πŸ”

Understanding Authentication Vulnerabilities in Web Security

Mar 18, 2025

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.

Authentication vulnerabilities: password reset poisoning

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

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.