> For the complete documentation index, see [llms.txt](https://www.christiandussol.dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.christiandussol.dev/cloud-ai-security/security/api-security-reality-check.md). # API Security Reality Check ## What years of securing financial APIs taught me You can spend weeks implementing zero-trust architecture, then deploy an API that exposes customer data through a simple ID manipulation. It is like installing a titanium front door and leaving all the windows open. This piece came out of a proactive security review on a financial product, where the classic API1 pattern turned up: URL parameter manipulation leading to unauthorized data access. Not exotic. Not sophisticated. Just the vulnerability that sits at number one on the OWASP list, year after year, because it keeps working.
### 📎 Visual companion [OWASP API Security Top 10 carousel (PDF)](https://github.com/christian-dussol-cloud-native/cloud-security/blob/main/carousel/OWASP%20API%20Security%20Top%2010%20Print.pdf) ### What the article covers * The 4C model (Code, Container, Cluster, Cloud) and why an API vulnerability never stays at one layer. The domino effect from a forgotten authorization check to a cloud storage breach * The critical five, with real financial services impact: Broken Object Level Authorization, Broken Authentication, Broken Object Property Level Authorization, Unrestricted Resource Consumption, Broken Function Level Authorization * Why the critical three (API1, API2, API5) are where you start, and what changes once you have them under control * Kyverno as the prevention layer: how policy-as-code blocks the misconfiguration before it reaches the cluster, rather than catching it in a post-deployment scan * A 30-day plan, from audit to enforcement mode, that survived contact with real teams ### Read * **Medium article**: [API Security Reality Check: What Years of Securing Financial APIs Taught Me](https://medium.com/@christian.dussol/api-security-reality-check-what-years-of-securing-financial-apis-taught-me-1868bd95a893)