Unauthenticated

Focus: Identifying vulnerabilities in web applications and APIs that are accessible without requiring user login or authentication.

Why Unauthenticated Testing Matters:

• Large Attack Surface: Unauthenticated areas are often the first point of interaction for users and attackers.

• Direct Impact: Vulnerabilities here can often have immediate impact (information disclosure, DoS, etc.) without needing account compromise.

• Common Misconfigurations: Access control issues and logic flaws in public areas are frequently found.

Key Vulnerability Areas in Unauthenticated Contexts:

• Information Disclosure:

  • Accidental exposure of sensitive data in publicly accessible files (e.g., .git/config, backups).

  • Verbose error messages revealing internal paths, technologies, or configurations.

  • Publicly accessible directories listing files.

  • Source code comments or debugging information left in client-side code.

  • Leaking sensitive data via Referer header due to permissive Referrer-Policy.

• Unauthenticated Access to Sensitive Resources:

  • Bypassing intended access controls to reach administrative panels, internal APIs, or data intended for authorized users only.

  • Accessing sensitive files or directories not meant for public access.

• Business Logic Flaws in Public Workflows:

  • Exploiting logic errors in unauthenticated features (e.g., guest checkout, free trials, public forms, search functionality).

  • Bypassing rate limiting or abuse prevention mechanisms in public APIs or features.

  • Parameter manipulation in public forms to gain unintended access or functionality.

• Cross-Origin Resource Sharing (CORS) Misconfigurations:

  • Overly permissive CORS policies allowing unauthorized cross-domain access to sensitive APIs or data, potentially leading to data theft or account takeover.

  • Exploiting wildcard (*) origins or null origin issues in CORS headers.

• Server-Side Vulnerabilities (Unauthenticated Exploitation):

  • Server-Side Request Forgery (SSRF) exploitable without authentication.

  • Command Injection, Path Traversal, or other injection vulnerabilities that can be triggered in unauthenticated areas.

  • Denial of Service (DoS) vulnerabilities in publicly accessible features.

  • Vulnerabilities in third-party components or libraries used in unauthenticated functionalities.

Unauthenticated Testing Steps & Methodology:

1. Reconnaissance & Attack Surface Mapping (Initial - Automated):

   • Tool: httpx (or naabu for subdomain enumeration if needed)

   • Purpose: Quickly discover live domains/paths, gather basic information (status codes, headers, server info).

   • Command Example: httpx -l target_list_168.txt -json -retries 1 -timeout 3 -follow-redirects -status-code -headers -server-header -output initial_recon.json

2. Content Discovery (Unauthenticated Paths & Files):

   • Tools: ffuf, dirsearch, gobuster

   • Purpose: Brute-force for hidden directories, files, and endpoints that might be publicly accessible but not linked or obvious.

   • Wordlists: Use common web wordlists (e.g., SecLists, dirbuster).

   • Targeted Fuzzing: Focus on common admin paths, backup extensions, and sensitive file names (e.g., .env, .git, config.php, admin/, api/v1/).

   • Example (ffuf): ffuf -w path_wordlist.txt -u TARGET_URL/FUZZ -fs <filesize_of_404_page> -o content_discovery.txt (Filter out common 404 responses to reduce noise)

3. Parameter Fuzzing & Manipulation (Unauthenticated Endpoints):

   • Tools: ffuf, Burp Intruder

   • Purpose: Identify vulnerabilities by manipulating URL parameters, headers, and request bodies in publicly accessible endpoints.

   • Fuzzing Payloads: Use common web vulnerability payloads (e.g., XSS, SQLi, command injection, path traversal - but focus on unauthenticated context).

   • Parameter Tampering: Experiment with modifying parameters to bypass logic, access different data, or trigger errors.

   • API Testing: Focus on unauthenticated API endpoints. Test for:

     • Information Disclosure: Do API responses reveal more data than intended without authentication?

     • Mass Assignment: Can you manipulate request parameters to modify data you shouldn't be able to?

     • Rate Limiting Issues: Can you abuse public APIs due to lack of rate limiting?

     • Input Validation Flaws: Fuzz API parameters for injection vulnerabilities.

4. Business Logic Testing (Unauthenticated Features):

   • Tools: Browser, Burp Proxy, Manual Analysis

   • Purpose: Identify flaws in the application's logic within publicly accessible workflows.

   • Analyze Public Features: Thoroughly test guest features, signup/registration processes, public forms, search functions, contact forms, etc.

   • Look for Logic Flaws: Can you bypass steps, manipulate quantities, get free access to paid features, abuse public forms for spam or unintended actions?

   • Example: Test guest checkout workflows for price manipulation, coupon abuse, or ability to access order details without login.

5. CORS Misconfiguration Testing:

   • Tools: Browser Developer Tools, curl

   • Purpose: Identify and exploit Cross-Origin Resource Sharing (CORS) vulnerabilities.

   • Inspect CORS Headers: Examine Access-Control-Allow-Origin, Access-Control-Allow-Methods, Access-Control-Allow-Credentials headers in responses.

   • Test with Different Origins: Try to access resources from different origins (attacker-controlled domain) using JavaScript (fetch or XMLHttpRequest) to see if CORS policies are correctly enforced.

   • Look for: Wildcard Origins (*), null origin issues, insecure use of Access-Control-Allow-Credentials: true.

6. Error Message Analysis:

   • Tools: Browser, Burp Proxy, Manual Review

   • Purpose: Carefully analyze error messages for information leakage.

   • Trigger Errors: Intentionally cause errors by providing invalid input, manipulating requests, etc., in unauthenticated areas.

   • Look for: Stack traces, internal paths, database errors, technology/version disclosure in error messages.

7. Source Code Review (If Publicly Available):

   • Tools: Browser Dev Tools (for client-side code), curl or wget (to download publicly accessible code repositories if found - e.g., .git/, .svn/)

   • Purpose: Analyze client-side code (JavaScript, HTML, CSS) and server-side code (if accidentally exposed) for vulnerabilities and sensitive information.

   • Look for: Hardcoded API keys, secrets, comments revealing logic flaws, insecure client-side handling of data, exposed API endpoints in JavaScript, etc.

Key Things to Look For (Red Flags in Unauthenticated Testing):

• Unexpected HTTP Status Codes: 403 Forbidden, 401 Unauthorized, 500 Internal Server Error on publicly accessible paths.

• Verbose Error Messages: Revealing internal details.

• Directory Listings Enabled: Publicly accessible directories showing file structures.

• Sensitive Data in Source Code Comments: Or client-side code.

• Overly Permissive CORS Headers: Wildcard origins, null origin allowed.

• Lack of Rate Limiting: On public APIs or features.

• Logic Flaws: In guest workflows or public forms.

• Default Credentials: (Though less common in "unauthenticated" context, still worth a check on login pages if found during content discovery).

Remember:

• Focus on publicly accessible areas first.

• Automate initial reconnaissance to cover the large attack surface efficiently.

• Prioritize targets and findings based on potential impact.

• Document your steps and findings clearly.