The OWASP API Security Top Ten: API1:2019 Broken Object Level Authorization

The OWASP API Security Top Ten, a key initiative by the international non-profit OWASP, aims to highlight the most significant risks to web applications, focusing particularly on APIs. The 2019 list identifies "Broken Object Level Authorization" as the top vulnerability, where unauthorized access to sensitive data can occur due to insufficient authorization checks in RESTful APIs. This issue arises when APIs, unlike monolithic applications, lack native session management, making it easier for malicious actors to manipulate parameters and access restricted data. To mitigate this risk, it is recommended to implement robust authorization mechanisms that verify user permissions for every action, use random and unpredictable IDs to prevent unauthorized access, and conduct rigorous testing to ensure these security measures are effective. The blog series plans to expand on each listed vulnerability, with the next topic being "Broken User Authentication."