Modern office copiers and multifunction printers (MFPs) are fully networked computers. They run operating systems, store documents on internal hard drives, connect to cloud services, and communicate with email servers. Yet most businesses exclude them from cybersecurity planning entirely — a gap that attackers have learned to exploit with increasing frequency.
This article covers what those risks are, why they matter, which industries face the greatest exposure, and what concrete steps reduce them.
Copiers and printers are cybersecurity risks because they are network-connected devices that run software, store data, and accept inbound connections — yet most organizations treat them as office equipment rather than IT assets. That classification gap means they are rarely patched, rarely audited, and rarely included in incident response plans. Attackers know this and target printers specifically because of it.
Between July 2021 and April 2022, cybercriminals conducted approximately 65,000 attacks through the Windows Print Spooler application alone. Security researchers also disclosed the "Printer Shellz" vulnerability set, which affected at least 150 models of HP multifunction printers and exposed them to remote code execution — meaning an attacker could run malicious code on the device from across a network without physical access.
A core reason printers remain vulnerable: only 36% of enterprises promptly apply firmware updates to their printers, according to data cited by TechRadar. The remaining 64% leave known exploits unpatched for weeks, months, or indefinitely.
Most modern multifunction printers store document data on internal hard drives or flash storage during and after normal operation. A document scanned, printed, faxed, or copied passes through the device's memory and may be written to that internal storage.
Depending on device configuration, that stored data can include:
When a copier is returned at the end of a lease, resold, or disposed of without a verified hard drive wipe, that stored data goes with it. A business that leased a copier for four years may have thousands of documents sitting on a drive that is shipped to a reseller or refurbisher without any security review.
The most common printer security vulnerabilities fall into five categories: unpatched firmware, default credentials, unsecured network ports, unencrypted data transmission, and physical document exposure.
Printer manufacturers release firmware updates to address known security flaws. Because printers are not managed the same way as servers or workstations, these updates frequently go uninstalled. A printer running firmware from two or three years ago may contain publicly documented vulnerabilities that any attacker can find in published exploit databases.
Most printers ship with default administrator usernames and passwords — often something as simple as "admin/admin" or "admin/1234." A significant number of deployed business printers never have these credentials changed. Anyone with network access can log into the device's web-based admin panel and reconfigure it, extract stored documents, or use it as a pivot point into the broader network.
Printers communicate over multiple network protocols, including FTP, Telnet, SNMP, and raw TCP ports. Many of these are enabled by default and are either unencrypted or use outdated security standards. An attacker on the same network segment — or who has gained any level of network access — can intercept print traffic or interact directly with the device through these open ports.
When a user sends a document to a printer, that data travels across the network as a print job. If the connection is not encrypted, anyone monitoring network traffic can capture the document in transit. This is particularly relevant in environments with guest Wi-Fi networks or shared wireless access points that are not properly segmented.
Printed documents left uncollected in an output tray are a simple but real data risk. In shared office environments, documents containing financial data, employee information, or client records sit visible and accessible until someone retrieves them. This applies equally to fax output that arrives without a recipient present to collect it.
An unsecured printer can lead to a data breach through three primary pathways: network infiltration, data extraction from stored documents, and credential theft.
Network infiltration occurs when an attacker uses the printer as an entry point to move laterally across the network. Because printers have ongoing connections to file servers, email systems, and cloud storage, a compromised printer gives an attacker a foothold inside the network perimeter without triggering the alerts that a direct server attack might generate.
Data extraction happens when an attacker accesses the printer's internal storage — either remotely through an unsecured admin panel or physically when a device is retired — and recovers documents that were never purged.
Credential theft occurs when cached network credentials stored on the printer (for cloud integration, email relay, or Active Directory authentication) are retrieved and used to authenticate into other systems.
The combination of these pathways means a single unsecured printer can expose not just its own stored documents but also provide access to the systems that printer was connected to.
Industries that handle regulated or sensitive data face the highest risk from printer security vulnerabilities. However, the exposure is not limited to large enterprises — 57% of SMBs consider printer security a low priority, even though 56% have experienced print-related data loss in the past year, according to research cited by TechRadar.
Industries with elevated exposure include:
Small businesses in any of these categories carry the same regulatory obligations as larger organizations but typically have fewer controls in place.
Securing printers requires treating them as managed network devices with the same controls applied to servers and workstations. The following steps address the primary vulnerability categories.
Every printer and copier should have its default administrator password changed during initial setup. The new password should follow the same complexity standards applied to other network devices — minimum length, mixed character types, and no reuse of passwords used elsewhere on the network
Printer firmware updates should be scheduled and tracked the same way operating system patches are managed. A quarterly firmware review at minimum is a reasonable baseline. Organizations that manage multiple devices should use print management software or fleet management tools that allow centralized firmware deployment.
Printers should be configured to run only the protocols required for their function. FTP, Telnet, and SNMP v1 and v2 should be disabled unless specifically needed. Where SNMP is required, use SNMP v3 with authentication. Close raw print ports if they are not in use.
Configure printers to use TLS/SSL for all network communications. Most enterprise-grade MFPs support encrypted connections for print jobs, scan-to-email, and admin panel access. Verify that these settings are active and test them periodically.
Most business-class copiers and MFPs have a setting that automatically overwrites stored document data after each job. This setting is typically disabled by default. Enable it to prevent document accumulation on the device's internal storage.
Pull printing requires a user to authenticate at the printer — by entering a PIN, tapping an access card, or using a mobile credential — before a document is released. This eliminates the physical exposure risk of uncollected output and creates a log of who printed what and when.
Placing printers on a dedicated VLAN, isolated from general user traffic and critical server infrastructure, limits the damage a compromised printer can cause. Even if an attacker gains access to the printer, network segmentation prevents lateral movement to other systems.
Before any copier leaves your environment — at the end of a lease, during a hardware refresh, or when disposing of equipment — verify that the internal hard drive has been securely wiped or physically destroyed. Request a certificate of destruction from the service provider when applicable.
Employee behavior creates a significant portion of printer-related security risk. Training should address three practical areas: secure print habits, recognizing misconfigurations, and reporting procedures.
Secure print habits include collecting printed documents promptly, not leaving sensitive materials in output trays, using pull printing when available, and avoiding printing sensitive documents on shared or guest-accessible devices.
Recognizing misconfigurations means employees who manage or regularly use printers should know what a default login screen looks like, understand that open admin panels are a problem, and know how to report a device that appears to have been accessed or reconfigured.
Reporting procedures should be clear and low-friction. If an employee notices a printer behaving unusually — sending unexpected faxes, displaying unfamiliar activity logs, or prompting for credentials it normally does not request — there should be a defined path to report that to IT or a managed services provider without delay.
Printer security is one component of an endpoint security strategy. The same frameworks that govern workstation and server security — asset inventory, patch management, access controls, network segmentation, and incident response — apply directly to printers and copiers.
Businesses that work with a managed IT services provider should verify that printers are explicitly included in their managed device inventory and that patch management, configuration audits, and monitoring cover printing infrastructure alongside other endpoints.
Incident response plans should include printer-specific scenarios: what to do if a printer's admin credentials are found to be default and exposed, how to isolate a potentially compromised device, and how to assess what data may have been stored on a device before it was identified as at risk.
Printers that connect to document management platforms, cloud storage, or email systems should also be reviewed during any broader security assessment of those integrations. A printer with write access to a shared file server is not just a printer — it is another authenticated endpoint with access to business-critical systems.