Many people don’t realize that printers can be a security risk. However, printers are computers that store data and connect to networks, making them an attractive target for hackers. In this article, I’ll explain how hackers can exploit printers and what you can do to secure your devices.
What Makes Printers Vulnerable to Attacks?
Printers have several vulnerabilities that hackers can take advantage of:
Outdated Firmware
Most printers run outdated firmware that contains known security flaws. Hackers can exploit these vulnerabilities to gain access to the printer and network. Firmware updates are not always automatic or easy to perform for the average user. Outdated firmware is one of the biggest printer security risks.
Open Ports
Printers have open ports to allow printing from many devices. Hackers can use these ports to send malicious commands and code to the printer. Common printer ports like TCP 9100, TCP 631, and TCP 515 are frequently targeted.
Unsecured Web Interfaces
Many printers have web interfaces for configuration and management. These web apps often have default passwords or security flaws that give hackers a way in. Once in the web interface, a hacker has full control of the device.
Weak Network Security
Printers are rarely separated from the main network with things like firewalls or network segmentation. They often have direct access to sensitive systems. This makes exploiting printers an easy backdoor into the larger network.
Plaintext Communication
Print jobs are typically transmitted in unencrypted plaintext. A hacker able to intercept this traffic can easily read sensitive documents and communications.
Weak Access Controls
Printers often have weak authentication methods like default passwords or unprotected configuration panels. Combined with poor physical security, an attacker can easily access the printer to exploit it directly.
How Hackers Can Exploit Printers
Once a hacker has access to a printer, either remotely or physically, there are many types of exploits they can perform:
Intercepting Print Jobs
Hackers can monitor and intercept print jobs to steal sensitive documents, including things like tax records, financial data, medical records, and proprietary information.
Manipulating or Altering Documents
By intercepting print jobs, hackers can strategically change or replace text in documents to spread disinformation or commit fraud.
Installing Malware
Malware can be installed on printer firmware that spreads across the network and spies on all communications and activity. Printers make an ideal place to hide malware that is hard to detect.
Stealing Data
Printers store sensitive information like scan images, fax data, printer usage history, network credentials, and address book contacts. Hackers can steal all this data.
Spreading Malware
Printers can be used to spread malware to any users that connect to them. Infecting a heavily used printer gives widespread access to attack many victims.
Launching Denial of Service Attacks
By overwhelming the printer with print jobs and exploiting firmware flaws, hackers can trigger DoS attacks to take down printers and disrupt productivity.
Using the Printer as an Attack Platform
Once compromised, printers can be used as a platform to pivot attacks deeper into the network against other devices and servers.
Physically Damaging the Device
In extreme cases, hackers can manipulate printers to physically damage themselves by overheating them or forcing mechanical components to operate out of specifications.
How To Secure Your Printers
Here are key steps you should take to reduce printer security risks:
Update Firmware Frequently
Apply firmware updates from the manufacturer as soon as available to patch known vulnerabilities. Sign up for alerts about new updates.
Change Default Passwords
Remove generic default passwords and use strong unique credentials for admin accounts and WiFi access.
Enable Strong Authentication
Require two-factor or multifactor authentication to access printer web interfaces and functions when available.
Segment Your Network
Put printers on their own VLAN or network segment separated by a firewall from other assets. Limit communication to only essential systems.
Use a VPN
Encrypt print jobs being transmitted over networks by setting up a VPN on the printer or print server.
Disable Unneeded Protocols and Services
Only enable printing protocols and network services needed for essential functions. Disable anything not in use like Telnet, FTP, IPSec, SNMP, etc.
Restrict Physical Access
Put printers in secure rooms and lock the panels to prevent unauthorized changes.
Monitor Printer Traffic
Use tools like intrusion detection systems to monitor printer network traffic and alert on anomalies.
Keeping printers secure takes some extra effort but is vital to protect your networks and data from being compromised through these overlooked devices. Following security best practices can help safeguard your printers against many types of attacks. Be proactive in finding and patching firmware vulnerabilities before hackers can exploit them.
