Why 2025’s Cybersecurity Landscape Demands a Complete Overhaul of Your IT Infrastructure

Summary

Today, organizations face an increasingly sophisticated array of cybersecurity threats. Among these, zero-day exploits have emerged as one of the most pressing concerns for businesses across all sectors. In fact, there has been a notable shift in the ratio of zero-day to n-day exploits. Where the ratio was once 62:38 (zero-day to n-day) we’re now seeing 70:30.
 
Zero-day exploits represent a particularly insidious threat because they target previously unknown vulnerabilities, giving security teams zero days to prepare before attacks begin. In contrast, n-day vulnerabilities are known vulnerability targets with one or more days between the disclosure and patch of the vulnerability.
 
Major technology providers like Microsoft are often targeted—case in point, the tech giant’s recent January 2025 Security Updates patch identified 159 vulnerabilities, including eight zero-days (three of these are under active exploitation). Recent high-profile incidents targeting Apple and Ivanti have similarly highlighted the devastating potential of these attacks, particularly when they target even slightly outdated systems and infrastructure.
 
The convergence of sophisticated attack methods with aging IT infrastructure has created a perfect storm for cybercriminals. As we move deeper into 2025, organizations must confront an uncomfortable truth: their legacy systems may be their greatest vulnerability. With cyber threats evolving at an unprecedented pace, the gap between modern security requirements and outdated infrastructure continues to widen, leaving many businesses exposed to potentially catastrophic breaches.

Understanding the zero-day threat

Zero-day vulnerabilities often exist in software or systems for months before discovery, providing ample opportunity for malicious actors to exploit them. While exceptions exist, the average time to patch a vulnerability is between two to five months, which offers cybercriminals an ample exploitation window. And this open window can grow exponentially larger when dealing with legacy systems, where patches may be delayed, incompatible, or simply unavailable.
 
The impact of these exploits extends beyond immediate technical concerns. When successful, zero-day attacks can lead to devastating consequences for organizations, including data breaches, financial losses and severe reputational damage. Organizations that experienced a data breach last year faced staggering costs, with the global average reaching $4.88 million per incident—up 10% from the previous year. The healthcare sector alone has seen a dramatic increase in such attacks and remains the most costly industry for breaches (an unfortunate designation it has held since 2011), with critical patient data and systems being compromised through outdated infrastructure vulnerabilities.
 
For many organizations, the challenge lies not just in detecting these threats but in maintaining the agility to respond effectively. Legacy systems, like those often used in healthcare, frequently lack the flexibility and compatibility required for modern security tools, creating blind spots in threat detection and response capabilities. This technological debt has become a critical liability in an era where rapid response can mean the difference between a prevented breach and a catastrophic incident.

The legacy system crisis

The persistence of legacy systems in modern IT environments represents a significant challenge for cybersecurity professionals. Many organizations continue to rely on outdated hardware and software, often due to budget constraints, operational dependencies, or the perceived complexity of upgrades. For example, despite advancements in cloud infrastructure and adoption, mainframe systems—considered a subset of legacy infrastructure—continue to play a vital role in company operations across sectors. To be clear, around 70% of Fortune 500 companies still use mainframe systems. Additionally, 43 of the world’s top 50 banks and eight of the top 10 payment companies rely on mainframes as their core computing platform.
 
This frequently results in a “patch gap,” or the time between when vulnerabilities are discovered and when they're effectively addressed. And patch gaps become particularly problematic with legacy systems. Organizations often find themselves unable to apply critical security updates due to compatibility issues or concerns about disrupting business operations. The result is an expanding attack surface that cybercriminals are increasingly adept at exploiting. In many cases, these vulnerabilities remain exposed for months or even years, creating persistent organizational risks.
 
The integration of modern security tools with legacy infrastructure presents another significant challenge. While artificial intelligence and machine learning have revolutionized threat detection and response capabilities, many legacy systems lack the necessary interfaces or processing capabilities to support these advanced security measures. This technological mismatch leaves organizations struggling to implement modern security solutions effectively, even as threats become more sophisticated.

The path forward: Modernization and security integration

Organizations must strategically modernize their infrastructure in a way that prioritizes security while maintaining operational continuity. This involves a comprehensive evaluation of the entire IT environment and its security implications. Modern infrastructure solutions offer built-in security features and seamless integration with advanced threat detection and response tools, enabling organizations to maintain a robust security posture.
 
Network segmentation represents another critical strategy in mitigating the risks associated with legacy systems and zero-day vulnerabilities. By dividing networks into isolated segments with strict access controls between them, organizations can contain potential breaches and limit lateral movement by attackers. While network segmentation won't completely eliminate the threat of zero-day exploits on legacy systems, it can significantly reduce their potential impact. However, it's important to recognize that implementing effective segmentation requires time and expertise, especially for organizations without mature network architecture. This means that segmentation should be viewed as one component of a comprehensive security strategy rather than a standalone solution—complementing rather than replacing the infrastructure modernization efforts.
 
Artificial intelligence and automation play crucial roles as well. AI adoption in cybersecurity is growing, so it’s no surprise that the AI cybersecurity market is expected to reach $134 billion by 2030. AI-driven security tools can process vast amounts of data to identify potential threats before they materialize, while automation helps ensure consistent application of security policies and rapid response to incidents. And new security tools, like cloud-based AI security, can help security teams detect threats and potential attacks in less than 60 seconds. Of course, these capabilities are particularly valuable in identifying and mitigating zero-day exploits, where speed of response is critical.
 
Keep in mind that the same AI advancements cybersecurity professionals use to thwart cybercriminals are used by cybercriminals to execute attacks. In a recent study, ChatGPT-4 was capable of exploiting 87% of the vulnerabilities included in the study. That said, without related CVE codes, GPT-4’s success rate fell to only 7%. This serves as yet another important example of why it is so crucial that organizations prioritize both infrastructure modernization and AI-enabled security solutions to maintain parity with—or better yet, advantage over—the sophisticated tools being deployed by threat actors.

The cost of inaction: Why modernization can't wait

As we move through 2025 and look to 2026 and beyond, the message is clear: organizations cannot afford to ignore the security implications of their legacy infrastructure. The cost of inaction—measured in potential breaches, data loss and reputational damage—far outweighs the investment required for modernization. With the average cost of a data breach now approaching $9.48 million in the U.S. and nearly $5 million globally, the financial implications alone make a compelling case for immediate action.

The path forward requires a strategic, multi-faceted approach. Organizations must start by thoroughly assessing their current infrastructure, identifying critical vulnerabilities and developing comprehensive modernization strategies that prioritize security without disrupting essential operations. Success in this endeavor demands a careful balance between technological advancement and operational stability—a challenge that becomes more pressing with each passing day. By embracing modern infrastructure solutions and AI-enabled security measures now, organizations can build the resilience needed to face not only today's threats but tomorrow's evolving challenges.