last posts

Are business logic flaws putting your APIs at risk?


Short answer – yes. Most application programming interface (API) attacks aren’t the usual type of password cracking or injection.

A good example is the recent Facebook hack, which exposed tens of millions of user data. In this case, the API logic enabled the exploit and the attacker took advantage of it. This was an unauthorized use of the API.

Attackers don’t need to hack the API. They uncover inherent business logic issues and exploit vulnerabilities like BOLA.

Are you vulnerable to business logic flaws? How can you mitigate the vulnerability with API Security? Keep reading to find out.

What are business logic flaws?

Business logic flaws are flaws in API design and implementation. They allow attackers to manipulate legitimate data, workflows, and functionality to achieve their malicious goals. These malicious goals can range from privilege escalation to disposal to account takeovers.

Business logic flaws are different from other web security vulnerabilities. What sets them apart? They are invisible to automated analysis tools.

Logic flaws are context-specific and often different from organization to organization. These flaws are also invisible to security testers unless they look for them explicitly. Attackers exploit legitimate processing features/flows to achieve malicious end goals.

Why are business logic flaws prime targets for API hackers?

Organizations often overlook flaws in business logic. They hadn’t anticipated unusual user interactions with the API/application. They may not see how users can abuse legitimate processes. Therefore, attackers can easily exploit the API/application.

Also, attackers don’t have to steal credentials and API keys or buy them on the black market. They don’t have to crack passwords or engage in tech hacking. They just have to abuse the logic to manipulate the API.

The API, unable to detect malicious behavior, will respond in the way it was designed to. And that way, attackers can seamlessly bypass systems to do whatever they want.

Attack vectors for business logic flaws:

  • Do not handle unconventional entries
  • Over-reliance on client-side control
  • Wrong assumptions about user behavior
  • Authorization Bypass
  • Misuse of HTML elements
  • Defects specific to the domain of the company – for example, the abuse of the discount functionality

How to manage business logic vulnerabilities in APIs

Company-specific knowledge is required

Often, attackers know how APIs work, their business logic, and the business operations they affect. They also tend to have a better understanding of how business logic works in complex APIs. Even better than the developers.

Start with the basics to ensure better API security. Understand the domain and details of the company served by the API. You need to be up to date with the changing API threat landscape.

Think Beyond the Left Shift

There has been a paradigm shift in favor of the leftist approach to security. This approach requires organizations to integrate security from the earliest stages of development.

Business logic flaws are hard to find by analyzing static code in pre-deployment stages. Unless the API is in action, you cannot find logic flaws. Security should be continuous and align your product, processes and people with security.

Security scanners cannot detect logical flaws

Relying solely on detecting misconfigurations, access control flaws, or known vulnerabilities is not enough. Application security scanning tools suffer from the same issues.

Security scanners are designed to find weak development practices and application security vulnerabilities. They miss most business logic flaws and API-related misconfigurations.

Take a holistic view of API security

Treat API security as a separate discipline and add best practices to avoid potential mistakes that often lead to attacks.

It is essential to take a comprehensive approach API security solutions like AppTrana to analyze, protect and provide adequate context for APIs. Core features include API discovery, API security testing, OWASP Top 10 API security, positive security policy, and API-specific rules.

Each company is unique and allows for unique business logic. Therefore, the tool should be fast enough to construct client rules accordingly. This requires an understanding of the business context and the underlying risks.

Attack Simulation

The final piece of the puzzle is detecting real-time attacks against your APIs and endpoints. The API security tool should complement the experts for three reasons.

  1. Find current vulnerabilities you didn’t know about
  2. Help you understand what logic flaws exist and how exploitable they are
  3. Eliminate false positives before you start initiating remediation actions

Create test cases that cover all possible attack scenarios. The more scenarios you test, the more likely you are to find inherent logic flaws


Business logic flaws in APIs can be exploited in minutes of trial and error. Take proactive steps to secure your business logic vulnerabilities. This helps close the gaps in your API security policies.



Font Size
lines height