What problem does it solve? MFA implementations often contain logic flaws—missing rate limits, reusable OTPs, client-side-only checks, and workflow skips—that let attackers reach post-authentication state without a valid second factor. This Skill gives security testers a structured checklist of seven distinct MFA bypass patterns with concrete test procedures so no common bypass class is missed during an authorized engagement. ## Core Features & Use Cases - Seven Bypass Patterns: Covers OTP brute-force without rate limiting, OTP replay after use, response manipulation, MFA-step skip via direct navigation, race conditions on OTP validation, backup-code brute force, and remember-device trust escalation. - Ready-to-Run Test Procedures: Includes ffuf commands for OTP fuzzing, Burp-based response manipulation steps, and an aiohttp race-condition script. - Chain Escalation Guidance: Maps each primitive to severity outcomes and links to related skills (hunt-ato, hunt-race-condition, hunt-auth-bypass) for chaining MFA bypass into full account takeover. - Use Case: During a bug bounty hunt on a web app, trace the login flow in Burp, identify whether MFA is middleware-gated or per-endpoint, then systematically test each pattern—e.g., replaying a used OTP or skipping the /mfa route with a pre-MFA cookie—to confirm a Critical auth-flow bypass. ## Quick Start Ask the agent to test the target's MFA flow for bypass using the seven patterns, starting with OTP rate-limit and replay checks against the verify endpoint.
