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Introduction:
Bug bounty programs, like the Kahf Yazılım A.Ş. Vulnerability Disclosure Program (VDP), have democratized cybersecurity, allowing researchers worldwide to contribute to digital safety. Mastering the tools of the trade is paramount for anyone looking to transition from enthusiast to a recognized hunter on platforms like Bugcrowd, HackerOne, and Meta. This guide provides a foundational arsenal of verified commands and techniques to systematically uncover critical vulnerabilities.
Learning Objectives:
- Master fundamental reconnaissance and enumeration techniques to expand your attack surface.
- Develop proficiency in identifying and exploiting common web application vulnerabilities.
- Understand essential post-exploitation and privilege escalation tactics for comprehensive security assessments.
You Should Know:
1. Passive Subdomain Enumeration
Effective reconnaissance is the cornerstone of any successful bug bounty hunt. Discovering all associated subdomains dramatically widens the attack surface.
Command:
subfinder -d target.com -silent | httpx -silent
Step-by-step guide:
This two-part command leverages specialized tools. First, `subfinder` passively queries numerous public sources (like DNS databases, certificate transparency logs) to find subdomains for target.com. The `-silent` flag removes extraneous banners. The output is then piped (|) to httpx, which probes each discovered subdomain to confirm if it’s active and running a web service. This saves time by filtering out inactive domains, providing a clean list of live targets for further testing.
2. Active Subdomain Bruteforcing
Passive enumeration can miss hidden subdomains. Active bruteforcing uses wordlists to discover targets that may not be publicly indexed.
Command:
ffuf -w /usr/share/wordlists/seclists/Discovery/DNS/namelist.txt -u https://target.com -H "Host: FUZZ.target.com" -fs 0
Step-by-step guide:
`Ffuf` is a fast web fuzzer. Here, `-w` specifies a wordlist containing common subdomain names (like “api,” “admin,” “test”). The `-u` flag points to the target’s main domain. The magic happens with the `-H` flag, which sets the HTTP `Host` header for each request to FUZZ.target.com, where `FUZZ` is replaced by each word in the list. The `-fs 0` filter hides responses of a specified size (in this case, 0), which typically filters out non-existent domain errors, showing only successful hits.
3. Full-Scope Port Scanning with Nmap
Identifying open ports on discovered assets reveals services like SSH, databases, or custom admin panels that could be vulnerable.
Command:
nmap -sC -sV -p- -T4 -oA full_scan target.com
Step-by-step guide:
This comprehensive Nmap command performs a deep scan. `-sC` runs default scripts for common vulnerability checks, while `-sV` probes open ports to determine service/version info. The `-p-` flag instructs Nmap to scan all 65,535 ports, not just the common ones. `-T4` speeds up the scan (use cautiously to avoid being blocked), and `-oA` outputs the results in all major formats (normal, XML, grepable) with the filename prefix full_scan.
4. Automated Web Vulnerability Scanning
While manual testing is crucial, automated scanners can quickly identify low-hanging fruit and common misconfigurations.
Command:
nuclei -u https://target.com -t /path/to/nuclei-templates/ -severity medium,high,critical -rate-limit 100
Step-by-step guide:
`Nuclei` uses community-powered templates to detect vulnerabilities. The `-u` flag specifies the target URL. `-t` points to the directory containing the vulnerability templates. The `-severity` filter ensures only medium, high, and critical findings are reported, reducing noise. The `-rate-limit` prevents overwhelming the target server with too many requests per second, which is essential for ethical testing and avoiding disruption.
5. SQL Injection Detection with SQLmap
SQL Injection remains a critical vulnerability, allowing attackers to manipulate backend databases.
Command:
sqlmap -u "https://target.com/page.php?id=1" --batch --level=3 --risk=2 --dbs
Step-by-step guide:
This `sqlmap` command tests the parameter `id=1` for SQL injection flaws. The `–batch` flag runs the tool in non-interactive mode, using default choices. `–level` and `–risk` increase the depth and aggressiveness of the tests. The `–dbs` flag instructs sqlmap to attempt to enumerate the names of all available databases if a vulnerability is found, demonstrating the potential impact.
6. Cross-Site Scripting (XSS) Probe
Testing for XSS involves injecting scripts into input fields to see if they are executed in a user’s browser.
Command:
echo 'https://target.com/search?q=' | waybackurls | gf xss | qsreplace '"><script>alert(1)</script>' | airbase -x
Step-by-step guide:
This pipeline is a powerful recon-to-exploit workflow. `echo` and `waybackurls` fetch historical URLs. `gf xss` filters these for parameters likely to be XSS-prone. `qsreplace` injects a classic XSS payload ("><script>alert(1)</script>) into every parameter found. Finally, `airbase` (or a similar tool like httpx) sends the requests and checks for a reflected response, indicating a potential vulnerability.
7. API Endpoint Discovery and Testing
Modern applications are API-heavy, and these endpoints are prime targets for hunters.
Command:
gau target.com | grep "api" | sort -u | httpx -path /api/v1/users -status-code
Step-by-step guide:
`gau` (GetAllUrls) fetches known URLs from AlienVault’s OTX and Common Crawl. The output is piped to `grep` to filter for URLs containing “api.” `sort -u` removes duplicates. Finally, `httpx` is used to probe a specific endpoint pattern (/api/v1/users) across all discovered domains and report the HTTP status codes (e.g., 200 for success, 403 for forbidden, 404 for not found), helping identify accessible and hidden API paths.
8. Sensitive Information Exposure Scan
Developers often accidentally leave sensitive files (configs, backups, keys) in publicly accessible directories.
Command:
ffuf -w /usr/share/wordlists/seclists/Discovery/Web-Content/common.txt -u https://target.com/FUZZ -e .bak,.txt,.sql,.old -fc 403
Step-by-step guide:
This `ffuf` command fuzzes for common files and backups. The `-w` flag uses a wordlist of common filenames and directories. The `-e` flag adds these backup file extensions to each fuzzing attempt. The `-fc 403` filters out “Forbidden” responses, which are common but uninteresting, allowing you to focus on “200 OK” (found) or “301 Moved” responses that indicate a potentially exposed resource.
9. Linux Privilege Escalation Check
Once initial access is gained, the next step is to escalate privileges, often to the root user.
Command:
find / -perm -u=s -type f 2>/dev/null
Step-by-step guide:
This `find` command searches the entire filesystem (/) for files with the SetUID bit set (-perm -u=s). SetUID binaries run with the privileges of the file’s owner, often root. If a non-root user can manipulate such a binary, they can potentially escalate privileges. The `2>/dev/null` part suppresses all error messages, cleaning up the output to show only successful finds.
10. Windows Privilege Escalation Enumeration
On Windows systems, misconfigured service permissions are a common path to privilege escalation.
Command (PowerShell):
Get-WmiObject -Class Win32_Service | Where-Object {$_.StartName -eq "LocalSystem"} | Select-Object Name, StartName, PathName
Step-by-step guide:
This PowerShell command queries Windows Management Instrumentation (WMI) for all services. It filters the list to show only services running under the highly privileged `LocalSystem` account. By reviewing the `PathName` of these services, a hunter can identify if the path to the executable is writable by a lower-privileged user, which could allow for binary replacement and privilege escalation.
What Undercode Say:
- The barrier to entry for bug bounty hunting is lower than ever, but the path to consistent success requires deep, methodological expertise and automation.
- The most successful hunters are not just tool runners; they are creative problem-solvers who understand the underlying technology stacks and can chain minor flaws into critical findings.
The post from Nazmul Hossain Nirab highlights a growing global trend where technical recognition is no longer confined to traditional tech hubs. The tools and commands outlined here are the great equalizers. However, the real differentiator is the analytical mindset—the ability to see a 403 Forbidden response not as a dead end, but as a potential challenge to be bypassed with header manipulation or parameter pollution. The future of bounty hunting will be dominated by those who can automate the boring stuff to free up time for advanced, manual exploitation techniques that scanners cannot replicate. This evolution will push programs to defend more complex attack surfaces, raising the security bar for everyone.
Prediction:
The normalization of VDPs and bug bounties will force a fundamental shift in software development lifecycle (SDLC). Security will become a non-negotiable, integrated component from the design phase, driven by the constant, global scrutiny of ethical hackers. AI will begin to play a dual role: both as an assistant to hunters for generating sophisticated payloads and to defenders for proactively identifying and patching bug-class vulnerabilities at scale, leading to an automated “arms race” in cybersecurity.
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IT/Security Reporter URL:
Reported By: X1337loser The – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
