Is Your Legacy or Custom Software Putting Your Business at Risk?

October is Cyber Security Awareness Month, making it a good time for businesses to review more than passwords, phishing awareness and employee training.

It’s an excellent time to revisit your cybersecurity strategy and shine some light on the software your business depends on daily.

When was the last time your organization conducted a cybersecurity health check or security audit of its legacy software, custom applications and business-critical code?

If you don’t have a definitive answer, it may be time to look under the hood.

Your Software May Be Working, But It Is Secure?

Legacy software often gets a bad reputation, but the reality is, many older applications continue to run critical business operations reliably for years.

The problem is, left unchecked, that software can accumulate risk over time.

• Frameworks become outdated.
• Dependencies stop being supported.
• Developers move on.
• Documentation disappears.
• Integrations multiply.
• Authentication requirements change.
• Security vulnerabilities discovered in components that were once considered acceptable in the original version.

Custom software can face many of the same challenges.

Custom builds are designed specifically for your organization, and there may not be an off-the-shelf security assessment telling you where the vulnerabilities are. If the original development team is no longer available, understanding the application’s architecture and security controls can become even more difficult.

The software may still work but the looming question is whether you know what risks are hiding inside it.

Vulnerability Exploitation Is Now a Leading Way Attackers Get In

This is not theoretical.

Verizon’s 2026 Data Breach Investigations Report found that 31% of breaches began with exploitation of software vulnerabilities, making vulnerability exploitation the leading initial access vector in the report. Verizon analysed more than 31,000 security incidents and 22,000 confirmed breaches across 145 countries.

For organizations running legacy or custom applications, that statistic should prompt a straightforward question:

Do we know which vulnerabilities exist in the software we operate?

Not knowing is a business risk.

What Does a Cybersecurity Health Check Actually Look At?

A cybersecurity health check, software security audit or code audit can provide an independent assessment of how secure and maintainable an application really is.

Depending on the system, an assessment can examine:

• Source code and potential security vulnerabilities
• Outdated frameworks, libraries, and dependencies
• Authentication and authorization
• User privileges and access controls
• Encryption and sensitive-data handling
• APIs and external integrations
• Database security
• Application configuration
• Logging and monitoring
• Third-party and open-source components
• Known attack surfaces
• Documentation and knowledge gaps
• Development and deployment practices
• Opportunities for remediation or modernization

This aligns with guidance from the National Institute of Standards and Technology (NIST), which identifies maintaining inventories of software, services, and systems as a critical component of cybersecurity risk management. NIST specifically includes custom applications, open-source software, APIs, and cloud-based applications within the software inventory organizations should maintain.

In other words, cybersecurity starts with knowing what you have.

An Audit Should Lead to Decisions, Not Just a Scary Report

A useful cybersecurity health check should do more than produce an extensive list of vulnerabilities.

Business leaders need to know:

• What is dangerous vs. a warning?
• What needs to be fixed immediately?
• What can be addressed through normal maintenance?
• Which risks are architectural?
• Does the application need modernization, or does it simply need better security controls and maintenance?

The answers matter and will determine how quickly you need to act.

A business should not automatically replace a stable legacy application simply because it is old. Likewise, it should not continue operating critical custom software indefinitely without understanding its security exposure. A software security audit provides the information needed to make that decision.

STEP Software’s audit approach examines areas including security, vulnerabilities, outdated frameworks, dependencies, architecture, technical debt, performance, and maintainability, helping organizations create a clearer roadmap for remediation or modernization.

The Cost of Finding Out After a Breach Is Much Higher

Cybersecurity is often treated as an IT expense, but a breach very quickly turns it into a business expense.

IBM’s 2026 Cost of a Data Breach Report found that the average cost of a data breach in Canada reached $7.11 million, the highest level recorded in the Canadian study. The report also found that the average breach involved approximately 28,500 compromised records and took an average of 205 days to complete its lifecycle.

Those numbers do not mean every software vulnerability will result in a multimillion-dollar breach. They do, however, demonstrate why understanding and prioritizing cyber risk before an incident happens matters.

There is also a supply-chain consideration. IBM found that supply-chain compromise was Canada’s largest breach cost driver, adding approximately CA$368,000 to the average cost of a breach.

Your software ecosystem is rarely isolated, we touched on this last month on our blog Bill C-36: Is your Business Ready?

Consider how many connections to vendors, APIs, cloud platforms, databases, payment systems, customers, and other business partners your current software has.

Every connection deserves consideration.

Why an Independent Software Audit Can Help

Internal IT teams are often the people keeping the business running. They know the systems, the history, and the workarounds. They may also be too close to the environment to conduct a comprehensive independent assessment.

A third-party software security audit can provide another perspective.

STEP Software’s Advisory division provides security and quality audits, code reviews and software assessments, including audits focused on performance and security. STEP also works extensively with legacy environments and custom software.

STEP’s legacy software practice is specifically focused on stabilizing and modernizing older systems while minimizing unnecessary disruption.

This rare combination matters.

The objective is not simply to identify a vulnerability. It is to understand what the vulnerability means for the business and what should happen next.

Cyber Security Awareness Month Is a Good Reminder to Look Under the Hood

The Canadian Centre for Cyber Security recognizes Cyber Security Awareness Month every October, encouraging Canadians and organizations to understand cyber risks and take practical steps to improve their security.

This October, consider adding one more question to your cybersecurity checklist:

“When was the last time we had our critical software independently assessed for security risk?”

If the answer is years ago, or nobody knows, that does not necessarily mean you have a crisis. But it does mean you have an information gap and information gaps are exactly what a cybersecurity health check, software security audit or code audit can help close.

Start With What You Already Have

Your legacy software may not need to be replaced and your custom application may not need to be rewritten. But your business should understand the risks associated with both.

A cybersecurity health check can establish a baseline, identify vulnerabilities, uncover technical debt and help leadership prioritize the next steps.

At STEP Software, we help clients move from “We think the system is secure” to “We understand the risks, we know what needs to be fixed and we have a plan.”

This October don’t just ask whether your people are cyber-aware, ask whether your software is. And if you need help finding the answers, drop us a line, we’ve been helping companies stay one STEP ahead for over 20 years.