> 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/linkvortex-hackthebox-writeup.md). # LinkVortex HackTheBox Writeup LinkVortex HackTheBox Easy Linux machine writeup covering Subdomain Enumeration, Extracting Information from .git Directory (Git-Dumper), Information Leakage, LFI Exploitation (Ghost), with practical {% embed url="" %} {% hint style="warning" %} **Skills:** * Subdomain Enumeration * Extracting Information from .git Directory (Git-Dumper) * Information Leakage * LFI Exploitation (Ghost) * Abusing Sudo Privileges via Script (Double Symbolic Link) {% 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.

**Configuration of the /etc/hosts file** We add the target's IP address to our `/etc/hosts` file to facilitate local DNS resolutions.

**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 linkvortex.htb -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 80**

**Port Version Scan with Nmap:** Use Nmap to scan service versions and save the output in the "targeted" file: ```bash nmap -sCV -p22,80 linkvortex.htb -oN targeted ```

### **Directory Enumeration** ```bash wfuzz -c -t 100 --hc=404,301 -w /usr/share/SecLists/Discovery/Web-Content/directory-list-2.3-medium.txt http://linkvortex.htb/FUZZ/ ```

### Panel Admin - Ghost

### **Discovery of a Sub-Domain** We search for subdomains associated with `linkvortex.htb` using gobuster. ```bash gobuster vhost -u http://linkvortex.htb --append-domain -w /usr/share/SecLists/Discovery/DNS/subdomains-top1million-110000.txt -t 100 ``` We find the subdomain `dev.linkvortex.htb`. Here is the command to perform this search:

Once the subdomain is found, we add it to the `/etc/hosts` file for easier access:

#### **Searching Directories in the New Subdomain** We search existing directories on the `dev.linkvortex.htb` subdomain using `gobuster`: ```bash gobuster dir -u http://dev.linkvortex.htb/ -w /usr/share/SecLists/Discovery/Web-Content/common.txt -t 100 ``` We discover the `.git` directory, which could indicate an exposed Git repository.

### **File Extraction with Git-Dumper** We use the `git-dumper` tool to extract files from the `.git` directory and analyze them: ```git git-dumper http://dev.linkvortex.htb/.git .git ```

This allows us to obtain sensitive files, including a test file located in `ghost/core/test/regression/api/admin/authentication.test.js`, where we find a password:

**Password found:** ```parser OctopiFociPilfer45 ```

### **Login to the Ghost Admin Panel** With this password, we try to connect to the Ghost administration panel using the `admin@linkvortex.htb` email address: * **Email** : `admin@linkvortex.htb` * **Password**: `OctopiFociPilfer45`

## Vulnerability GHost - LFI {% embed url="" %}

> During the port scan, we identified that the version of Ghost used (v5.58) is vulnerable to an LFI (Local File Inclusion) vulnerability, identified by CVE-2023-40028. To exploit this vulnerability, we download the exploit script and modify the target URL to point to our Ghost instance.

Here is the command to run the exploit: ```bash ./LFI.sh -u admin@linkvortex.htb -p OctopiFociPilfer45 ``` We then get a shell and can display files, like `/etc/passwd`.

**Access to an Internal Route via LFI** In the `.git` directory, we spotted a Docker file which provides us with an internal route to access a session: `/var/lib/ghost/config.production.json`.

We use LFI to list files and find the credentials of a user named Bob:

**Bob's credentials:** * **User**: `bob@linkvortex.htb` * **Password**: `fibber-talented-worth` We connect to the target machine via SSH using Bob's credentials: ### Flag user.txt :) We use the password `fibber-talented-worth` to log in and access the file `user.txt`, where we find the flag.

## Flag root.txt :) ### SUDO - Clean/\_synLink.sh We are looking for a vulnerability that allows for privilege escalation. We discover a file with SUID permissions.

#### **Symlink Cleanup Script Analysis** > We analyze a script named `clean_symlink.sh`, which checks if the file provided as an argument is a symlink pointing to a `.png` file. If the symlink points to a critical file, the script deletes it. Otherwise, it moves the symlink to the `/var/quarantined/` directory. If the `CHECK_CONTENT` environment variable is set to `true`, the script attempts to read the contents of the file. Here is the command to create the symlinks necessary for exploitation: ```bash ln -s /root/root.txt flag.txt ln -s /home/bob/flag.txt flag.png ``` Then we run the script with the following command to get the root flag: ```bash sudo CHECK_CONTENT=true /usr/bin/bash /opt/ghost/clean_symlink.sh /home/bob/flag.png ``` We thus obtain the `root.txt` flag.

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