AWS Security: AppSec and Incident Response

When acquiring a company with AWS workloads, application security and incident response capabilities represent the final defensive layer that determines whether you’re inheriting a resilient, secure operation or a liability that could expose your organization to devastating attacks. While Parts 1 and 2 of this series covered foundational account controls and infrastructure protection, application security reveals whether the target company has embedded security throughout their software development lifecycle and can effectively respond to sophisticated threats.

Poor application security creates direct pathways for attackers to compromise business logic, access sensitive data, and maintain persistent access through custom code vulnerabilities. During M&A cybersecurity due diligence, these application-layer risks often remain hidden until integration efforts expose insecure coding practices, missing security testing, or inadequate incident response procedures that require extensive remediation before systems can be safely integrated.

In my experience conducting AWS security assessments for enterprise acquisitions, application security and incident response gaps are among the most complex to remediate post-acquisition. Unlike infrastructure issues that can be addressed through configuration changes, application vulnerabilities often require comprehensive code reviews, security testing implementations, and incident response capability development that can delay integration by 6-12 months and cost millions in remediation efforts.

Note: This is part 3 of a three-part series covering AWS security due diligence for M&A:

• Part 1 - AWS Security Due Diligence for Acquisitions (M&A): Account and Identity
• Part 2 - AWS Security Due Diligence for M&A: Infrastructure and Data Protection
• Part 3 - AWS Security Due Diligence for M&A: AppSec and Incident Response

In this post, I will cover the critical application security controls and incident response capabilities that M&A teams must evaluate before closing acquisitions that involve company workloads running on AWS, including secure development practices, automated testing, and response preparedness. I will also provide specific red flags, assessment questions, and remediation cost estimates to help acquirers identify application vulnerabilities that could impact deal value or create post-acquisition integration challenges.

Incident Response Capabilities Assessment

During M&A security due diligence, incident response capabilities reveal whether you’re acquiring a company that can quickly detect, contain, and recover from security threats or one that operates without proper preparation for inevitable security incidents. Poor incident response creates hidden liabilities that can surface as costly breaches and regulatory violations post-acquisition.

Incident Response Preparation and Planning

When a comprehensive incident response plan is maintained, it allows for rapid threat detection and coordinated responses across AWS environments. During an AWS security assessment, you should ensure the following capabilities are implemented:

Essential preparation components to verify:

• Documented incident response plans with clear roles and responsibilities
• Identified key personnel and external resources for incident response
• Pre-provisioned access control to AWS accounts for incident responders
• Pre-deployed forensic tools in isolated AWS security accounts
• Regular incident response simulations and testing
• Detailed response playbooks for common attack scenarios

Deal-impacting red flags:

• No formal incident response plan or outdated documentation
• Key personnel contact information missing or incorrect
• Incident responders lack appropriate AWS access permissions
• No forensic capabilities or investigation tools deployed to dedicated security account
• Incident Response procedures never tested or simulated

If an organization does not have a proper incident response plan they may be unable to effectively contain breaches, leading to extended incident duration, increased damage, and regulatory compliance violations that you’ll inherit.

Assessment questions for incident response preparation:

• Can you provide your current incident response plan and recent updates?
• Who are the key incident response team members and their contact information?
• What forensic tools and capabilities do you have deployed in an isolated AWS security account?
• When did you last test your incident response procedures?
• Do responders have pre-provisioned access to critical resources?

Post-Incident Learning and Improvement

Effective incident response requires continuous improvement based on lessons learned from actual incidents and simulations. This capability indicates organizational maturity and commitment to security improvement.

Critical learning capabilities to assess:

• Formal lessons learned process after each security incident
• Root cause analysis procedures that focus on process improvement
• Documentation of improvements implemented from past security incidents
• Regular review and updates to incident response procedures
• Integration of lessons learned into training and simulations

Red flags indicating poor learning culture:

• No formal post-incident review process
• Blame-focused culture rather than improvement-focused
• Same types of incidents recurring without process changes
• Incident response procedures never updated based on experience
• No tracking of response time improvements or capability enhancements

Financial impact considerations:

• Organizations without learning frameworks repeat costly mistakes
• Average cost of repeat incidents: 35% higher than initial incidents
• Integration delays when acquiring organizations with poor incident response maturity
• Regulatory penalties for failing to demonstrate security improvement efforts

Application Security Program Assessment

Application security controls protect against attacks targeting custom code, development processes, and software deployment pipelines. During M&A security due diligence, these controls reveal whether a company has embedded security throughout their development lifecycle or operates with vulnerable applications that create direct attack vectors.

Industry and Company Size Considerations:

Application security maturity varies significantly based on industry requirements and organizational size.

Financial services companies typically maintain more rigorous security testing and code review processes due to regulatory requirements, while early-stage startups may focus on speed-to-market over comprehensive security testing. Healthcare organizations often have strong data protection controls but may lack modern application security practices due to resistance to change.

Understanding these industry baselines helps set appropriate expectations during assessment.

• Enterprise organizations typically have formal security programs, dedicated security teams, and established development processes
• Mid-market companies often have security tools deployed, but may lack consistent processes or dedicated security personnel
• Startups frequently prioritize rapid development over comprehensive security testing, creating both risks and opportunities for security improvement

Secure Development and Training Programs

Companies should implement comprehensive security training and development practices that embed security throughout their software development lifecycle. Ensuring security is part of the entire technology team’s culture, rather than just the security team’s responsibility, helps all members understand the importance of maintaining secure practices during application development.

Essential development security practices:

• Security training programs for development teams
• Threat modeling integrated into application design
• Secure coding standards and guidelines
• Regular security awareness updates for developers
• Code review processes that include security analysis
• Using Infrastructure as Code (IaC) such as AWS CloudFormation or Terraform to repeat deployment processes

Deal-breaking warning signs:

• Developers receive no application security training
• No threat modeling or security design reviews
• Applications developed without security coding standards
• Code reviews focus only on functionality, not security
• Security considered only after development completion

Automated Security Testing and Code Reviews

Automated testing and systematic code reviews catch vulnerabilities early in the development process, reducing remediation costs and preventing security issues from reaching production.

Critical testing capabilities to verify:

• Automated security testing integrated into development pipelines
• Static application security testing (SAST) for source code analysis
• Dynamic application security testing (DAST) for running applications
• Regular penetration testing by qualified professionals
• Systematic code reviews with security focus
• Dependency scanning for vulnerable third-party components

Assessment red flags:

• No automated security testing in development pipelines
• Security testing performed only before major releases
• Code reviews conducted by same person who wrote the code
• No penetration testing or outdated testing results
• Vulnerable dependencies not tracked or managed
• Security testing tools deployed but never configured

M&A risk assessment:

Organizations without automated testing may have applications with undetected vulnerabilities that become attack vectors post-acquisition. Manual security testing doesn’t scale and creates gaps in coverage that sophisticated attackers will exploit.

Validation during due diligence:

• Request security testing reports from the past 12 months
• Review code review processes and security focus areas
• Assess penetration testing scope and remediation tracking
• Verify automated testing tool configuration and effectiveness

Software Deployment and Pipeline Security

Secure deployment processes and pipeline protection prevent attackers from compromising applications during the build and deployment process.

Essential pipeline security controls:

• Programmatic software deployment with security controls
• Centralized package and dependency management
• Regular security assessment of deployment pipelines
• Secure build environments with access controls
• Software integrity validation throughout deployment

Critical security gaps to identify:

• Manual deployment processes without security validation
• Uncontrolled access to build and deployment systems
• Third-party dependencies from untrusted sources
• No integrity checking of deployed software
• Pipeline security never assessed or updated

Financial impact considerations:

• Compromised pipelines can affect all applications, not just individual vulnerabilities
• Pipeline security remediation requires significant development process changes
• Integration delays when combining insecure deployment processes with secure systems

Cloud-native security controls for modern AWS architectures:

• Container image scanning and vulnerability management for ECS/EKS workloads using Amazon Inspector
• Serverless function security analysis for AWS Lambda applications
• Infrastructure-as-code security scanning for CloudFormation/Terraform
• API Gateway security configurations and rate limiting using services like API Gateway
• Event-driven architecture security for AWS EventBridge/SQS implementations

Cloud-native assessment considerations:

Organizations using containers, serverless functions, and microservices architectures require a different approach to security. Container images may contain vulnerable base layers, serverless functions often lack traditional security monitoring, and microservices create complex attack surfaces that conventional security tools struggle to protect. During due diligence, verify that cloud-native security practices match the architectural complexity of the organization’s environment.

While cloud-native architectures can improve security through better isolation and automated patching, they also introduce complexity that requires specialized security expertise to manage effectively during acquisition integration.

Development Culture and Security Ownership

Security Champion Programs and Ownership

Mature organizations embed security ownership throughout development teams rather than relying solely on centralized security teams.

Security ownership indicators to assess:

• Security champion or guardian programs within development teams
• Clear security responsibilities for development team members
• Regular collaboration between security and development teams
• Security metrics tracked and reported at team level
• Developer participation in security decision-making

Red flags indicating poor security culture:

• Security treated as someone else’s responsibility
• Development teams resistant to security requirements
• No security representatives embedded in development processes
• Security requirements imposed without developer input
• Adversarial relationship between security and development teams

Companies without embedded security ownership create cultural challenges that persist post-acquisition and require extensive organizational change management to remediate.

Assessment questions for security culture:

• How do development teams participate in security decisions?
• Who owns security requirements for each application?
• What security training do developers receive regularly?
• How do you measure security effectiveness at the team level?

From the Field

During my time at AWS conducting application security assessments for enterprise acquisitions, I’ve consistently found that organizations with strong infrastructure protection (covered in Part 2 AWS Security Due Diligence for Acquisitions (M&A): Infrastructure Protection Assessment Guide), but weak application security face the highest long-term risk exposure. Application vulnerabilities create direct paths to business-critical data that bypass network and infrastructure controls.

The most successful acquisitions I’ve observed implemented comprehensive application security assessments early in due diligence, allowing time to understand development practices, evaluate security testing maturity, and assess incident response capabilities. Organizations that discovered application security gaps after closing faced emergency remediation efforts that often required bringing in external security consultants and delaying integration by 6-12 months.

Organizations with mature application security programs demonstrate security ownership throughout development teams, automated testing integrated into deployment pipelines, and proven incident response capabilities. These companies integrate more smoothly and require minimal security remediation post-acquisition.

At Avinteli, we specialize in comprehensive AWS application security and incident response assessments for M&A due diligence, helping acquirers identify critical vulnerabilities in development practices and response capabilities before closing deals. Our experience evaluating complex enterprise environments ensures you get the detailed analysis needed to make informed acquisition decisions and plan successful integrations.

Other Blogs

• AWS Security Due Diligence for M&A: Accounts and Identity - Part 1
• AWS Security Due Diligence for M&A: Infrastructure and Data Protection - Part 2