Authentication Vulnerabilities | Web Security Academy

Introduction to Authentication Vulnerabilities

• Critical due to the relationship between authentication and security.
• Can allow attackers access to sensitive data and additional attack surfaces.
• Importance of identifying, exploiting, and bypassing common authentication vulnerabilities.

Key Topics Covered

• Common authentication mechanisms used by websites.
• Potential vulnerabilities in these mechanisms.
• Inherent vulnerabilities in different authentication methods.
• Typical vulnerabilities from improper implementation.
• How to create robust authentication mechanisms.

Labs

• Practicing exploiting authentication vulnerabilities on deliberately vulnerable targets.
• Access labs here.

What is Authentication?

• Process of verifying the identity of a user or client.
• Essential for web security exposed to internet users.
• Three main types of authentication:
  • Something you know: password or security question (knowledge factors).
  • Something you have: mobile phone or security token (possession factors).
  • Something you are: biometrics or behavior patterns (inherence factors).

Distinction Between Authentication and Authorization

• Authentication: verifies user identity (e.g., Carlos123).
• Authorization: verifies user permissions (what actions user can perform).

How Authentication Vulnerabilities Arise

• Weak authentication mechanisms not protecting against brute-force attacks.
• Logic flaws or poor coding allowing bypassing (known as "broken authentication").
• Logic flaws may lead to unexpected website behavior, exposing security issues.

Impact of Vulnerable Authentication

• Severe consequences if authentication is bypassed.
• Access to data and functionality of compromised accounts.
• High-privilege account compromise can lead to full application control.
• Even low-privilege accounts can expose sensitive information or increase attack surface.

Common Vulnerabilities in Authentication Mechanisms

• Vulnerabilities may occur in multiple distinct authentication mechanisms:
  • Password-based login vulnerabilities LABS
  • Multi-factor authentication vulnerabilities LABS
  • Other authentication mechanisms vulnerabilities LABS

Additional Resources

• Shortlist of candidate usernames and passwords for lab exercises.
• OAuth authentication labs available for those interested in hacking authentication mechanisms.

Preventing Attacks on Authentication Mechanisms

• Follow principles to reduce risk of attacks on your own authentication implementations.