The Logic Flaw That Leads to Total Control: Mastering Account Takeovers in 2026
This vulnerability falls under the Authentication Bypass class, specifically Logical Account Takeover. ZACK0X01's tutorial reveals that attackers can bypass multi-factor authentication (MFA) by exploiting subtle disconnects in authentication flows. The researcher manipulates responses and leverages Insecure Direct Object References (IDOR) to gain control of any user account. By observing patterns in error messages, the researcher found opportunities to intercept MFA codes or bypass MFA checks entirely. The critical severity (CVSS ~9.8) demonstrates the devastating impact: complete account takeover and unauthorized access to sensitive data. The tutorial offers actionable insights for finding this high-impact vulnerability class in web applications. Key lesson: Look beyond syntax errors, focus on business logic flaws to master account takeovers. #BugBounty #WebSecurity #AuthenticationBypass #IDOR #AccountTakeover
