Another Data Breach, Another Wake-Up Call for Mainframe Security

A recent security breach is an unsettling reminder of how even the strongest internal systems can fall victim to vulnerabilities within interconnected ecosystems.

For businesses relying on mainframes for their operations, the message is clear: Mainframe security is no longer confined to the system itself. Instead, it requires a proactive, ecosystem-wide approach to mitigate threats from increasingly sophisticated attack vectors.

Below, we examine the lessons learned from this high-profile airline data breach and provide a practical roadmap to fortify your mainframe against today's security risks.

The Recent Data Breach: A Weakest Link Story

A significant breach at a major airline recently exposed sensitive data, including millions of customer records. While the targeted system was not a mainframe, the nature of the attack stresses a critical vulnerability in interconnected supply chains. The attack exploited social engineering tactics, such as "vishing" (voice phishing) and "MFA fatigue" (overloading users with multi-factor authentication prompts), to compromise data stored by a third-party offshore call center.

Although the breach didn't involve financial or login credentials, even seemingly innocuous data like meal preferences was exposed. Such information can help attackers create sophisticated phishing schemes, potentially granting access to primary systems like mainframes. For businesses, this serves as a sobering reminder that their defenses are only as strong as the weakest link in their network.

Why Mainframes Are Not Invincible

Mainframes have long been regarded as pillars of security and operational efficiency. Renowned for their heavy-duty architecture, their perceived invincibility often breeds complacency, leaving them exposed to modern-day risks.

Today’s mainframes are deeply integrated with cloud environments, external applications, and third-party tools. This connectivity enhances efficiency but also expands the attack surface, making mainframes more susceptible than traditional systems. Key vulnerabilities include:

1. Supply Chain Risks

Third-party software, open-source dependencies, and accidental exposure of developer credentials can all be exploited by attackers seeking entry into mainframe environments.

2. Human-Centric Attacks

Phishing, vishing, and other social engineering methods can compromise administrative credentials, bypassing even the strongest technical barriers.

3. Privileged Access Mismanagement

Unmonitored privileged accounts are still a blind spot in many organisations, enabling malicious insiders or hackers to operate undetected.

4. Network Segmentation Gaps

Poor segregation of IT environments allows attackers to pivot from less secure systems into high-value mainframes.

It’s these challenges that urge the necessity of viewing mainframe security as part of a broader enterprise defense strategy, rather than in isolation.

Building Resilient Mainframe Defenses

To address these vulnerabilities, your organisation must adopt a security framework that is both preventive and holistic. Below, we outline five core pillars required to strengthen mainframe defenses and ensure optimal protection.

1. Conduct Comprehensive Security Audits

Regular security assessments are essential for uncovering hidden weaknesses. A complete audit framework should include:

• Code Reviews to identify unpatched vulnerabilities.

• Access Management Assessments to enforce least-privilege principles and deactivate unused accounts.

• Configuration Optimisation to align system settings with industry best practices while monitoring privileged activities.

These reviews help establish a solid baseline for ongoing security enhancements.

2. Develop Strategic Incident Response Plans

With breaches becoming inevitable, the speed and effectiveness of your incident response play a decisive role in minimising damage. A mainframe-specific response strategy should focus on the following:

• Seamless SIEM Integration to enable real-time correlation of threats across enterprise systems.

• Defined Responsibilities for experts managing containment, recovery, and post-incident reviews.

• Frequent Simulations to ensure your team is well-prepared for real-world attack scenarios.

When all team members know their roles, your organisation can reduce downtime significantly during an attack.

3. Leverage Advanced Threat Detection

While traditional logs provide historical data, modern security requires real-time monitoring powered by AI and machine learning. Areas to prioritise include:

• Behavioral Anomaly Detection, which identifies suspicious user activity, such as login attempts from unusual locations.

• Privileged Access Alerts, highlighting unauthorised administrative actions.

• Automated Exfiltration Monitoring, alerting teams to potential data breaches before significant damage occurs.

Sophisticated monitoring systems provide a guardrail against emerging threats that evade traditional detection methods.

4. Empower Employees Through Training

Human error is the leading cause of breach incidents. Educating your workforce plays a very important role in reducing your security risks. Effective training programs focus on:

• Realistic phishing and social engineering simulations.

• Tailored content highlighting specific risks related to employees' roles.

• Encouraging an open culture of risk reporting, turning employees into active defenders instead of accidental enablers of threats.

When employees are properly trained, they form the first line of defense in your security strategy.

5. Prioritise Regulatory Compliance

As data regulations tighten, mainframes offer inherent advantages with built-in encryption and role-based access controls – if they’re set up and used correctly. However, staying compliant still requires:

• Regular data privacy audits spanning all systems.

• Integration of compliance into operational workflows to ensure consistency.

• Maintenance of comprehensive, retraceable audit trails to streamline inspections.

By prioritising compliance, your organisation not only avoids penalties but also builds trust with stakeholders and clients.

Taking Action

Mainframe security can’t rely on legacy approaches alone. It requires bold action and enterprise-wide collaboration. The recent breach at a major airline should serve as a wake-up call to reevaluate vulnerabilities in your broader ecosystem. Adopting these five pillars can help your business create a resilient, proactive framework that protects operations, sensitive data, and your company’s reputation.

To further secure your mainframe environment, consider partnering with experts who specialise in defense strategies. CPT Global offers tailored solutions to identify weaknesses, implement solutions, and ensure your systems comply with regulatory standards. Don’t wait until a catastrophic event forces change. As anyone in IT knows, acting now is always best.

Proactive planning and investment today mean fewer risks tomorrow. When you’re ready to talk security, get in touch with CPT Global. Our experts can help you start building stronger, smarter mainframe defenses today, empowering your business for tomorrow.