r3_us3ful}
<title>Special agent</title> 
```

`-A`: To set the User-Agent header

### FLAG:

```
pesu_ec{h34d3r5_4r3_us3ful}
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://j0luuuu.gitbook.io/ctf/isfcr-ec-ctf-2023/notfooter.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.