Why outdated systems pose the biggest threat to your digital future and what insurers must do to secure them
As P&C insurers accelerate digital transformation, one of the most complex and high-stakes challenges security leaders face is securing the modernization of core systems. These legacy platforms, often decades old, are deeply embedded in underwriting, claims, billing, and policy administration. They’re also increasingly difficult to protect, maintain, and integrate with today’s cloud-native ecosystems.
For executive leaders tasked with updating their core systems, this presents a dilemma: modernize too aggressively, and you risk destabilizing business-critical operations; move too slowly, and you leave known vulnerabilities exposed.
This is the legacy core trap, and navigating it requires a delicate balance between modernization and cyber hardening.
Legacy Systems: The Double-Edged Sword
Legacy systems are often the backbone of a carrier’s daily operations. Many were custom-built, heavily customized, or acquired through mergers, making them difficult to upgrade or replace. Their core codebases may be written in outdated languages, run on unsupported operating systems, or have limited compatibility with modern security tools.
While these platforms continue to perform essential business functions, they also represent some of the highest-value attack surfaces in an insurer’s digital environment.
The challenge is that legacy systems were not built with modern cybersecurity threats in mind and often lack basic controls such as multi-factor authentication (MFA), encryption at rest, or robust access logging. Legacy systems also cannot always support agent-based endpoint detection or API security layers
As insurers move to more agile, cloud-native architectures, legacy systems can become invisible weak points, staying unmonitored, unpatched, and highly exposed.
The Security Risks During Modernization
Cloud migration and modernization projects are essential for scalability, speed to market, and customer experience. But the transitional phase, from legacy infrastructure to modern platforms, is when insurers are most vulnerable.
Some key risks during modernization include:
- Data Exposure During Migration: Sensitive data moving between environments, like cloud storage, data lakes, or core platforms, may be insufficiently protected without proper encryption, key management, and transfer validation.
- API Vulnerabilities: Exposing legacy systems through new APIs can inadvertently open backdoors, especially if proper access controls and input validation are not enforced.
- Hybrid Infrastructure Complexity: Running in a hybrid state, where cloud platforms and legacy systems coexist, can lead to blind spots in visibility, inconsistent security controls, and unclear ownership of risk.
- Insecure Decommissioning: Old systems, test environments, or temporary interfaces that are improperly decommissioned can leave residual risk long after a migration is complete.
Modernization is a technical challenge, but more so, it’s an operational risk event that requires strong governance, careful planning, and continuous oversight from security and IT leadership.
Why “Rip and Replace” Isn’t Always the Answer
While the instinct may be to accelerate legacy decommissioning, not every system can or should be immediately replaced. For many carriers, core platforms are tied to complex product configurations, proprietary business logic, or third-party integrations that are costly and risky to unwind.
IT leaders must often advise executive teams that modernization must occur in phases, and that interim cyber hardening of legacy systems is non-negotiable. This includes:
- Segmenting legacy systems on the network to minimize lateral movement
- Wrapping systems with API gateways or reverse proxies that enforce modern access controls
- Logging and monitoring access at the interface layer
- Using data masking, tokenization, or field-level encryption to protect sensitive records
- Training business units on secure workarounds or manual controls during hybrid operations
Managing Tradeoffs: Business Agility vs. Cyber Risk
Security leaders in P&C insurance must often be the voice of risk amid enthusiasm for transformation. While business units push for faster modernization, the security team must assess the tradeoffs between velocity and vulnerability.
One of the most difficult decisions is determining which systems can tolerate risk and for how long. For example, does a legacy claims intake system need to be hardened if it’s read-only and behind multiple layers of access control? Or is it better to focus effort on a legacy rating engine that will soon be exposed through APIs to third-party vendors? These conversations require deep alignment between teams, framing cyber risk not as a blocker, but as a partner in resilience.
A Strategic Approach to Secure Modernization
To navigate the legacy core trap effectively, leading P&C insurers are adopting a few key strategies:
- Modernization Playbooks: Creating repeatable frameworks that outline the security, compliance, and technical steps for phasing out legacy systems.
- Zero Trust Implementation: Applying zero trust principles at the identity, network, and application layer, even for systems not originally designed to support them.
- Cross-Functional Governance: Embedding cybersecurity into every stage of the modernization roadmap, from vendor selection to post-deployment testing.
Ultimately, security can’t wait for modernization to be complete. It must evolve alongside it.
It’s Time to Turn Your Legacy System from a Liability to a Fortress
Legacy core systems may be a reality for many insurers, but they don’t have to be a liability. With the right strategy, IT leaders can help their organizations modernize at the right pace while hardening against evolving threats. The key is treating legacy system security not as a sunk cost or technical debt, but as a strategic enabler of transformation.
In the digital insurance economy, modernization without cybersecurity isn’t progress, it’s exposure. And exposure is a risk few insurers can afford.