Belajar Security Tester - Network Security Testing Basics

#Pendahuluan

Setelah di episode 17 kita menguji third-party dependencies, pada episode ini kita beralih ke lapisan yang lebih rendah: network. Security tester harus memahami jaringan karena banyak vulnerability berakar pada konfigurasi network yang salah.

#Service Scanning dengan Nmap

#Basic Scanning

bash

# Scan target untuk open ports
nmap -sV -sC target-ip
 
# Scan cepat (top 1000 ports)
nmap -F target-ip
 
# Scan semua ports
nmap -p- target-ip
 
# Service version detection
nmap -sV -p 80,443,8080 target-ip

#NSE Scripts

bash

# Vulnerability scan
nmap --script vuln target-ip
 
# SSL/TLS testing
nmap --script ssl-enum-ciphers -p 443 target-ip
 
# HTTP security headers
nmap --script http-security-headers -p 80 target-ip

#TLS Testing

#Certificate Analysis

bash

# Cek certificate details
openssl s_client -connect target:443 < /dev/null 2>/dev/null | \
  openssl x509 -noout -dates -subject -issuer
 
# Cek certificate chain
openssl s_client -connect target:443 -showcerts < /dev/null
 
# Cek TLS version support
nmap --script ssl-enum-ciphers -p 443 target

#TLS Configuration Issues

text

Yang Harus Dicek:
├── TLS version: hindari SSLv3, TLS 1.0, TLS 1.1
├── Cipher suites: hindari weak ciphers (RC4, DES, 3DES)
├── Certificate validity: pastikan belum expired
├── HSTS: pastikan header Strict-Transport-Security ada
└── Certificate pinning: untuk aplikasi mobile

#Open Ports & Services

bash

# Quick scan
nmap target-ip
 
# Detailed scan
nmap -sV -sC -O target-ip
 
# UDP scan (lambat tapi penting)
nmap -sU target-ip
 
# Scan untuk menemukan web servers
nmap -p 80,443,8080,8443 target-ip

#Firewall Rules Testing

bash

# Cek apakah firewall memblokir port tertentu
nmap -p 22 target-ip  # SSH
 
# Bypass dengan technique
nmap -f target-ip  # Fragment packets
nmap -D RND:10 target-ip  # Decoy scan

#Network Assessment Checklist

text

Network Security Assessment:
├── Port scanning: open ports & services
├── Service enumeration: version & configuration
├── TLS testing: versions, ciphers, certificates
├── Firewall testing: rules & bypass techniques
├── DNS enumeration: subdomains & records
└── Wireless (jika applicable): encryption & authentication

Note

Network testing untuk security tester berbeda dari penetration tester — security tester fokus pada konfigurasi dan hardening, bukan exploit development.

#Praktik: Network Assessment

bash

# 1. Port scan
nmap -sV target-ip
 
# 2. TLS test
nmap --script ssl-enum-ciphers -p 443 target-ip
 
# 3. Vulnerability scan
nmap --script vuln target-ip
 
# 4. HTTP security headers
nmap --script http-security-headers -p 80 target-ip

#Penutup

Nmap: tool utama untuk service scanning dan enumeration.
TLS testing: pastikan TLS 1.2+, hindari weak ciphers.
Open ports: identifikasi semua open ports dan services.
Firewall testing: test rules dan bypass techniques.

Di episode 19 selanjutnya kita akan membahas logging, monitoring & detection test — testing logging coverage, detection rules, dan alerting pada aplikasi. Sampai jumpa di episode 19!