Vulnerabilities in Aging Tech and the Collapse Behind the Firewall

The crossover between legacy infrastructure and modern threats now represents one of the most significant risk fronts in cybersecurity, new research from Cisco and advisory firm WPI Strategy shows. 

The routers, switches, and servers that power systems behind the scenes in most offices worldwide were never built for the threat environment of 2025. As generative AI expands what attackers can discover and exploit, those neglected devices become a strategic vulnerability.

This is especially true in the US and UK, which face the highest relative exposure from legacy tech in critical national infrastructure, according to the joint study by Cisco and WPI across five major countries (the United States, United Kingdom, Germany, France, and Japan). Japan emerged ahead of the pack, owing to consistent upgrade regimes, decentralized architecture, and a national emphasis on digital resilience.

What makes aging tech so dangerous today? Four main dynamics have emerged so far.

• Weak Defaults and Obsolete Firmware: Many ageing devices still run on outdated firmware with default settings that were never designed to defend against today's cyber threats. These systems often lack modern update mechanisms, making them easier for attackers to locate and exploit.
• Legacy Tech Bridges Physical and Digital Risk: Legacy hardware often sits at the intersection of IT and operational technology (OT) (anything from control systems to factory floor sensors). A breach can cause far more than data loss: it can stop production, derail logistics, or even disrupt essential public services.
• Threat Evolution Outpaces Refresh Cycles: Threat evolution now outpaces the pace at which companies can refresh infrastructure. AI tools help attackers rapidly scan for outdated systems and exploit known flaws, shifting the cost of doing nothing from invisible to inevitable.
• Unseen Attack Surfaces Lurk Across Networks: Organizations frequently underestimate the scale of the issue. Forgotten routers, unused network switches, and unmonitored storage boxes often linger across environments. Any of these can serve as a backdoor into more sensitive systems if left unpatched.

“Our recent global study indicates that 74% of leaders believe outdated infrastructure is already hindering growth, and a staggering 97% view modernized networks as critical for successfully deploying AI, IoT, and cloud technologies,” a Cisco blog post noted. “This isn't just about preventing breaches; it's about enabling innovation and ensuring the resilience needed for the AI era.”

If legacy tech is the problem, visibility is the foundation of the solution. That begins with comprehensive asset inventories, including OT endpoints, IoT devices, and dormant infrastructure. Devices must be mapped, fingerprinted, and monitored continuously. Segmentation, separating high-risk legacy systems from mission-critical infrastructure, limits the fallout from any breach. Behavioral monitoring should flag any device operating outside of established norms, not with signatures or rules, but with pattern-based intelligence. These tools act like tripwires for compromise.

The longer old equipment lingers, the more the cost of doing nothing compounds, not just in exposure, but in potential disruption. Leaders must elevate legacy risk from the IT backlog to the board-level strategy. When companies treat legacy infrastructure as a backlog item, they ignore how modern attackers treat it as a front-line opportunity. 

The solution: visibility, strategy, and governance aligned with a threat environment that evolves in real time.