Legacy Systems – The Hidden Threat in Your Company. Why Modernization Can’t Wait.

Is your company still relying on solutions implemented more than a decade ago?

If so, you are not alone. Statistics show that legacy systems are still present in over 60% of organizations worldwide. For many companies, they are the very “heart” of operations – ERP systems, CRM systems, CAD systems, or financial applications written years ago. However, maintaining legacy systems instead of modernizing them leads to ever-increasing costs and growing exposure to risks.

At first glance, they may seem to work fine. But in practice, keeping legacy systems is like a ticking time bomb – it restricts growth, blocks innovation, and exposes you to cyberattacks.

What are legacy systems and why are they a problem?

The term legacy system refers to technologies that, for various reasons, are still functioning within organizations, even though they no longer meet current market requirements. These may include:

• legacy software without updates or patches,

• systems with legacy code – expanded over years, difficult to maintain and modify,

• systems running legacy software that require costly support from external consultants,

• legacy hardware – servers, devices, and infrastructure incompatible with new architectures,

• ERP and CRM systems built in pre-cloud technologies.

Some of them operate in so-called legacy mode – a compatibility mode that allows old applications to run in new environments. But this is only a temporary fix – it limits efficiency and creates new error risks.

What are the risks of maintaining legacy systems?

1. Cyber threats and vulnerabilities
Without updates, legacy software is an easy target for cybercriminals. Attacks often exploit systems with legacy files where data does not meet modern encryption standards.

2. High costs and limited access to specialists
Legacy support is becoming increasingly expensive. Technologies such as COBOL or older ERP versions require unique skills, and the number of experts is shrinking. Repair costs rise, and response times get longer.

3. Roadblock to digital transformation
Modern initiatives – cloud, AI, automation – require integration with systems that comply with new security standards, flexibility, and interoperability. Unfortunately, legacy software often cannot meet these demands.

4. Software rot and entropy
Over time, legacy code suffers from software brittleness – it becomes fragile, hard to develop, and every change can trigger a cascade of errors. Documentation disappears, team knowledge disperses, and the risk of paralysis grows.

5. Risk of failures and data loss
The absence of proper data migration procedures means that a failure of legacy hardware or ERP systems based on old databases can halt the entire company. Backup and business continuity in such a scenario are merely an illusion.

Industry insights – eye-opening facts

The MOVEit platform attack in 2023 exposed the data of over 93 million people – the cause was a vulnerability in an outdated component. A prime example of how legacy software becomes an entry point for cybercriminals.

In the UK, the Legal Aid system, built on legacy hardware and lacking support, was attacked in 2024. Data of 2.1 million people was leaked.

Barclays Bank reported over 30 major outages within two years – caused by ERP and CRM systems built on legacy code. Losses were counted in millions of pounds.

IBM X-Force Report 2025 showed that the manufacturing sector has been the top target for cyberattacks for four years in a row. One reason is legacy software that does not comply with modern security and automation standards.

Legacy system modernization – how to approach the challenge?

1. Audit and risk analysis
Start by identifying systems. Check which applications run on legacy hardware, which require legacy support, and which are business-critical.

2. Step-by-step strategy (legacy modernization)
Not everything needs replacing at once. A popular approach is brownfield architecture – gradually replacing components and integrating with systems built on new integration and virtualization standards.

3. Data migration
Securely transferring data from legacy applications and databases based on outdated formats is key. Modern systems with updated interfaces and algorithms provide better information management.

4. New standards and features
Modern systems must support automation, monitoring, cloud, and reporting standards. This ensures compliance and prepares the organization for growth.

5. Legacy transformation – a step into the future
Full transformation means moving from legacy systems to modern platforms. It’s not just about replacing “old with new” – it’s about implementing systems with new solutions, data, and technologies that scale business and prepare it for years to come.

Summary

Legacy systems are one of the biggest challenges modern companies face. They may still work, but maintaining them comes with high costs, cyberattack risks, and blocked innovation.

The solutions include:

• audit and prioritization,

• step-by-step modernization,

• data migration and integration with new standards,

• moving toward full legacy transformation for security and flexibility,

• implementing modern ERP, CRM, and CAD systems aligned with today’s business requirements.

Every year of maintaining legacy systems increases the risk. Modernization is not a cost – it is an investment in the future, security, and growth.