Understanding Security Debt in Software Development: Risks, Causes, and Solutions

Software security is more than a buzzword; it’s a cornerstone of an organization's resilience to cyber threats. However, many organizations delay patching vulnerabilities to prioritize faster product launches or to cut costs.

According to the State of Software Security 2024 Report, approximately 70% of organizations have accumulated security debt, with 45% of that debt tied to critical vulnerabilities. This issue affects organizations of all sizes and stems from internal code bugs and the use of third-party software.

How does security debt arise? Why does it pose a threat? And what steps can organizations take to identify and eliminate it? This article has all the answers.

What is Security Debt?

Security vulnerability debt, or simply security debt, refers to the accumulation of unresolved issues that grow into serious risks over time.

Outdated services, forgotten patches, configuration errors, and insecure code all "inflate" the security debt of a system or software. Over time, as these issues accumulate and the debt grows, the risk of attackers exploiting the system rises, making it an easy target.

Understanding Security Debt

Security debt can be seen as a deferred liability. Like financial debt, unresolved vulnerabilities create an obligation to remediate them later. Unfortunately, this often happens under stressful conditions, such as after a data breach or cyberattack. The longer vulnerabilities go unaddressed, the more difficult and expensive they become to fix, both in terms of resources and the organization’s reputation.

Comparison with Technical Debt

In development, "technical debt" refers to the compromises made for speed, such as writing low-quality code or building from "rubble" that makes it difficult to modify or extend the system later. Security debt is similar, but its focus is different: vulnerabilities within the security system.

Lack of experience, insufficient testing and documentation, delayed refactoring, incorrect or insufficiently flexible decomposition, and stakeholder pressure can all lead to technical debt. Continuous software development increases complexity and degrades structure if technical debt is not addressed.

Martin Fowler created his own classification of technical debt in 2009, showing how long this issue has been occurring.

The more complex the system becomes, the harder it is to "pay off" the debt later. Technical debt that is ignored will likely hinder future development. The same applies to lingering security vulnerabilities.

Both types of debt often accumulate unnoticed, but security debt is more dangerous. It threatens your reputation, finances, and entire business. If you ignore these issues with a mindset of "we'll do it next time," you’re setting a time bomb for yourself and your customers.

Common Causes of Security Debt

Security debt rarely appears on its own—there are always underlying circumstances. Why do companies fall into this trap? Here are some common reasons why security vulnerabilities in software occur and persist:

• Compressed development schedules. Tight deadlines prioritize releasing new features over addressing security, leading to accumulated debt.
• Limited resources. A lack of expertise or budget to address all issues in a timely manner can delay the resolution of vulnerabilities.
• Lack of awareness. Failure to identify vulnerabilities due to inadequate tools or processes can leave security vulnerabilities remaining in the software.
• Inadequate testing. Sometimes, an organization does not thoroughly test software from start to finish during the development lifecycle.
• False sense of security. If no issues are visible, an organization may mistakenly believe it is safe and neglect the timely updates and testing.

The reasons for accumulating security debt often go deeper than a simple lack of time. However, it is still not a good practice.

Addressing vulnerabilities later is better than never, but if "later" never comes, existing security debt only compounds further.

Risks Related to Security Debt

Sooner or later, security debt becomes a significant obstacle: risks increase, and development teams spend more and more time dealing with the consequences. Accumulated security debt is not just a technical problem—it’s a potential threat to the entire organization. Here are the key risks:

1. Threats from cyberattacks. The more unresolved vulnerabilities there are, the easier it becomes for attackers to find an entry point. This can lead to data leaks, system hacks, or complete shutdowns.
2. Financial loss. Cyber-attacks often result in direct financial losses, including fines for breaches, compensation for victims, and the cost of restoring infrastructure.
3. Loss of trust. When customer data falls into the hands of hackers, it severely damages a company's reputation. It can take years to rebuild trust.
4. Remediation costs. The longer problems remain unresolved, the more difficult and expensive they are to fix. Patches and updates can turn into large projects that require additional specialists.
5. Slow project development. Security debt limits the team's ability to move forward. Rather than progressing, the team must revisit and resolve old issues.

It won't surprise anyone to hear that security debt must be paid off immediately. The longer it accumulates, the more expensive the solution becomes—and the greater the risk that one of these issues will turn into a disaster.

How to Identify Security Vulnerability Debt

Practical vulnerability assessment requires the right technology and well-configured processes within an organization. Regular audits, employee training, and advanced tools help minimize risk and make your system more resilient to cyber threats.

Developers who address vulnerabilities promptly are four times less likely to encounter critical security flaws—so it’s crucial to act quickly!

While starting with "simple" steps is fine, it’s much more important to continuously work to improve your security system and address its vulnerabilities. It's best to implement specific services and assign specialists to tackle both technical and security debts.

Asset Data Collection and Security Vulnerability Identification

The best way to begin addressing security debt is to inventory all your software assets, whether proprietary, commercial, or open source. You should also create a software specification or list of components for each asset you support. Simply put, you can't protect what you don't know.

Not all software security vulnerabilities carry the same level of risk. The Common Vulnerabilities and Exposures (CVE) list provides descriptions of commonly known vulnerabilities, and some security vendors offer vulnerability disclosures with mitigation information. You can start by reviewing your vulnerabilities and comparing them to those in the CVE. Identifying the problem is the first step toward fixing it.

An audit like this will give you a "bird's eye view" and help determine where to start and what to prioritize.

Checking Dependency Chains

Modern applications are rarely built entirely from scratch; developers commonly use third-party libraries, frameworks, and packages to speed up development. However, any such dependency can become a weak link if not properly supported.

Why is this important?

• If a library or framework you’re using has a known but unpatched vulnerability, it will automatically propagate into your project.
• Older versions of libraries often no longer receive security patches.
• Your project may rely on libraries that, in turn, depend on other libraries containing vulnerabilities.

These are a few tools that can help with dependency analysis: Dependabot, OWASP Dependency-Check, and Snyk.

Conducting Penetration Tests

A penetration test (pentest) is a simulated hacker attack on your systems to identify software security vulnerabilities that attackers could exploit.

Pentesting helps you understand how systems behave under real-world attack scenarios and uncovers vulnerabilities that may not be visible in automated scans. It also gives insight into the potential consequences of a "successful attack."

We have previously covered how to perform a penetration test.

Assessing Safety Processes and Culture

People often represent the greatest risk factor in security, compounded by insufficient standards, poor documentation, or a lack of experience and time. Under these circumstances, phrases like "we'll do it next time," "it hasn't become a problem yet," or "there's no time to fix the vulnerability" tend to surface.

To mitigate these risks, ensure clear policies are established for software updates, access control, and incident response. These processes should be thoroughly documented and understood by all stakeholders. Implementing threat modeling practices can further help teams anticipate and effectively respond to attacks. Even if a vulnerability has not been identified yet (such as a zero-day vulnerability), these measures facilitate swift collaboration and resolution.

In general, improving communication between development and other teams is also crucial. It helps pinpoint which vulnerabilities have already been exploited and begin fixing them. Remember: the sooner vulnerabilities are addressed, the better.

Most importantly, you can automate security testing and debugging throughout every stage of CI/CD. To stay motivated, consider this: delaying action could mean spending 10 times as much tomorrow on remediation as you would spend today to release a timely patch or solution.

Solutions to Manage and Reduce Security Debt

No one wants their data falling into the hands of intruders. That's why proper security remediation isn't just about protecting your systems—it’s also about earning your customers’ trust. While fixing accumulated problems isn’t easy, failing to address them now or during the development process will result in a much higher price later.

According to the report mentioned earlier, only 35% of applications successfully manage the ongoing elimination of all critical security debts. This highlights how few teams work quickly enough to prevent security debt from growing. Strive to be one of that 35thoseere are some best practices to avoid accumulating security debt:

• Prioritize security in your development process from the start.
• Conduct regular security assessments, code analysis, and penetration testing to identify and address vulnerabilities early on.
• Continuous monitoring of systems and networks helps identify security issues as they arise so they can be addressed quickly. Automated tools can help track and manage security liabilities.
• Establish a regular patch management process to ensure all systems receive the latest security patches and updates. Prioritize critical vulnerabilities that pose the most significant risk.
• Modernize your IT infrastructure to reduce the risk associated with outdated technology.
• Develop a structured plan to address your security backlog by identifying the most critical issues first. This plan should include timelines, resource allocation, and clear remediation responsibilities.

Here is a little more about the tools you might need to deal with security vulnerabilities.

Security Vulnerability Tools

Effective security vulnerability management requires tools that help you find, prioritize, and remediate problems. We recommend reviewing these categories of tools and popular solutions:

• Vulnerability scanners: Nessus, Qualys, OpenVAS, Rapid7 Nexpose.
• SAST (static application security testing) tools: SonarQube, Checkmarx.
• DAST (dynamic application security testing) tools: OWASP ZAP, Burp Suite.
• Monitoring and response tools: Splunk, Datadog, ELK Stack, PagerDuty.
• Pentest platforms: Hack The Box, Cobalt, PentesterLab, Kali Linux.
• CI/CD integration tools: Snyk, GitLab Security, Trivy, Aqua Security.

Conclusion

Security debt threatens a business, slows development, and creates many obstacles. By adopting modern approaches, following best practices, and using automation tools, you can avoid problems and turn security into a competitive advantage.

Remember: timely prevention is always cheaper and more effective than dealing with the consequences!