Broken Authentication Challenges
OWASP A07:2021 - Identification and Authentication Failures
Authentication vulnerabilities allow attackers to compromise passwords, keys, or session tokens, or exploit implementation flaws to assume other users' identities.
Authentication vulnerabilities allow attackers to compromise passwords, keys, or session tokens, or exploit implementation flaws to assume other users' identities.
Beginner
Weak Passwords
Exploit weak password policies and missing brute-force protection to gain access to user accounts using common passwords.
- Points: 100
- Estimated Time: 15 minutes
- Skills: Dictionary attacks, password guessing
Easy
Session Hijacking
Exploit predictable session IDs and missing session validation to hijack another user's authenticated session.
- Points: 150
- Estimated Time: 20 minutes
- Skills: Session prediction, enumeration
Medium
Password Reset Bypass
Exploit insecure password reset functionality through weak security questions and predictable reset tokens.
- Points: 200
- Estimated Time: 25 minutes
- Skills: Token prediction, social engineering
Learning Resources
Common Authentication Vulnerabilities
- Weak Passwords: Users choosing simple, guessable passwords
- Missing Brute Force Protection: No rate limiting or account lockout
- Predictable Session IDs: Sequential or easily guessable tokens
- Session Fixation: Accepting user-provided session identifiers
- Insecure Password Reset: Weak security questions, predictable tokens
- Credential Stuffing: Using breached credentials from other sites
Prevention Techniques
- Strong Password Policies: Minimum length, complexity, breached password checks
- Multi-Factor Authentication (MFA): Additional verification beyond passwords
- Rate Limiting: Limit login attempts, implement exponential backoff
- Secure Session Management: Random, high-entropy session IDs
- Session Binding: Tie sessions to IP/User-Agent, regenerate on privilege change
- Secure Password Reset: Time-limited tokens, out-of-band verification