Website Pentesting: User Credentials?

TL;DR

Not always! Many types of website pentesting don’t *require* a userid and password. It depends on what you’re testing for. We’ll cover when you need them, and when you can get useful results without.

Understanding Pentesting Types

First, let’s quickly look at the main types of pentesting. This helps explain if credentials are needed:

• Black Box Testing: You know nothing about the website’s internals. Like a real attacker, you try to find vulnerabilities from scratch. Credentials aren’t usually provided initially.
• Grey Box Testing: You have *some* information (e.g., user roles, documentation). Sometimes credentials are given for specific accounts.
• White Box Testing: You have full access – source code, database details, and often admin credentials.

When User Credentials ARE Needed

You’ll almost certainly need userid/password combinations when testing:

1. Authentication & Authorisation Flaws: This is the big one! Testing if users can log in with weak passwords, bypass multi-factor authentication (MFA), or access accounts they shouldn’t.
2. Session Management Issues: Checking how sessions are handled – can you hijack someone else’s session?
3. Account Takeover Vulnerabilities: Trying to gain control of legitimate user accounts.
4. Privilege Escalation: Can a standard user account access admin functions?

In these cases, you’ll need valid accounts. These might be:

• Accounts provided by the website owner (ideal).
• Test accounts created specifically for pentesting.
• (With permission!) Accounts created using publicly available information – but *always* get explicit consent first!

When User Credentials AREN’T Needed

You can perform valuable pentesting without logging in:

1. Cross-Site Scripting (XSS): Injecting malicious scripts into the website to see if they execute in other users’ browsers.
2. SQL Injection: Exploiting vulnerabilities in database queries, often through input fields like search boxes or forms.
3. Broken Access Control (without login): Can you access sensitive pages directly by manipulating URLs? For example:

   https://example.com/admin/panel

4. Server-Side Request Forgery (SSRF): Making the server make requests to internal resources.
5. Denial of Service (DoS) & Distributed Denial of Service (DDoS): Overwhelming the website with traffic.
6. Information Disclosure: Finding sensitive data exposed in error messages, comments, or source code.

Tools like Burp Suite and OWASP ZAP can help with these tests without needing credentials.

Practical Steps

1. Define the Scope: What parts of the website are you allowed to test? This is *crucial*.
2. Gather Information (Reconnaissance): Use tools like whois and nslookup to find details about the domain.

whois example.com

3. Identify Potential Vulnerabilities: Scan for open ports, common web vulnerabilities using automated scanners (but *always* manually verify results!).
4. Test Without Credentials First: Start with black box techniques – XSS, SQL injection, broken access control.
5. If Needed, Request Accounts: If you need to test authentication, ask the website owner for appropriate accounts.
6. Document Everything: Keep detailed records of your tests and findings.

Important Considerations

• Permission is Key: Never pentest a website without explicit written permission from the owner. It’s illegal otherwise!
• Stay Within Scope: Don’t test areas you haven’t been authorized to access.
• Report Findings Responsibly: Provide clear, actionable reports to the website owner so they can fix vulnerabilities.