A07: Authentication Failures

Authentication Failures occur when an application improperly implements authentication mechanisms, allowing attackers to compromise user accounts, bypass authentication, or exploit weak credentials. These vulnerabilities often result from weak password policies, missing multi-factor authentication (MFA), improper session management, or insecure credential storage, leading to unauthorized access, account takeovers, and data breaches. The OWASP Top 10:2025 shortened the name from Identification and Authentication Failures, but the scope is unchanged: proving who a user is, and keeping that proof valid only as long as it should be.

Common Vulnerabilities:

• Weak Password Policies (Allowing Short, Predictable, or Reused Passwords)
• Missing or Improperly Enforced Multi-Factor Authentication (MFA)
• Brute-Force or Credential Stuffing Due to Lack of Rate Limiting
• Username Enumeration Through Distinct Responses or Response Times
• Session Fixation or Session Hijacking Due to Poor Session Management
• Session Tokens That Never Expire or Are Not Rotated After Privilege Changes
• Exposed or Hardcoded Credentials in Source Code or Configuration Files
• Improperly Implemented Password Reset or Recovery Mechanisms Allowing Account Takeovers

To mitigate these risks, applications should enforce strong password policies, implement MFA for critical actions, use secure session management practices (e.g., regenerating session IDs after login), and protect stored credentials using strong hashing algorithms (bcrypt, Argon2, PBKDF2). Additionally, monitoring authentication logs for suspicious activity and implementing rate-limiting mechanisms can help prevent brute-force and automated attacks.