Earn Bounty by just Reading.

Companies often unintentionally expose files or documents on their public-facing servers, websites, or third-party services (e.g., GitHub, cloud storage like AWS S3 buckets, etc.). These files might include configuration files, source code, PDFs, text files, or other documents that contain information useful for identifying vulnerabilities. By carefully analyzing these, you can uncover issues like:

Sensitive Data Exposure: API keys, credentials, or personally identifiable information (PII).Misconfigurations: Improperly secured servers or services.Hidden Endpoints: Undocumented APIs or internal URLs.Business Logic Flaws: Insights into how the application works that could lead to exploitation.Outdated Software: References to old libraries or systems with known vulnerabilities.

This method is particularly effective because it leverages publicly accessible information, which is often within the scope of bug bounty programs, provided you don’t exploit or access anything beyond what’s allowed.

1. Find Exposed Files and Documents

To start, you need to locate files or documents that the company has made publicly available, either intentionally or by mistake. Here’s how:

Google Dorking: Use advanced search queries to find files. Examples:site:*.target.com filetype:pdfsite:target.com inurl:(config | backup | admin)site:target.com -inurl:(login | signup) (to filter out common pages).Wayback Machine: Check the Internet Archive (archive.org) for historical versions of the site that might expose old files.Subdomain Enumeration: Tools like Subfinder or Amass can reveal subdomains hosting files (e.g., files.target.com).Directory Brute-Forcing: Use tools like dirb, gobuster, or ffuf to find directories with exposed files (e.g., /config, /backup, /docs).GitHub Recon: Search for repositories related to the company using keywords like target.com, and look for leaked files or code.X Posts and Forums: Search X or hacker forums for mentions of the target where others might have shared findings (but verify independently).

2. Identify File Types to Analyze

Focus on file types that are likely to contain useful information:

Configuration Files: .env, .conf, .ini, .xml, .json (e.g., database credentials, API keys).Source Code: .js, .php, .py, .html (e.g., JavaScript files with endpoints or secrets).Documents: .pdf, .docx, .txt (e.g., manuals, employee guides, or architecture docs).Logs: .log (e.g., error logs with stack traces or sensitive data).Backups: .bak, .zip, .tar.gz (e.g., old database dumps or configs).

3. Analyze the Content

Once you’ve gathered files, read them carefully to spot vulnerabilities. Here’s what to search for and why it’s valuable:

Credentials and Secrets:Look for: api_key, password, secret, token, aws_access_key, private_key, etc.Why: Exposed credentials can lead to unauthorized access (e.g., broken authentication or access control issues).Example: A .env file with DB_PASSWORD=supersecret123 could be a reportable finding.Endpoints and URLs:Look for: http://, https://, /api/, endpoint=, url=.Why: Hidden or undocumented endpoints might be vulnerable to attacks like SQL injection, XSS, or IDOR (Insecure Direct Object Reference).Example: A JavaScript file revealing /api/v1/userdata?id=123 could be tested for IDOR.Error Messages or Stack Traces:Look for: exception, error, traceback, SQL queries, or file paths.Why: These can reveal backend technologies, misconfigurations, or injection points.Example: A log file showing SELECT * FROM users WHERE id = ‘1’ might indicate SQL injection potential.Version Information:Look for: References to software versions (e.g., Apache 2.4.29, jQuery 1.8.3).Why: Outdated versions may have known CVEs (Common Vulnerabilities and Exposures) you can report.Example: A PDF mentioning “Powered by OpenSSL 1.0.1” could point to a version with known exploits.Sensitive Data:Look for: PII (names, emails, SSNs), financial data, or internal IPs.Why: Exposure of sensitive data is often a valid bug bounty finding.Example: A misconfigured S3 bucket with a .csv of customer emails is reportable.Business Logic Clues:Look for: Descriptions of workflows, user roles, or permissions.Why: Understanding the app’s logic can help you find flaws like privilege escalation.Example: A manual stating “Admins can approve via /admin/approve” might reveal an unprotected endpoint.

4. Tools to Assist Analysis

Text Search: Use grep or findstr to search files efficiently:grep -r “api_key” /path/to/filesgrep -r “password” *.jsCode Review Tools: Use Sublime Text, VS Code, or Notepad++ with regex search for keywords.Deobfuscation: If JavaScript is obfuscated, use online tools like jsbeautifier.org to make it readable.PDF/Text Extraction: Use pdftotext or catdoc to extract text from PDFs or Word docs.Automation: Tools like truffleHog or GitLeaks can scan for secrets in files or repositories.

5. Validate and Test Findings

Don’t just report raw data — test it within the program’s scope:If you find an API key, check if it’s active and what it accesses.If you find an endpoint, test it for common vulnerabilities (e.g., XSS, SQLi, IDOR).If you find sensitive data, confirm it’s not a honeypot or intentional bait.Use tools like Burp Suite or Postman to interact with endpoints safely.

6. Write a Report

Submit a clear, detailed report to the bug bounty program:

Title: E.g., “Exposed API Key in Public Config File”Description: Explain what you found and its potential impact.Steps to Reproduce: List how you accessed the file and what you discovered.Proof: Include screenshots or snippets (redact sensitive data if required).Impact: Highlight risks (e.g., data breach, account takeover).Mitigation: Suggest fixes (e.g., remove the file, rotate keys).

When analyzing files and documents, prioritize these common weak spots:

Hardcoded Credentials: Keys or passwords embedded in code or configs.Unprotected Endpoints: APIs or admin panels without authentication.Misconfigured Permissions: Files accessible to anyone due to poor server settings.Outdated Tech: References to old software with known exploits.Data Leakage: Unintended exposure of PII or internal info.

Bug bounty programs reward findings based on severity and impact. Here’s how your discoveries might pay off:

Low Severity ($50-$500): Exposed non-critical data or outdated software versions.Medium Severity ($500-$2,000): Leaked API keys or unprotected endpoints with limited access.High/Critical Severity ($2,000-$10,000+): Active credentials leading to account takeover, sensitive data breaches, or remote code execution.

For example, finding a public .env file with a database password that grants access to customer data could net you a high payout, as it’s a critical issue.

Stay in Scope: Only analyze files within the program’s defined boundaries (e.g., *.target.com).Be Ethical: Don’t exploit beyond proving the vulnerability exists.Start Small: Target programs with broad scopes (e.g., wildcards like *.example.com) to find more exposed files.Learn from Others: Read public bug bounty write-ups (e.g., on HackerOne or Medium) to see how others leverage file analysis.

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