Missing Function Level Access Control is a significant vulnerability identified by OWASP, which occurs when authentication checks in request handlers are inadequate, allowing unauthorized users to access sensitive URLs or functionalities intended for authorized users. This vulnerability is part of OWASP's Top 10 list and has become increasingly common since its initial identification as uncommon in 2010. The potential impact ranges from accessing seemingly trivial information to full system takeover, with exploitation often being straightforward, as it might involve simply performing actions that should require authentication. The Twitter vulnerability is a notable example, where a user altered request parameters to delete another user's account, showcasing the real-world implications of such vulnerabilities. Detectify offers a web security scanner to identify over 700 vulnerabilities, including those highlighted by OWASP, providing a systematic approach to discovering and mitigating Missing Function Level Access Control issues. Remediation involves implementing a default denial strategy, logging failed access attempts, and avoiding reliance on security through obscurity, as users may discover hidden URLs or APIs.