#Introduction

In this write-up, we will solve the “Appointment” machine from the Hack The Box Starting Point series by performing basic enumeration and exploiting common vulnerabilities to gain access to the target system.

#Setup

Download a VPN configuration file from the webpage and connect to it via sudo openvpn file.ovpn.

NOTE: Replace file.ovpn with your VPN configuration file name.

To verify the connectivity and availability of the target, we can run the ping command with the IP address of the target machine.

#Enumeration

Run nmap -sV <ip_addr> to scan the target for open ports and service versions:

Starting Nmap 7.95 ( https://nmap.org ) at 2026-05-08 14:58 IST
Nmap scan report for 10.129.142.25
Host is up (0.17s latency).
Not shown: 999 closed tcp ports (reset)
PORT   STATE SERVICE VERSION
80/tcp open  http    Apache httpd 2.4.38
Service Info: Host: 127.0.0.1
 
Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 39.42 seconds

The scan results indicate that port 80 is running an Apache web server. Navigating to http://<ip_addr> in the browser presents a login page, suggesting that the web application may be the primary attack surface.

#Exploitation

Since the target presents a login form, we first attempted several common default credential combinations such as:

admin:admin
guest:guest
user:user
root:root
administrator:password

None of these credentials were successful. With default logins ruled out, the next step was to test the authentication form for a possible SQL Injection vulnerability.

NOTE: In MySQL, the # character is used to comment out the remainder of a query.

Using this knowledge, we can attempt a basic SQL Injection by entering the following payload in the username field while leaving the password field blank:

Username: admin'#
Password:

This payload may cause the application to ignore the password check entirely, potentially allowing authentication as the admin user.

Upon successful exploitation, the webpage displays the flag:

Congratulations!
 
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