SQL Injection Authentication Bypass

Normal Authentication Flow

SELECT * FROM users WHERE username = 'admin' AND password = 'password'

The application:

• Takes username and password inputs
• Constructs SQL query with these values
• Authenticates if query returns user data
• Rejects if no results found

Authentication Bypass Attack

Attack Method

Input Values:

• Username: administrator'--
• Password: (blank)

Resulting Query:

SELECT * FROM users WHERE username = 'administrator'--' AND password = ' '

How It Works

1. The ' character closes the username string.
2. The -- comments out the rest of the query.
3. The password check is bypassed, allowing access to the admin account.

Security Implications

• No password required
• Access to any user account
• Complete authentication bypass
• Potential privilege escalation

Prevention Measures

1. Parameterized queries
2. Input validation
3. Escaping special characters
4. Strong authentication mechanisms
5. Multi-factor authentication