Beyond Subdomains: How Leaked APIs and Postman Workspaces Expose Millions in Bug Bounties + Video

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Introduction:

Traditional subdomain enumeration only scratches the surface of an organization’s attack surface. Advanced bug hunters now target leaked API endpoints, exposed secrets in public code repositories, forgotten cloud assets, and misconfigured Postman workspaces—often yielding critical vulnerabilities that bypass standard reconnaissance.

Learning Objectives:

  • Discover and extract sensitive API keys, tokens, and endpoints from GitHub, GitLab, and Postman public workspaces.
  • Enumerate and exploit cloud misconfigurations (open S3 buckets, Azure blobs, GCP storage) using CLI tools.
  • Build an automated OSINT pipeline to identify forgotten subdomains, leaked credentials, and shadow IT assets.

You Should Know:

  1. Hunting Leaked APIs via GitHub Dorks and Secret Scanning

Attackers and bug hunters alike use GitHub’s search engine to find accidentally committed secrets. This step-by-step guide shows how to manually and automatically discover exposed API credentials, internal endpoints, and configuration files.

Step‑by‑Step Guide – GitHub Dorks & Secret Extraction

  • Step 1: Use GitHub advanced search operators to locate sensitive patterns. Example dorks:
    – `”api_key” language:json`
    – `”secret” extension:env`
    – `”Authorization: Bearer” language:javascript`
    – `”private-key” “BEGIN RSA”`
  • Step 2: Clone repositories matching your dorks (use `git clone` for deeper analysis).
    Linux: `git clone https://github.com/target/repo.git`
    Windows (PowerShell): `git clone https://github.com/target/repo.git`

  • Step 3: Run automated secret scanners locally.

Install `trufflehog` (Linux/macOS):

`curl -sSfL https://raw.githubusercontent.com/trufflesecurity/trufflehog/main/scripts/install.sh | sh -s — -b /usr/local/bin`
Scan a cloned repo: `trufflehog git file://$(pwd)/repo –json | jq ‘.Raw’`
Windows (using WSL or native binary): Download from releases, then `trufflehog.exe git file://C:\repo`

– Step 4: Use `gitleaks` for fast batch scanning.

Linux: `gitleaks detect –source ./repo –verbose`

Windows: `gitleaks.exe detect –source C:\repo –verbose`

What This Does: Identifies hardcoded API keys, OAuth tokens, private keys, and database connection strings that developers mistakenly push to public repos. Validate each secret using curl or Postman before reporting.

  1. Exposed Secrets in Postman Workspaces – Enumeration and Exploitation

Postman collections often contain embedded authentication tokens, environment variables, and internal API endpoints. Many teams accidentally set workspaces to “public,” giving attackers a map of internal architecture.

Step‑by‑Step Guide – Postman Workspace OSINT

  • Step 1: Enumerate public Postman workspaces using search engines.

Google dork: `site:postman.com “workspace” “collection”`

Also check: `https://www.postman.com/explore` and filter by “public”.

– Step 2: Use Postman’s API to fetch workspace metadata without authentication.

Linux curl:

`curl -s “https://api.getpostman.com/workspaces” | jq ‘.workspaces[] | {name, id}’`
(Note: Unauthenticated calls may return limited data; register a free account for higher rate limits.)

  • Step 3: Extract collection details from a discovered workspace ID.
    `curl -s “https://api.getpostman.com/workspaces//collections” | jq ‘.collections[].name’`
  • Step 4: Download a public collection as JSON and parse for secrets.
    `curl -s “https://api.getpostman.com/collections/” -o collection.json`

Then grep for keywords: `grep -iE “api[_-]?key|secret|token|password|Bearer” collection.json`

Windows PowerShell: `Select-String -Pattern “api[_-]?key|secret|token” -Path .\collection.json`

What This Does: Reveals live API endpoints, authentication headers, and environment-specific variables (dev/prod). Use these to craft unauthorized requests or pivot to internal services.

  1. Cloud Misconfigurations – From Forgotten Buckets to Full Account Takeover

Open cloud storage can leak PII, source code, and credentials. Attackers scan for misconfigured S3, Azure Blob, and GCP buckets. This section covers enumeration and hardening.

Step‑by‑Step Guide – Cloud Asset Enumeration (Ethical Testing Only)

  • Step 1: Install cloud CLIs.

Linux: `pip install awscli azure-cli google-cloud-sdk`

Windows: Download MSI installers from AWS, Microsoft, and Google.

  • Step 2: Enumerate open S3 buckets via common naming patterns.

Use `bucket-stream` tool:

`git clone https://github.com/eth0izzle/bucket-stream.git`

`python3 bucket-stream.py -f companyname.txt -l</h2>
<h2 style="color: yellow;">Manual check:aws s3 ls s3://[bucket-name] –no-sign-request`

If successful, list contents: `aws s3 ls s3://vulnerable-bucket –recursive –no-sign-request`

– Step 3: Check Azure blob containers for public read access.
`az storage container list –account-name –connection-string ““` (requires auth)
But public containers: `curl “https://.blob.core.windows.net/?restype=container&comp=list”`

– Step 4: GCP open buckets:
`gsutil ls gs://[bucket-name]` – if permission denied, bucket may be private. No error means public listing.

Mitigation Commands (Defender Side):

  • AWS: `aws s3api put-public-access-block –bucket –public-access-block-configuration BlockPublicAcls=true,IgnorePublicAcls=true`
  • Azure: `az storage container set-permission –name –public-access off`
  • GCP: `gsutil iam ch allUsers:objectViewer gs:// 
    ` (remove this after accidental exposure)</li>
</ul>

<ol>
<li>OSINT for Forgotten Subdomains and Assets Using Certificate Transparency</li>
</ol>

Even after subdomain enumeration, shadow IT assets (test servers, dev dashboards) remain hidden. Certificate Transparency (CT) logs provide a historical record of every SSL/TLS certificate issued.

<h2 style="color: yellow;">Step‑by‑Step Guide – CT Log Recon</h2>

<ul>
<li>Step 1: Query crt.sh for a domain. </li>
</ul>

<h2 style="color: yellow;">Linux curl:</h2>


`curl -s "https://crt.sh/?q=%.target.com&output=json" | jq -r '.[].name_value' | sort -u` 

<h2 style="color: yellow;">PowerShell (Windows):</h2>


`Invoke-RestMethod -Uri "https://crt.sh/?q=%.target.com&output=json" | Select-Object -ExpandProperty name_value | Sort-Object -Unique`

- Step 2: Use `subfinder` for automated passive recon.

<h2 style="color: yellow;">`subfinder -d target.com -all -silent | tee subs.txt`</h2>

<ul>
<li>Step 3: Probe for live HTTP/HTTPS services using <code>httpx</code>. </li>
</ul>

<h2 style="color: yellow;">`cat subs.txt | httpx -status-code -title -tech-detect -follow-redirects`</h2>

<ul>
<li>Step 4: Check for forgotten assets exposing admin panels or debug endpoints. 
Example: `curl -k https://dev-admin.target.com/health` or `curl http://staging-api.target.com/swagger/index.html`</li>
</ul>

What This Does: Discovers subdomains that do not appear in DNS brute‑forcing but were legitimately issued a certificate. Many forgotten test environments use “dev”, “staging”, “beta” prefixes and lack proper security controls.

<ol>
<li>Automating the Recon Pipeline with Bash and PowerShell</li>
</ol>

Combine all the above steps into a single script for continuous monitoring. Below are lightweight automation examples.

<h2 style="color: yellow;">Linux Bash Automation Script</h2>

[bash]
!/bin/bash
DOMAIN=$1
echo "[] Starting advanced recon for $DOMAIN"
 GitHub dorks via CLI (requires gh and jq)
gh search code "api_key" --repo="$DOMAIN/" --limit=100 | tee gh_leaks.txt
 CT log extraction
curl -s "https://crt.sh/?q=%.$DOMAIN&output=json" | jq -r '.[].name_value' | sort -u > ct_subs.txt
 Run secret scanner on discovered repos (assumes repos.txt)
for repo in $(cat repos.txt); do
trufflehog git "$repo" --json | jq '.SourceMetadata' >> secrets.json
done

    Windows PowerShell Automation

    $domain = "target.com"
Write-Host "[] Recon on $domain"
 CT logs
$ct = Invoke-RestMethod "https://crt.sh/?q=%.$domain&output=json"
$ct.name_value | Sort-Object -Unique | Out-File ct_subs.txt
 Subfinder (ensure subfinder.exe in PATH)
& subfinder -d $domain -silent | Out-File subs.txt
 Probe with curl
Get-Content subs.txt | ForEach-Object { curl -s -o NUL -w "$_ <code>t %{http_code}</code>n" $_ }

    What This Does: Automates the discovery of leaked secrets, forgotten subdomains, and live endpoints. Run these regularly to stay ahead of attackers or, as a defender, to identify your own exposure.

    1. API Security Hardening – Preventing the Leaks You Just Found

    Understanding exploitation enables effective mitigation. For defenders and API owners, these steps close the gaps that bug hunters exploit.

    Step‑by‑Step Guide – Hardening APIs and Workspaces

    • Step 1: Implement pre‑commit hooks to block secrets.
      Linux: Install `detect-secrets` and run `detect-secrets scan –baseline .secrets.baseline`

    Add to `.git/hooks/pre-commit`: `detect-secrets scan –baseline .secrets.baseline –fail-on-audit-issues`

    • Step 2: Rotate any exposed credentials immediately. Use cloud IAM to deactivate leaked keys.
      AWS CLI: `aws iam update-access-key –access-key-id –status Inactive`
    • Step 3: Lock down Postman workspaces – change to “private” and rotate any API keys stored in environment variables. Educate teams never to commit `.postman` folders to GitHub.

    • Step 4: Enable GitHub secret scanning (free for public repos, paid for private).
      Go to repo → Settings → Code security and analysis → Enable “Secret scanning”.

    • Step 5: Use cloud native tools like AWS Macie, Azure Purview, or GCP DLP to scan storage buckets for PII and credentials.

    What Undercode Say:

    • Key Takeaway 1: Traditional subdomain enumeration is insufficient; bug hunters must pivot to leaked APIs, Postman workspaces, and CT logs to find high‑impact vulnerabilities. Automated secret scanners (trufflehog, gitleaks) are non‑negotiable tools.

    • Key Takeaway 2: Defenders cannot rely on perimeter security alone. Continuous monitoring of public code repositories, cloud misconfigurations, and developer workspaces is essential. Implementing pre‑commit hooks and secret rotation policies reduces exposure by 90%.

    Analysis: The post by Deepak Saini highlights a paradigm shift in bug bounty hunting—from volume (many subdomains) to value (deeply hidden but critical assets). Attackers now spend more time on OSINT against GitHub, Postman, and cloud metadata than on brute‑forcing subdomains. Organizations that ignore these vectors suffer data breaches via “trivial” leaks: a single exposed API key in a public workspace can lead to account takeover. The provided GitHub repo (link in original post) likely aggregates these techniques into a practical toolkit, reflecting the community’s move toward automation and intelligence‑driven recon.

    Prediction: Within the next 18 months, automated AI‑driven agents will crawl GitHub, Postman, and Slack archives in real time, feeding directly into autonomous exploitation frameworks. This will force security teams to adopt “secrets zero‑trust”: every commit, every workspace, and every cloud bucket will be treated as potentially compromised. Bug bounty platforms will introduce dedicated categories for “Postman leakage” and “GitHub dorking,” with bounties rising for these overlooked findings. Simultaneously, we will see regulatory pressure (e.g., PCI DSS v4.0, ISO 27001:2025 updates) mandating automated secret scanning across all development pipelines.

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    Reported By: Deepak Saini – Hackers Feeds
    Extra Hub: Undercode MoN
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