You Can't Spell API Security Without Bot Defense

Key Concepts:

1. Introduction: The Importance of Bot Defense in API Security

Bot defense is presented as a crucial component of any API security strategy.
APIs are ubiquitous, powering modern apps, microservices, and providing access to legacy systems.
The increasing number of APIs expands the attack surface.
The OWASP API Security Project highlights the top 10 API security vulnerabilities, many of which are closely linked to bot activity.

2. OWASP API Security Top 10 and Bot Association

Broken Authentication:
- Ranked #1, often exploited via brute force attacks and credential stuffing.
- Brute force attacks involve automated attempts to guess usernames and passwords.
- Credential stuffing uses breached credentials from other sites to attempt logins.
- Both methods rely on automation, thus involving bots.
- Mitigation requires robust bot defense mechanisms.
Unrestricted Resource Consumption:
- Occurs when APIs lack controls on incoming requests, leading to excessive costs, slow performance, and unavailability.
- Bots exacerbate this issue by causing sudden, unpredictable spikes in API usage.
- APIs designed for human interaction are particularly vulnerable to bot-driven resource exhaustion.
Unrestricted Access to Sensitive Business Flows:
- Involves automated exploitation of business processes not intended for automation.
- Examples:
  - Unauthorized Reselling: Bots purchase high-demand items (e.g., concert tickets) in bulk for resale at inflated prices. The Taylor Swift "Eras" tour ticket sales are cited as an example.
  - Reservation Blocking: Bots reserve all available time slots (e.g., hotel rooms) to prevent legitimate users from accessing the system.

3. Other API Vulnerabilities and Automation

The remaining seven OWASP API vulnerabilities are primarily due to implementation or configuration errors.
Broken Object Level Authorization: Unauthorized access to objects (e.g., medical records).
Broken Object Property Level Authorization: Unauthorized access to object properties (e.g., credit card numbers).
Broken Function Level Authorization: Unauthorized execution of functions (e.g., withdrawing money from the wrong account).
Improper Inventory Management: Losing track of APIs and their access controls.
Security Misconfiguration: General configuration errors.
Unsafe Consumption of APIs: One API consuming malicious content from another.
Server-Side Request Forgery (SSRF): API consuming unsafe resources due to a request.
These vulnerabilities can be identified and exploited using automated tools.

4. Tools for API Penetration Testing

Various tools are available for penetration testers and attackers to automate the discovery of API vulnerabilities.
Examples include Kiterunner (logo unreadable in the transcript).
The book "Hacking APIs" by Corey Ball is recommended for learning how to use these tools.

5. Integrating Bot Threat Modeling into API Security

Continuous API Endpoint Discovery: Essential to identify all APIs that need protection. You can't protect what you don't know about.
Vulnerability Assessment: Determine which API endpoints are vulnerable to bot attacks.
Adequate Protection: Ensure that vulnerable endpoints are adequately protected against sophisticated bots. Traditional methods like CAPTCHA and IP denial are often insufficient.

6. API Endpoint Categories Vulnerable to Bots

Login APIs: Prime targets for credential stuffing and MFA bypass attacks.
Inventory and Pricing APIs: Vulnerable to scraping bots that extract competitive data and strain infrastructure.
Purchasing/Transaction APIs: Exploited by bots for unauthorized reselling.
Credit Card Verification APIs: Targeted for carding, leading to chargebacks and fines.

7. Conclusion

A thorough understanding of API vulnerabilities and bot attack vectors is crucial for effective API security.
Organizations must proactively identify, assess, and protect their APIs against bot-driven threats.
Consider the business purpose of each API to assess how it might be exploited by bots.