For decades, IBM’s AS400 (now IBM i) has been the backbone of mission-critical operations in banking, manufacturing, logistics, and healthcare. Renowned for its stability, integrity, and processing power, it’s a platform trusted by global enterprises to manage vast amounts of sensitive data. But even the strongest legacy systems face modern challenges. Connectivity, cloud integration, and third-party access have expanded attack surfaces — and that’s where AS400 penetration testing becomes indispensable.
Why legacy systems need modern security
The AS400 was built for reliability, not today’s hyperconnected world. Originally designed for closed networks and controlled access, it now interacts with cloud APIs, web frontends, and remote administration tools. This evolution introduces exposure that its original security model never anticipated.
Cybercriminals don’t discriminate based on technology age. They target what’s accessible, valuable, and overlooked — and legacy systems often fit all three categories. AS400 environments are especially attractive because they store critical business logic, payment data, and customer records that newer systems depend on.
Common vulnerabilities uncovered through AS400 penetration testing
Even well-maintained IBM i environments can contain misconfigurations or outdated controls that leave them vulnerable to attack. Common findings include:
-
Default or weak credentials: administrative accounts (e.g., QSECOFR) with unchanged passwords.
-
Excessive authorities: users granted ALLOBJ or SECADM without necessity.
-
Unencrypted communications: FTP and Telnet still enabled, exposing credentials in cleartext.
-
Unpatched components: outdated versions of IBM Navigator for i or other management tools.
-
Insecure integrations: middleware or third-party applications that bypass native security.
-
Lack of monitoring: insufficient auditing in QAUDJRN, making intrusion detection difficult.
These issues often go unnoticed because standard vulnerability scanners have limited visibility into AS400-specific configurations. Manual, expert-led testing is essential to uncover deeper flaws.
What AS400 penetration testing involves
A proper AS400 penetration test doesn’t just look for known bugs — it simulates realistic attack paths specific to the IBM i ecosystem. A typical engagement includes:
-
Reconnaissance and enumeration: identifying system values, active services (e.g., 5250, ODBC, DRDA), and user profiles.
-
Access testing: evaluating password policies, brute-force resistance, and remote access security.
-
Privilege escalation: assessing whether limited accounts can gain special authorities.
-
Lateral movement: testing how compromise in one environment could affect others (e.g., ERP or finance systems).
-
Data exfiltration scenarios: safely simulating how an attacker might extract sensitive files or records.
-
Audit and log validation: ensuring system logs (QAUDJRN) capture relevant activity for incident response.
The objective is to demonstrate real-world exploitability — not to disrupt operations, but to measure resilience under realistic conditions.
Business benefits of AS400 penetration testing
Beyond the technical value, testing legacy environments provides strategic benefits:
-
Operational assurance: validates that modernization efforts haven’t introduced new risks.
-
Regulatory compliance: supports PCI DSS, SOX, GDPR, and other frameworks requiring periodic testing.
-
Cost prevention: fixes found during testing are far cheaper than breach recovery.
-
Audit readiness: produces documented evidence of proactive security practices.
-
Confidence for modernization: ensures that migrating workloads or connecting to new systems doesn’t compromise core stability.
Executives gain clarity, security teams gain actionable insight, and the organization gains measurable resilience.
Why expertise matters
Testing AS400 systems requires specialized skills and deep platform knowledge. Generic penetration testers may lack the experience to navigate IBM i’s unique architecture, authority structures, and CL commands. Partnering with experts who understand both the technical and business layers of AS400 is crucial for accurate, safe, and valuable results.
www.superiorpentest.com provides dedicated services for legacy environments, helping enterprises modernize security without risking uptime. Their team performs thorough, standards-based AS400 penetration testing, combining IBM i expertise with advanced ethical hacking techniques to deliver precise, actionable findings.
By understanding where vulnerabilities truly lie, organizations can secure their most reliable systems for the future — ensuring that legacy strength becomes part of modern resilience, not a hidden liability.