The Dept. of Homeland Security urged computer users recently to disable a common networking technology feature, after researchers warned that hackers could exploit flaws to gain access to tens of millions of vulnerable devices.

The U.S. government’s Computer Emergency Readiness Team, on its website, advised consumers and businesses to disable a feature known as Universal Plug and Play or UPnP, and some other related features that make devices from computers to printers accessible over the open internet.

UPnP, a communications protocol, is designed to let networks identify and communicate with equipment, reducing the amount of work it takes to set up networks.