Millions of Windows and Linux-based devices could be hit by what researchers call Thunderspy attacks, where flaws in Thunderport interfaces are exploited in a matter of minutes.

Initially discovered by a student at the Eindhoven University of Technology in the Netherlands, the attacks can be accomplished with minimal gear from threat actors. This includes some portable hardware and a screwdriver, although attackers would need physical access to a Thunderport-equipped machine as well.

Developed by Apple and Intel, Thunderport was intended to let people use a single connector for video and charging peripherals. The Thunderspy attacks exploit what the researcher describes as flaws in the technology’s underlying security protocols.

Inside a Thunderspy Attack

In a proof of concept that was captured on video, the researcher used a commonly available Serial Peripheral Interface (SPI) programmer device that exchanges data between microcontrollers and other hardware.

After attaching the SPI programmer to an SOP8 clip on the bottom of a laptop with a Thunderbolt port, the researcher was able to turn off device settings designed to protect its data from third parties by rewriting the firmware. This meant he was able to log in without a password to the laptop in less than five minutes, with equipment that only cost about $400.

While many cyberattacks involve some kind of phishing campaign to fool users into clicking on a malicious link, Thunderspy happens without leaving a visible trace afterward, the researcher said. It can also work whether or not a company admin has used strong passwords, full disk encryption or even if the device has been locked by the user.

This is not the first time Thunderbolt has raised IT security concerns. Last year, a researcher published findings about another vulnerability, dubbed Thunderclap, which took advantage of the technology’s direct memory access (DMA).

How to Prevent a Thunderspy Exploit

Intel responded to the Thunderspy research in a blog post that suggested its DMA protection would mitigate much of the risk. Other preventive measures include disabling the BIOS connection to Thunderbolt ports.

This may be yet another reason to consider a unified endpoint management (UEM) solution to ensure you’re covered for all potential security threats and not simply traditional malware.