Blocky was another standard box with a few potential rabbit holes to fall down. There was also a 2nd potential method of gaining information through phpmyadmin which i didnt investigate.

Nmap scan

21/tcp   open   ftp     ProFTPD 1.3.5a
22/tcp   open   ssh     OpenSSH 7.2p2 Ubuntu 4ubuntu2.2 (Ubuntu Linux; protocol 2.0)
| ssh-hostkey:
|   2048 d6:2b:99:b4:d5:e7:53:ce:2b:fc:b5:d7:9d:79:fb:a2 (RSA)
|   256 5d:7f:38:95:70:c9:be:ac:67:a0:1e:86:e7:97:84:03 (ECDSA)
|_  256 09:d5:c2:04:95:1a:90:ef:87:56:25:97:df:83:70:67 (ED25519)
80/tcp   open   http    Apache httpd 2.4.18 ((Ubuntu))
|_http-generator: WordPress 4.8
|_http-server-header: Apache/2.4.18 (Ubuntu)
|_http-title: BlockyCraft – Under Construction!
8192/tcp closed sophos

Full port scan

21/tcp    open   ftp
22/tcp    open   ssh
80/tcp    open   http
8192/tcp  closed sophos
25565/tcp open   minecraft

Web server directory bruteforce

[06:51:41] 200 -   51KB - /
[06:52:26] 301 -  309B  - /wiki  ->
[06:52:39] 301 -  315B  - /wp-content  ->
[06:53:51] 301 -  312B  - /plugins  ->
[06:54:59] 301 -  316B  - /wp-includes  ->
[06:56:13] 301 -  315B  - /javascript  ->

Directories mention ‘wp-content’ and ‘wp-includes’ which are wordpress directories so theres a solid chance we will be interacting with wordpress.

User enumeration

Since we know wordpress is running, we can enumerate the site with wpscan. Wpscan manages to pull the username ‘notch’ from the rss feed.

Initial shell

Going back to recon through the ‘plugins’ directory we get access to a ‘cute file browser’ with 2 files:

- Blockycore.jar
- griefprevention.jar

We can use online decompilers to decompile the java into somewhat readable code. From the blockycore file we get credentials that are hardcoded.

public class BlockyCore {
public String sqlHost = "localhost";
public String sqlUser = "root";
public String sqlPass = "8YsqfCTnvxAUeduzjNSXe22";

Logging in to ssh with user ‘notch’ and that password gives us our foothold and user flag.

Privilege escalation

A sudo check reveals instantly what our method of gaining root privs will be.

notch@Blocky:~$ sudo -l
[sudo] password for notch: <ssh_pw>
Matching Defaults entries for notch on Blocky:
env_reset, mail_badpass, secure_path=/usr/local/sbin\:/usr/local/bin\:/usr/sbin\:/usr/bin\:/sbin\:/bin\:/snap/bin

User notch may run the following commands on Blocky:

‘sudo su’ gives us root.