Automated application security testing is a critical component of a robust security strategy. By implementing a comprehensive testing approach that leverages automation, organizations can improve their security posture, maintain compliance, and enable faster delivery of secure applications. This article explores the key considerations, strategies, and best practices for implementing automated application security testing based on the guidance provided in the Cloud Security Alliance (CSA) Cloud Controls Matrix (CCM).

Where did this come from?

This article is based on the AIS-05 control from the CSA Cloud Controls Matrix v4.0.10 - 2023-09-26. The CCM is a cybersecurity control framework for cloud computing that provides a detailed understanding of security concepts and principles. It can be downloaded from the CSA website. For more information on application security testing, refer to the OWASP Testing Guide and the AWS Web Application Firewall Developer Guide.

Who should care?

• Software developers responsible for building secure applications
• DevOps engineers tasked with integrating security testing into CI/CD pipelines
• Security architects designing application security strategies
• Compliance officers ensuring adherence to regulatory requirements
• Product owners balancing speed of delivery with security and compliance needs

What is the risk?

Inadequate or absent application security testing can lead to:

• Exploitation of vulnerabilities by attackers, resulting in data breaches, system compromises, and reputational damage
• Non-compliance with industry regulations and standards, potentially incurring fines and legal consequences
• Increased remediation costs and delays in application delivery due to late discovery of security issues

Automated testing helps mitigate these risks by enabling consistent, scalable, and efficient detection of security weaknesses throughout the software development lifecycle (SDLC). However, automation alone is not a silver bullet and should be combined with manual testing and expert analysis for optimal risk reduction.

What's the care factor?

Application security should be a top priority for any organization developing or deploying software. The potential impact of a security breach can be severe, ranging from financial losses to irreparable damage to customer trust and brand reputation. Investing in automated security testing is a proactive measure that demonstrates a commitment to protecting sensitive data and maintaining a strong security posture.

The level of priority given to automated testing should be proportional to the criticality and sensitivity of the applications being developed. High-risk applications, such as those processing financial transactions or personal data, warrant the highest level of testing rigor. However, even lower-risk applications can benefit from a baseline level of automated testing to catch common vulnerabilities and coding errors.

When is it relevant?

Automated application security testing is relevant in situations where:

• Applications are being developed or updated frequently
• The application portfolio is large and diverse, making manual testing impractical
• Compliance with security standards and regulations is required
• DevOps practices like continuous integration/continuous deployment (CI/CD) are being adopted

It may be less relevant for:

• Very small or simple applications with limited attack surface
• Legacy applications that are stable and rarely updated
• Applications with extremely high security requirements that demand extensive manual testing and code review

What are the trade-offs?

Implementing automated application security testing comes with some costs and considerations:

• Tools and infrastructure: Automated testing tools can be expensive, and may require dedicated hardware or cloud resources to run efficiently.
• False positives: Automated tools can generate noise in the form of false positive results that require manual triage, potentially consuming valuable developer time.
• Integration effort: Incorporating automated testing into the SDLC and CI/CD pipelines requires upfront planning and ongoing maintenance.
• Training and expertise: Effective use of automated testing tools often requires specialized knowledge and skills that may necessitate additional training for development and security teams.

How to make it happen?

1. Define testing goals and requirements
   • Identify the types of security weaknesses to be detected
   • Determine the required programming language and platform support
   • Establish metrics for tracking the effectiveness of the testing program
2. Evaluate and select automation tools
   • Consider factors such as ease of use, integration capabilities, and false positive rates
   • Look for tools that offer API access for integration with CI/CD pipelines
   • Examples include static application security testing (SAST) tools like SonarQube and dynamic application security testing (DAST) tools like OWASP ZAP
3. Integrate testing into the SDLC
   • Implement testing at multiple points, such as in developers' IDEs, during build processes, and as part of deployment workflows
   • Ensure that testing failures break the build and prevent deployment to production
   • Automate the creation of tickets for tracking and remediation of discovered issues
4. Establish feedback loops
   • Monitor metrics like vulnerability counts and developer response times
   • Tune testing tools to minimize false positives
   • Foster a culture of collaboration between development and security teams
5. Combine with manual testing
   • Perform manual code reviews and penetration testing to cover scenarios not easily tested through automation
   • Engage third-party security experts to provide independent validation and uncover gaps in automated test coverage

What are some gotchas?

• Inadequate coverage: Automated tools may not be able to test all application components or security scenarios, leading to gaps in coverage. Combine with manual testing.
• Performance impact: Some testing tools can significantly slow down build and deployment processes if not configured properly. Optimize tool settings and consider distributing testing across multiple agents.
• Permissions and access: Automated testing may require special permissions, such as the ability to create and destroy cloud resources. Ensure that the necessary IAM permissions (e.g. ec2:StartInstances, ec2:TerminateInstances for testing in AWS) are granted to the testing tools and processes. See the AWS IAM documentation for details on configuring permissions.
• Legacy code: Automated tools may have difficulty analyzing legacy codebases that use outdated frameworks or patterns. Consider incremental modernization and refactoring efforts in parallel with testing improvements.

What are the alternatives?

While automated testing is highly recommended, there are other approaches that can supplement or substitute for it in certain situations:

• Manual code review: Having experienced developers manually review code for security issues can be effective, but doesn't scale well.
• Penetration testing: Engaging external security experts to simulate attacks and attempt to breach the application can uncover gaps missed by automated tools.
• Bug bounties: Offering rewards to external researchers who responsibly disclose vulnerabilities can be a cost-effective way to crowdsource security testing.
• Secure coding practices: Training developers to write secure code from the start can reduce the need for extensive testing later in the SDLC.

Explore further

• OWASP Top 10: A standard awareness document for developers and web application security, representing a broad consensus about the most critical security risks to web applications.
• SANS Institute - Continuous Security Testing: A white paper exploring the role of continuous testing in a DevSecOps environment.
• CIS Control 16: Application Software Security: Detailed guidance on managing the security lifecycle of application software.

Conclusion

Automated application security testing is a crucial practice for any organization serious about building and maintaining secure software. By implementing testing throughout the SDLC, leveraging a combination of automated tools and manual techniques, and continuously monitoring and improving the testing process, organizations can reap the benefits of increased security, compliance, and development velocity. The guidance provided in the CSA CCM offers a solid foundation for getting started with automating application security testing.

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