Attackers don’t always need to find a way in. Sometimes a trusted network hands them one.
A printer or camera on the internal network is granted environmental trust, allowing it to initiate east-west traffic, reach internal services, and communicate freely because nothing in the architecture distinguishes it from a managed asset. That trust is not identity-based. No one evaluated the device. It inherited access from its network position. That assumption is where the attack path begins.
Forgotten devices don’t pose a risk because they’re sophisticated targets. They create risk by operating within trusted environments while remaining entirely outside security processes. Attackers don’t need to defeat the perimeter when they can move through a device that’s already past it and already invisible.
This is a different problem from misconfigured gear or hidden vulnerabilities in active systems. The issue is that entire device classes are never assigned to anyone, never patched, and never reviewed because they don’t register as IT problems in the first place.
Devices that are easily forgotten and why they stay that way
- Printers and multifunction copiers are treated as office utilities, not networked computers. They have internal storage, operating systems, access to file shares, and cached credentials. They hold invoices, contracts, payroll data, and patient records, and they’re patched by no one, because no one owns them as IT assets.
- Security cameras are claimed by physical security teams, so IT never takes ownership. But camera systems are fully networked endpoints with web interfaces, factory credentials, cloud transmission paths, and connections to internal storage. The video feed works, so attention moves elsewhere. The management interface stays exposed.
- Badge readers and access control systems exist in the gap between facilities and IT. They connect to management servers, user directories, and identity systems, often on the same network as business applications, while being owned by a team with no patching process. Default settings stay in place, software goes unreviewed, and the systems remain poorly segmented from everything they have no reason to reach.
- Smart TVs, conference room systems, and digital signage arrive through convenience and stay through inertia. Someone connects a display to Wi-Fi, signs into a few services, and moves on. These are internet-connected computers with wireless radios and management interfaces. They’re never registered, never governed, and never reviewed.
- Old laptops, tablets, and loaner devices are held in reserve for contractors, onboarding delays, and temporary projects. They feel dormant. They may still hold cached credentials, saved VPN profiles, and unpatched software. When activated, they connect as trusted corporate hardware without any of the controls that status implies.
- Personal devices and one-off exceptions typically enter through informal channels, such as a contractor connecting for a short engagement or an employee accessing a portal on a personal machine. They are not onboarded, registered, or monitored. The exception becomes a habit, and the habit becomes a permanent blind spot.
- Smart building systems, including thermostats, sensors, lighting controls, and environmental monitors, support facility operations and offer little IT visibility. They tap into network paths inside weakly segmented environments. Because the building runs normally, no one investigates what those devices can reach.
- Legacy servers and aging appliances persist because removing them feels riskier than leaving them in place. They still support some dependency nobody fully understands, such as a camera archive, a badge system, or an old integration. As they age out of vendor support, known vulnerabilities accumulate and go unpatched. Attackers don’t need zero-days when old flaws stay open indefinitely.
How attackers use forgotten devices
In most real incidents, forgotten devices are not the entry point for attackers. They are where attackers stay. Initial access typically arrives through phishing, stolen credentials, or vulnerabilities in internet-facing systems. What forgotten devices provide is the next stage: a stable, unmonitored position inside the network that no one is watching and no one will notice.
Default credentials and exposed management interfaces matter here, but not primarily as entry points. They matter because they make a forgotten device trivially controllable once an attacker reaches it through lateral movement. No brute force required if the credentials are in the vendor manual.
Persistence is where these devices cause the most damage. A compromised printer or camera generates almost no monitoring attention. It can communicate internally, relay traffic, and maintain a foothold for weeks or months without triggering detection. During that time, the attacker can map the environment, identify targets, and wait for the right moment, while the device sits quietly in the asset inventory’s blind spot.
Lateral movement is what turns a low-value foothold into a serious incident. Flat networks and weak segmentation allow an attacker to move from a camera or smart TV into file shares, directory services, and business applications. The entry point becomes irrelevant once internal movement is unrestricted.
Forgotten devices also create a specific problem for incident response. These devices are excluded from logging, DLP, and audit processes not because someone made that decision, but because no one ever included them. When an incident occurs, investigators don’t pull logs from the printer or forensic data from the camera system because there isn’t an expectation to do so. That makes attribution harder, dwell time longer, and the scope of compromise harder to establish.
Every unaccounted device also slows containment. Teams hesitate to isolate segments or sever connections when they do not know what depends on what. That uncertainty, the direct product of poor asset visibility, gives attackers time and takes it away from defenders.
How to close the gaps
- Inventory every connected device and make discovery continuous rather than periodic. Point-in-time scans miss devices that connect between cycles. Printers, cameras, badge readers, conference systems, sensors, legacy appliances, and vendor-managed equipment all need to be included in the asset register and kept up to date. Stale inventory creates the same blind spots as having no inventory at all.
- Assign a named owner to each device, accounting for org boundaries. Ownership fails when a device crosses team lines and nobody claims it. Badge systems owned by facilities, cameras owned by physical security, and vendor-managed appliances owned by neither are the devices that drift. Ownership needs to be explicit, recorded, and tied to specific responsibilities: patching, access review, and end-of-life decisions. Without that, the device is unowned regardless of what the org chart says.
- Segment device classes away from critical systems and audit exceptions. Segmentation fails when exceptions accumulate. An IoT device receives a temporary rule to access a business system; the rule never gets removed, and six months later, the segment is effectively flat. Placing cameras, printers, and building systems in controlled segments with defined, reviewed communication paths limits blast radius — but only if the exceptions are tracked and expired.
- Change default credentials and restrict admin interfaces. Devices ship with factory passwords because manufacturers build at scale, not for security. Leaving them in place means the barrier to access is documented in a publicly available manual. Change credentials on installation, disable unnecessary services, and restrict management interfaces to specific internal addresses.
- Establish a patching process for nontraditional assets. Track firmware versions and monitor vendor support status. If a device can no longer receive security updates, it should not remain connected and trusted because a device that cannot be patched is a fixed, permanent vulnerability. Replace it or isolate it from anything it could damage.
- Control what connects to the network. Network Access Control, device registration, and zero-trust access policies prevent ad hoc exceptions from becoming permanent blind spots. Without these controls, a personal laptop or unregistered contractor device receives the same network trust as a managed asset simply by being physically present, which is exactly the condition on which this problem is built.
- Audit and decommission on a defined schedule. End-of-life must be a process, not an intention. Disconnect, wipe, remove accounts from directory systems, and confirm removal from the network. Devices kept around “just in case” still need to be governed — because an unmanaged device that isn’t actively used is still actively connected.
Most forgotten devices stay forgotten because removing or properly governing them creates short-term disruption — a camera that needs reconfiguring, a legacy appliance that needs a replacement path, a badge system that needs an owner who doesn’t want the responsibility. That friction is real, and it’s why these devices persist across audits, security reviews, and even incidents. It’s also exactly what keeps the attack path open. The trade-off between operational convenience and governance is not neutral: it is a decision to extend network-level trust to devices no one is watching.
Sources
Microsoft, HP, Corporate Technologies Group, Fastech Solutions, Cyber Wardens, Optiv, Shield Services
About NetworkTigers
NetworkTigers is the leader in the secondary market for Grade A, seller-refurbished networking equipment. Founded in January 1996 as Andover Consulting Group, which built and re-architected data centers for Fortune 500 firms, NetworkTigers provides consulting and network equipment to global governmental agencies, Fortune 2000, and healthcare companies. www.networktigers.com.
