Cybersecurity Internship - Task 1: Network Port Scanning

Objective

The objective of this task was to discover open ports on devices in a local network to understand network exposure using Nmap on Kali Linux.

Tools Used

• Nmap: A powerful network scanning tool for discovering hosts and services.
• Kali Linux: A Linux distribution designed for cybersecurity tasks.

Procedure

1. Network Interface Configuration

First, the network interfaces of the Kali Linux virtual machine were checked using the ip command. The relevant details:

• IP Address: 192.168.247.140
• Interfaces:
  • lo (Loopback): 127.0.0.1/8
  • eth0: 192.168.247.140/24
  • docker0: 172.17.0.1/16 (currently down)

2. Nmap Scans Performed

a. Stealth Scan (-sS) on Local Machine

• Command: nmap -sS 192.168.247.140
• Result: Only port 22/tcp (SSH) was found open.

b. Stealth Scan (-sS) on Entire Subnet

• Command: nmap -sS 192.168.247.0/24
• Results:
  • 192.168.247.1: Ports 135/tcp (msrpc), 139/tcp (netbios-ssn), 445/tcp (microsoft-ds), 3306/tcp (mysql) open.
  • 192.168.247.2: Port 53/tcp (domain) open.
  • 192.168.247.254: All ports filtered.
  • 192.168.247.140: Port 22/tcp (SSH) open.

c. TCP Connect Scan (-sT) on Local Machine

• Command: nmap -sT 192.168.247.140
• Result: Only port 22/tcp (SSH) was found open.

d. Comprehensive TCP Scan (All Ports)

• Command: sudo nmap -p- -sS -T4 192.168.247.140
• Result: Ports 22/tcp (SSH) and 1716/tcp (XMSG) were found open.

3. Open Ports and Their Risks

a. SSH (Port 22)

• Purpose: Secure remote administration.
• Risks:
  • Brute-force attacks targeting weak credentials.
  • Vulnerabilities in outdated SSH versions (e.g., CVE-2023-38408).
  • Privilege escalation if default/weak credentials are used.
  • MITM attacks if encryption is misconfigured.
• Mitigation:
  • Use key-based authentication.
  • Change the default port or restrict access to trusted IPs.
  • Enable fail2ban to block brute-force attempts.

b. XMSG (Port 1716)

• Purpose: Typically associated with messaging services or network analysis tools like Xplico.
• Risks:
  • Potential backdoor or malware communication channel.
  • Data leakage if the service handles sensitive data without encryption.
  • Exploitable vulnerabilities (e.g., RCE, DoS) in outdated software.
• Mitigation:
  • Verify the service running on this port.
  • Disable the service if unnecessary.
  • Monitor for suspicious traffic.

Conclusion

The scans revealed two open ports on the local machine (192.168.247.140):

1. SSH (Port 22): Essential for remote management but requires hardening.
2. XMSG (Port 1716): Non-standard port that needs further investigation to ensure it is not a security risk.

The subnet scan also identified other devices with open ports, highlighting the importance of securing all networked devices to reduce attack surfaces.

Repository Contents

• Task 1.pdf: Detailed scan report and analysis.
• README.md: Summary of the task (this file).