A New York man has brought a class-action lawsuit against Hewlett Packard over a vulnerability that opens the device to an attack.

The complaint, filed in the US district court in San Jose, California, contends that HP knew of the vulnerability but failed to disclose its existence to customers. The suit states: “If [the] plaintiff and other members of the class had known about the defect in the software of the HP printers, they would not have purchased their HP printers.”

Researchers at Columbia University in New York last week said they discovered the flaw in HP LaserJet printers that could allow attackers to steal sensitive documents, gain control of corporate networks or even set the affected devices on fire. This is possible as some HP LaserJet printers do not validate the origin of remote firmware updates before applying them, so anyone can reprogram the devices with malicious firmware.

In lab demonstrations, the researchers were even able to use the vulnerability to overheat the printer's fuser – a ink-drying component – to cause paper to turn brown and smoke. In that demonstration, a thermal switch shut the printer down before a fire was started.

However, HP dismissed the notion that the printers could ignite. In a statement, it said: “HP LaserJet printers have a hardware element called a thermal breaker that is designed to prevent the fuser from overheating or causing a fire. It cannot be overcome by a firmware change or this proposed vulnerability.

“The specific vulnerability exists for some HP LaserJet devices if placed on a public internet without a firewall. In a private network, some printers may be vulnerable if a malicious effort is made to modify the firmware of the device by a trusted party on the network. In some Linux or Mac environments, it may be possible for a specially formatted corrupt print job to trigger a firmware upgrade."

An HP spokeswoman said the company could not comment on pending litigation.