Incorporating DevSecOps into Legacy Systems Playbook

December 16, 20234 min read

Playbook Objectives:

  • To simulate a realistic cyber-attack targeting legacy systems within a company that has recently adopted DevSecOps practices.
  • To understand the vulnerabilities unique to legacy systems within a modern DevSecOps pipeline.
  • To provide hands-on experience to the security team in identifying, responding to, and mitigating a cyber-attack on legacy applications and infrastructure.
  • To test the newly integrated security measures and incident response plan under a controlled, high-pressure environment.
  • To highlight the importance of cultural change towards security-focused development and operations.
  • To reinforce the urgency of incorporating security throughout the lifecycle of application development, particularly in outdated infrastructure.
  • To identify gaps in current security practices and amend the DevSecOps playbook accordingly for enhanced protection.

Difficulty level:



  • Company Name: FinCorp Solutions, a financial services company with a significant history, maintaining legacy systems dating back over 20 years.
  • Attack Scenario: A sophisticated APT (Advanced Persistent Threat) group targets FinCorp’s legacy account management system to siphon off sensitive financial data and access high-profile client accounts.
  • Characters: Alice, a DevSecOps engineer; Bob, the CISO (Chief Information Security Officer); Charlie, a legacy system administrator; Dave, a network engineer; Eve, a security analyst.
  • Network/System Description: FinCorp’s network includes a segmented legacy environment running outdated versions of finance management software that interface with modern DevSecOps-supported applications. The legacy infrastructure resides in a siloed network zone, connected to a modern cloud environment via secure APIs.


Legacy System Security in the Context of DevSecOps

Exercise Attack Steps:

  1. Reconnaissance: The APT group gathers intelligence on FinCorp’s systems, focusing on identifying externally facing endpoints of the legacy system.
  2. Initial Compromise: Utilizing a known but unpatched vulnerability within the outdated finance management software, attackers gain a foothold in the legacy network.
  3. Lateral Movement: Once inside the legacy system, attackers exploit weak internal security controls to move towards the secure DevSecOps application environment.
  4. Privilege Escalation: Through phishing emails impersonating IT staff, attackers trick high-level employees, gaining higher privileges that allow unrestricted access to sensitive data and systems.
  5. Data Exfiltration: Sensitive financial data is compromised, packaged, and exfiltrated to an external server controlled by the APT group.
  6. Persistence: Attackers install backdoors to ensure continued access, even after the initial security flaws are patched.
  7. Incident Response: Security alerts are triggered by abnormal data patterns, and the FinCorp Solutions incident response team led by Alice and Eve swings into action, initiating predefined protocols for containment, eradication, and recovery.
  8. Analysis and Reporting: Bob, the CISO, oversees a detailed analysis of the attack vectors, compromised systems, and data affected, leading to a formal report on the security posture’s weaknesses and strengths.
  9. Improvement and Retrospective: Charlie and Dave work alongside the security team to reinforce legacy systems’ defenses, refactoring code where possible, and integrating real-time security monitoring tools. The entire team participates in a retrospective to update the DevSecOps playbook incorporating lessons learned.
The exercise aims to underline the critical need to patch and update legacy systems, promote a shift in culture towards early detection and prevention, and reveal how DevSecOps can be a significant driver in improving legacy system security. FinCorp Solutions hopes to emerge more robust and resilience-ready to address both current and future cyber security challenges.