Broken Authentication Testing

Purpose

Identify and exploit authentication and session management vulnerabilities in web applications. Broken authentication consistently ranks in the OWASP Top 10 and can lead to account takeover, identity theft, and unauthorized access to sensitive systems. This skill covers testing methodologies for password policies, session handling, multi-factor authentication, and credential management.

Prerequisites

Required Knowledge

• HTTP protocol and session mechanisms
• Authentication types (SFA, 2FA, MFA)
• Cookie and token handling
• Common authentication frameworks

Required Tools

• Burp Suite Professional or Community
• Hydra or similar brute-force tools
• Custom wordlists for credential testing
• Browser developer tools

Required Access

• Target application URL
• Test account credentials
• Written authorization for testing

Outputs and Deliverables

1. Authentication Assessment Report - Document all identified vulnerabilities
2. Credential Testing Results - Brute-force and dictionary attack outcomes
3. Session Security Analysis - Token randomness and timeout evaluation
4. Remediation Recommendations - Security hardening guidance

Core Workflow

Phase 1: Authentication Mechanism Analysis

Understand the application's authentication architecture:

# Identify authentication type
- Password-based (forms, basic auth, digest)
- Token-based (JWT, OAuth, API keys)
- Certificate-based (mutual TLS)
- Multi-factor (SMS, TOTP, hardware tokens)

# Map authentication endpoints
/login, /signin, /authenticate
/register, /signup
/forgot-password, /reset-password
/logout, /signout
/api/auth/*, /oauth/*

Capture and analyze authentication requests:

POST /login HTTP/1.1
Host: target.com
Content-Type: application/x-www-form-urlencoded

username=test&password=test123

Phase 2: Password Policy Testing

Evaluate password requirements and enforcement: