In 2024, attackers breached over 160 Snowflake customer environments (AT&T, Ticketmaster, and more)—all thanks to missing access validations. Billions of records exposed. That's the real-world cost of broken access control—OWASP's top-ranked flaw.
Broken access control isn't just a technical flaw, it is a serious business threat. Left unresolved, Broken Access Control can lead to data breaches, privilege escalation, regulatory violations, and even full system compromise.
What is Broken Access Control?
Broken access control occurs when your application allows users or attackers to perform actions beyond their intended permissions. These failures often stem from unchecked endpoints, insecure logic, or misconfigured access checks.
Access control involves:
- Authentication – Confirming identity
- Session management – Secure tracking of sessions
- Authorization – Enforcing user privileges
- Access enforcement – Actually blocking or allowing actions server-side
- Audit & management – Binding role assignments, logging behavior
Broken access control occurs when these restrictions fail—allowing unauthorized users to access or modify sensitive data and functionalities.
Broken Access Control vs Secure Access Control
Why is Broken Access Control the #1 Risk on OWASP Top 10?
According to OWASP, 94% of applications were found to have some form of broken access control, with an average incidence rate of 3.81% per application. Here's why it's so prevalent:
- Explosion in digital services – More apps mean more potential vulnerabilities
- Interconnected systems – Increased integration between applications expands the attack surface
- Weak DevSecOps practices – Developers often lack adequate security training
- Fragmented IAM solutions – Disparate identity management tools can create access loopholes
Notable Broken Access Control Breaches (2024–2025)
Snowflake Data Breach (Mid-2024)
Attackers exploited weak credential management, accessing over 160 customer environments including AT&T and Ticketmaster. Billions of records were compromised, underscoring the importance of robust access enforcement.
Airportr (UK Luggage Service) Breach (July 2025)
Researchers found flaws like insecure password resets and lack of rate limiting, leading to admin account takeover. Personal travel data, including passport scans, was exposed.
Microsoft SharePoint Zero-Day (July 2025)
Chinese threat actors bypassed access controls in SharePoint to access global government data. Despite patches, the breach impacted over 400 institutions.
Qantas/Third-Party Help Desk Breach (June 2025)
Social engineering attacks on third-party systems bypassed internal access control, exposing data from over 6 million customers.
Common Root Causes of Broken Access Control
Consequences of a Broken Access Control Breach
The dangers of broken access control go far beyond technical inconvenience:
- Data breaches – Sensitive information exposed to unauthorized users.
- Regulatory non-compliance – Violations can result in legal and financial penalties.
- Operational disruption – Privilege escalation can paralyze or sabotage business operations.
How to Build Secure Access Control
1. Deny by default: Unless explicitly allowed, block access. All endpoints must check authorization server-side.
2. Implement function-level role based access control (RBAC): Use centralized role checks at the handler layer or middleware for every API and UI action.
3. Use parameter binding and whitelisting: Disallow clients from assigning sensitive fields (like role, isAdmin) in JSON or form data.
4. Harden session & CSRF: Every state-changing endpoint must validate CSRF tokens. Don't rely on hidden referrer headers.
5. Controlled CORS and cross-origin logic: Limit Access-Control-Allow-Origin, disable insecure cross-site access flows.
6. Automate access testing:
- Static App Security Testing (SAST): enforce annotations on access logic.
- Dynamic App Security Testing (DAST): test IDOR paths via proxy.
- Manual pen testing & fuzzing: target endpoints with manipulated IDs and headers.
7. Audit & log everything: Logs should capture user ID, endpoint, role, requested resource, decision outcome (allowed/denied).
8. Third-party vetting: Don't trust vendor modules or APIs to enforce your access policies—validate calls at your service boundary.
Final Thoughts
This isn't a checkbox issue, it's embedded in your application's design, logic, and access architecture. Broken access control is a gap that attackers can drive an entire truck through. If you're building or securing applications, make every request count. Enforce checks at every layer and continuously test.
Breaking access control might be easy—but fixing it proactively is what separates secure systems from breach headlines.
Rakuten's Commitment to Zero Breaches
At Rakuten, we're on a mission to help you build systems that are immune to access-related vulnerabilities. We don't believe in quick patches—we believe in long-term prevention.
Start protecting your API ecosystem from day one—try Rakuten Security for free today.