Business logic vulnerabilities often go undetected for years. Nothing makes cybercriminals happier than an application with vulnerabilities they can exploit without any special tools—simply working within the normal functionality of the app.

Since most vulnerabilities are exposed in the development phase, catching them during the design phase will require new strategies beyond what has been the industry norm.

“Without proper testing, you’re leaving those APIs exposed and just ripe for the picking.”

- Corey Ball, Cybersecurity Consulting Manager & Author of "Hacking APIs"

We’ve identified common business logic flaws and provided our top tips for eliminating them during application design.

1. Ensure Proper Authorization and Authentication Measures From Day 1

Attackers often gain access to sensitive data through vulnerabilities in authentication and authorization resources that they should not have access to. Here are the most common business logic flaws associated with this cluster of API threats and how you address them from the start:

• Unprotected APIs: Implement stringent authorization and authentication for all internal and staging APIs so they can’t be compromised to pivot to other systems.
• Weak credential policy: Restrict the use of insecure or previously exposed passwords to guard yourself against automated brute force attacks.
• Flawed credential recovery process: Ensure that permit recovery or credential reset can’t be triggered with insufficient information.
• Broken authentication: Make it impossible to view, modify, or remove the data of another account without the corresponding user privileges.

Read More: API Security Checklist: What You Need To Know

2. Eliminate Data Input And Client-Side Loopholes

Malicious attackers can alter a database query without using any exploits to make the application execute unauthorized commands. To combat this, we recommend evaluating the most common business logic flaws related to data input and client-side vulnerabilities.

• Critical parameter manipulation: Inspect HTTP request parameters (the values sent in the request body) to make it impossible to tamper them to query the database.
• Cookie tampering: Encrypt session and cookie data to prevent the attacker from reverse engineering business logic and modifying cookie parameters to launch a privilege escalation attack.
• LDAP injection attacks: Check LDAP parameters for any business logic flags to prevent bad actors from changing them to bypass the business layer.
• Client-side vulnerabilities: Examine your business routines embedded in JavaScript, Flash, or other client-side languages.

Read More: Drilling Down Into Excessive Data Exposure: How to Protect Your APIs Sensitive Data

3. Eliminate Logic Flaws From Processes and Workflows

When application workflows or processes have design flaws built into the business logic, users short-circuit them in unintended ways to bypass security checks and gain unauthorized access to data and functionalities.

That’s why it's essential to meticulously test every action and task the user can perform to uncover potential loopholes. These business logic vulnerabilities would be a great starting point:

• Business constraint exploitation: Ensure that no hidden user fields contain values that control the constraints or restrictions defined by the business logic layer.
• Business flow bypass: Break down your application workflows to verify steps can’t be hijacked, skipped, or bypassed to perform a certain task.
• Denial of Services (DoS) with business logic: Check for the possibility of short-circuiting processes with infinite loops to overload or crash the system.
• Auto-increment IDs: Graduate from using automatically-incrementing identifiers when generating database records to make it impossible for the attacker to automatically harvest all of your records should you find your defense lines compromised.

Read More: What Is API Privacy and How to Protect Your Sensitive Data

4. Ensure Critical Data Is Secured

APIs and web applications often leak credentials and sensitive data without an organization ever knowing it happened.

By following these best practices, you  help to ensure that your API is secure:

• Identity extraction: Examine the parameters that control user profiles and make it impossible for the attacker to reverse engineer or guess tokens to harvest user data.
• Getting entire database objects: Ensure that the server returns only the values requested by the user, not entire database objects. Never leave data filtering to the client.
• Unauthorized file URL access: Dissect the mechanisms that generate temporary links to restricted files to ensure they can’t be reverse-engineered or hijacked with a custom API call.

Read More: How Improper Assets Management Leaves Your APIs Vulnerable to Attacks

The Only Automated API Security Testing Tool that Detects Business Logic Flaws

Armed with this list, you will drastically reduce the likelihood and severity of data breaches caused by this vulnerability cluster.

APIsec is the only fully automated API security testing solution that identifies business logic vulnerabilities at scale. By automating the process of identifying these flaws, APIsec helps organizations protect their applications and data from being compromised.

If you want to learn more about how APIsec can help you identify and fix business logic flaws, contact us for a free demo.