Stuck With Legacy Systems? Urgent Steps CUs Should Take to Protect Against Cyber Attacks

Legacy systems are technical debt – burdens that organizations like credit unions and other financial institutions carry as they grow, yet cannot upgrade because of their mission-critical nature.

These systems, often outdated and cumbersome, are usually deeply embedded in the fabric of an organization’s operations. Users and other applications are deeply dependent on them. This makes the idea of upgrading or migrating away from these unsupported systems to a new one seem overwhelming, if not impossible.

As a result, many organizations find themselves kicking the proverbial digital can down the road, hoping that their legacy systems will continue to function without causing significant disruptions.

However, in a time where cyber threats are evolving at an unprecedented pace and news of data breaches is quickly covered in major media outlets, avoiding touching a legacy system is a gamble that credit unions can no longer afford to take.

Here, we’ll explore the risks of keeping your “head in the sand” and outline three steps your team can take to build a secure bridge to a future modern solution.

The Problems Inherent in Legacy Systems

1. Increased Vulnerability to Cyberattacks

One of the biggest issues with legacy systems is their inherent vulnerability to cyberattacks. Legacy systems often live on well past the vendor’s end of support –assuming the vendor is still in business!

This vulnerability is particularly concerning for credit unions due to the sensitive nature of the data they handle. When systems lose technical support, they no longer receive security patches or updates from their developers. As new vulnerabilities are discovered, there is no way to fix these flaws, leaving the system open to exploitation. For example, many banks still rely on legacy systems written decades ago – such as those using the COBOL programming language, which dates back to 1959. Despite being over 65 years old, COBOL was still being used by over 40% of U.S. banks as recently as the 2020s, as reported by Reuters.

Because of their outdated operating systems or underlying architecture, these legacy systems often cannot install endpoint detection and response (EDR) tools, which are available to protect systems against real-time threats. As a result, legacy systems are tempting targets for attackers looking for footholds in a network or a place to collect sensitive data. Many legacy systems operate on outdated protocols that can be easily intercepted, manipulated or bypassed by hackers.

2. Traditional Security Controls Fail

Another challenge with legacy systems is that standard security controls often fail – or cannot be implemented at all – because they lack compatibility with modern security protocols and tools.

Many legacy systems were designed without built-in security features (such as native encryption, authentication mechanisms or the ability to be easily patched), making them vulnerable to common attack vectors.

Making matters worse, skilled professionals familiar with these outdated technologies are scarce. As a result, the complexity of integrating modern security solutions with legacy systems is often outweighed by fixes focused on just maintaining functionality over security enhancements. This limits the ability of custom integrations, bug fixes and other updates to be applied, further limiting the effectiveness of security tools.

3. Too Critical to Change

Let’s face it, nobody maintains decades-old software because they like doing it. The only reason legacy systems exist is because they have become too operationally critical and painful to change – any disruption to their functionality can have severe consequences.

This criticality makes credit unions reluctant to make changes to the systems, even when those changes are necessary to improve security. Consequently, this fear of causing a system failure or disrupting business operations can lead to a “hands-off” approach, where legacy systems are left untouched despite their vulnerabilities.

This creates a paradox where the system is too critical to replace but too risky to leave as is.

Overcoming the Challenges of Legacy Systems: Three Key Steps to Take

Given the reputational, operational and financial costs that come with successful cyberattacks, credit unions can no longer afford to overlook the challenges posed by their legacy systems.

While replacing or upgrading a legacy system may not be feasible, there are several strategies and compensating controls that organizations can implement to mitigate the risks they present.

1. Shrink the Attack Surface

One of the most effective ways to protect a legacy system is by shrinking its attack surface. This can be achieved through micro-segmentation, a network security technique that isolates different parts of the network to prevent lateral movement by attackers.

Micro-segmentation is particularly valuable for legacy systems because it can be implemented even on outdated operating systems like Windows XP and Windows Server 2003. By segmenting the network around the legacy system, companies can limit access to only those users and applications that absolutely need it.

Additionally, micro-segmentation provides visibility into the network activity around the legacy system, allowing IT teams to identify undocumented dependencies, monitor connectivity to the device and assess potential risks.

2. Implement Access Controls

Once micro-segmentation is in place, the next step is to implement granular access controls to ensure that only authorized users can access the legacy system. This step is crucial because even if a system is segmented, it can still be compromised if unauthorized users gain access.

To start, credit unions should aim to limit access to known, trusted software clients and users. This not only reduces the risk of exploitation but also ensures that the legacy system can continue to operate without being exposed to unnecessary threats.

This can be managed with an identity and access management solution that can handle both on-premises and remote users, ensuring that security remains consistent regardless of how employees connect to the system. This same solution can help security teams monitor and control access from a dashboard, simplifying management and oversight.

3. Adopt a Phased Protection Strategy

Finally, credit unions should adopt a phased approach to securing their legacy systems.

Instead of immediately locking down the system, which could cause disruptions, IT teams should first operate the system in a detection mode. In this mode, the system continues to function as normal, but with enhanced monitoring of the network traffic to and from that legacy system.

Operating in detection mode allows IT teams to validate that their segmentation and access policies are functioning as expected. Once confirmed, the system can be switched to protection mode, where security measures are fully enforced.

Benefits From Taking Action Now

Taking proactive steps to secure legacy systems offers several significant benefits:

• Reduced cyber risk: By implementing these strategies, credit unions can significantly reduce the risk of a cyberattack on their legacy systems. This helps to protect them from potential financial losses but also helps to preserve their reputation by avoiding data breaches and other security incidents.
• Improved operational resilience: Securing legacy systems in a non-disruptive way allows companies to continue their operations smoothly while reducing their threat landscape. This helps to ensure that legacy systems remain functional and accessible to authorized users, while also being protected from potential threats.
• Cost-effective security enhancements: While replacing or upgrading a legacy system may be the ideal solution, it is often not feasible due to cost and complexity. Implementing segmentation and access controls provides a cost-effective alternative that enhances security without the need for a full system overhaul.

Bringing It All Together

Legacy systems, despite their critical role in credit union operations, pose a significant security risk due to their outdated architecture, design and vulnerability to cyberattacks. While upgrading these systems may not always be possible, credit unions can still take key steps to protect them by shrinking their attack surface, implementing granular access controls and adopting a phased protection strategy.

By doing so, credit unions can reduce their cyber risk, improve their operational resilience and achieve real security enhancements, ensuring that their legacy systems remain a strength rather than a liability as their business evolves.

Dr. Jaushin Lee is the Founder and CEO of Zentera Systems, a Milpitas, Calif.-based cybersecurity solutions provider.