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Introduction:
The journey from aspiring student to successful bug bounty hunter is paved with curiosity and technical rigor. As demonstrated by a recent researcher who transformed a perceived feature into a validated security flaw, this path requires a deep understanding of the tools and techniques used to uncover hidden vulnerabilities. This article provides a foundational toolkit for modern security research, spanning system reconnaissance, web application testing, and network analysis.
Learning Objectives:
- Master fundamental command-line tools for system reconnaissance and vulnerability discovery.
- Develop proficiency in web application security testing methodologies and associated commands.
- Understand network analysis techniques for identifying service misconfigurations and data exfiltration.
You Should Know:
1. System Reconnaissance and Enumeration
Verified commands for initial target discovery and service enumeration.
`nmap -sV -sC -O -p- 192.168.1.1`
This comprehensive Nmap scan performs service version detection (-sV), runs default scripts (-sC), attempts OS detection (-O), and scans all ports (-p-). Start with identifying your target’s IP range, then run this command to map all open ports, running services, and potential vulnerabilities. The output reveals service banners, potential misconfigurations, and attack surface areas that often hide the types of “clever features” that become bounty-worthy vulnerabilities.
`sudo masscan -p1-65535 192.168.1.0/24 –rate=1000`
For rapid network sweeping, Masscan operates at incredible speeds. Configure the target subnet and port range, adjusting the rate based on network tolerance. This helps quickly identify all active hosts and open ports across an entire network segment before deeper investigation.
`enum4linux -a 192.168.1.105`
Specifically designed for SMB enumeration, this Perl script extracts user lists, share information, group details, and password policy data from Windows systems. Run against SMB-enabled hosts to discover potential lateral movement paths or exposed sensitive data.
2. Web Application Directory and File Discovery
Commands for uncovering hidden endpoints and files.
`gobuster dir -u https://target.com -w /usr/share/wordlists/dirb/common.txt -x php,html,json`
This GoBuster command brute-forces directories and files using common wordlists. Specify the target URL (-u), wordlist path (-w), and file extensions to check (-x). The results often reveal admin panels, backup files, API endpoints, and configuration files that weren’t intended for public access.
`ffuf -w /usr/share/wordlists/SecLists/Discovery/Web-Content/common.txt -u https://target.com/FUZZ -mc 200,301,302`
FFuf is a fast web fuzzer that discovers valid resources. The -w flag specifies the wordlist, -u defines the target URL with FUZZ as the placeholder, and -mc filters for successful HTTP status codes. This frequently uncovers hidden parameters and endpoints that contain vulnerability chains.
`nikto -h https://target.com -C all`
Nikto performs comprehensive web server scans checking for outdated server software, potentially dangerous files, and server misconfigurations. The -C all option shows all cookies found during the scan, which can reveal session management issues.
3. Vulnerability Scanning and Analysis
Automated and manual vulnerability assessment techniques.
`nuclei -u https://target.com -t /path/to/templates -severity medium,high,critical`
Nuclei uses community-powered templates to scan for known vulnerabilities. Specify the target (-u) and template path (-t), filtering by severity to focus on critical issues. This automates detection of common misconfigurations that bounty hunters frequently encounter.
`sqlmap -u “https://target.com/page.php?id=1” –batch –level=3 –risk=3`
For potential SQL injection testing, SQLmap automates the detection and exploitation process. The –batch flag runs non-interactively, while level and risk adjust the thoroughness. Always ensure you have proper authorization before running this against any target.
`testssl.sh https://target.com –html`
This bash-based tool checks SSL/TLS configuration for vulnerabilities including weak ciphers, expired certificates, and protocol support issues. The –html flag generates a readable report documenting cryptographic weaknesses that could lead to data interception.
4. Network Traffic Analysis and Interception
Commands for monitoring and manipulating network traffic.
`sudo tcpdump -i any -w capture.pcap host 192.168.1.100 and port 80`
This tcpdump command captures all traffic to and from a specific host on port 80, writing to a file for later analysis. Use this to examine unencrypted web traffic for sensitive data exposure or to understand application behavior.
`sudo wireshark -k -i eth0 -f “host target.com”`
For real-time packet analysis, Wireshark provides deep protocol inspection. The -k flag starts immediately, -i specifies the interface, and -f applies a display filter. This helps identify unusual network patterns and potential data exfiltration attempts.
`burpsuite`
While GUI-based, Burp Suite is essential for intercepting and manipulating web traffic. Configure your browser proxy to 127.0.0.1:8080, enable interception, and modify requests in real-time to test for input validation flaws, business logic errors, and authentication bypasses.
5. API Security Testing
Modern API vulnerability discovery commands.
`curl -H “Authorization: Bearer $TOKEN” https://api.target.com/v1/users | jq .`
This curl command tests API authentication and response formatting. Pipe to jq for readable JSON output, examining the response for information disclosure, improper access controls, or error messages revealing system details.
`arjun -u https://api.target.com/endpoint –headers “Authorization: Bearer token”`
Arjun discovers hidden API parameters that might not be documented. These undocumented parameters often contain the “feature vs bug” scenarios that lead to successful bounty reports when proper authorization checks are missing.
`kiterunner scan https://api.target.com -w /path/to/wordlists/data/routes-large.kite`
Kiterunner specializes in discovering API routes by matching requests to responses, effectively finding endpoints that traditional directory busting might miss. This reveals legacy versions, admin functions, and deprecated endpoints with known vulnerabilities.
6. Cloud Infrastructure Hardening
Commands for securing cloud environments.
`aws iam get-account-authorization-details`
This AWS CLI command retrieves comprehensive IAM configuration details, helping identify overprivileged roles, unused permissions, and policy violations that could lead to privilege escalation in cloud environments.
`terraform validate`
For infrastructure-as-code security, Terraform validation checks syntax and basic configuration before deployment. Combine with security scanning tools like tfsec or checkov to identify misconfigurations before they reach production.
`docker scan [bash]`
Docker Scan integrates Snyk vulnerability scanning to identify known CVEs in container images. Run this against your Docker images to detect and remediate vulnerabilities in dependencies and base layers before deployment.
7. Post-Exploitation Analysis
Commands for understanding system compromise.
`ps aux –sort=-%mem | head`
This process examination command shows running processes sorted by memory usage, helping identify suspicious applications, cryptocurrency miners, or malware that might have compromised a system during testing.
`netstat -tulnpe`
Display all listening ports with associated processes and user context. This reveals unauthorized services, backdoors, and suspicious network listeners that could indicate persistent access mechanisms.
`find / -type f -name “.pem” -o -name “.key” -o -name “.ppk” 2>/dev/null`
Search for potentially sensitive cryptographic key files that might be exposed. Such discoveries often represent critical security failures and warrant immediate remediation and responsible disclosure.
What Undercode Say:
- The transition from feature to vulnerability represents a fundamental shift in perspective that separates novice researchers from successful bounty hunters
- Comprehensive tool mastery must be paired with creative thinking to identify logic flaws that automated scanners miss
The most successful bug bounty hunters operate with a dual mindset: understanding standard tool usage while constantly questioning expected behaviors. The recent case of a researcher finding bounty in a “clever feature” demonstrates that beyond command proficiency lies the critical ability to recognize when intended functionality creates unintended risk. Modern security research requires both technical execution through verified commands and the analytical rigor to interpret results through an attacker’s lens. The commands provided represent foundational knowledge, but their effective application depends on developing the curiosity to probe deeper than surface-level findings and the persistence to document chainable vulnerabilities that demonstrate real business impact.
Prediction:
As feature complexity increases in modern web applications and API-driven architectures, we’ll see a significant rise in business logic vulnerabilities that evade traditional scanning methodologies. The most valuable future bounty discoveries will increasingly come from understanding complex user workflows, privilege transition points, and data validation boundaries rather than common technical injection flaws. This evolution will require security researchers to develop deeper application-specific knowledge while maintaining their core technical testing capabilities, creating a new class of specialized bounty hunters focused on vertical-specific application security.
🎯Let’s Practice For Free:
IT/Security Reporter URL:
Reported By: Narendra Tiwari – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
