OAuth State Bypass Scanner
Detects missing or weak OAuth state parameter validation.
What is OAuth State Bypass?
OAuth State Bypass attacks exploit missing or weak state parameter validation, enabling Cross-Site Request Forgery (CSRF) against OAuth flows. Without proper state validation, attackers can force victims to authenticate with the attacker's account or link the attacker's identity to the victim's session.
Why is This Important?
State parameter vulnerabilities enable account takeover scenarios. Attackers can link their social login to a victim's account, force victims into attacker-controlled sessions, or steal sensitive data by having victims authenticate to attacker accounts. These attacks are often invisible to victims.
How It Works
1. Auth Flow Analysis
Maps authentication mechanisms including login, registration, password reset, and session management flows.
2. Security Testing
Tests for authentication bypasses, weak credentials, session flaws, and token vulnerabilities.
3. Access Verification
Validates findings by demonstrating unauthorized access or privilege escalation paths.
Key Capabilities
Comprehensive authentication security testing to protect user accounts and prevent unauthorized access.
- Complete authentication flow analysis
- Token and session security validation
- Password policy and brute-force testing
- Multi-factor authentication bypass detection
- OAuth, SAML, and JWT security assessment
Frequently Asked Questions
What is the OAuth state parameter for?
The state parameter is a CSRF token. The client generates a random value, includes it in the authorization request, and verifies the same value returns in the callback. This ensures the callback is a response to a request the client initiated, not an attacker's injection.
What attacks are possible without state validation?
Login CSRF: force victim to log in as attacker. Account linking attacks: link attacker's social account to victim's profile. Session fixation: trap victim in attacker's session. Token theft: in some flows, intercept victim's tokens for attacker's use.
What makes a state parameter weak?
Weak states include: predictable values, short random strings, reused values, values not tied to the user's session, and client-side only validation. State should be unpredictable, single-use, tied to the session, and validated server-side.
How do I implement state correctly?
Generate cryptographically random state values (128+ bits), store in server-side session or signed cookie before redirect, validate exact match on callback, use state only once then delete, consider including timestamp for expiration, and always require state parameter.
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