Security expert Chris Roberts tweeted from his seat on a United Airlines plane, jokingly telling followers that he would be able to hack into the plane’s WiFi network. It is thought that a terrorist could theoretically control a plane by hacking into the WiFi network, all from the comfort of their seat, and the FBI are worried, according to the BBC.

FBI Steps In After Airline Hacking Threat

FBI issues warning to airlines

The tweet led to Mr. Roberts being banned from all United Airlines flights, but his joke exposes wider concerns on the issue. Although the FBI and the U.S. Transportation Security Administration (TSA) have said that they have not seen any evidence that navigation systems could be tampered with via the plane’s on-board WiFi, the theory is still being investigated.

FBI officials made a series of recommendations to airlines, asking them to report any suspicious activity involving travelers connecting their own wires to the in-flight entertainment (IFE) system, any evidence of tampering with IFE systems, any social media messages which relate to aviation wireless signals, as well as recommending that they keep a log of any suspicious network activity for analysis.

Mr. Roberts, co-founder of security company One World Labs, was questioned by the FBI when the plane landed, while his laptop and other devices were taken for analysis. Shortly afterwards he was blocked from boarding a flight to California. Roberts has given a series of interviews explaining the vulnerabilities of airline computer systems, and even claimed to be able to view operational data by connecting to a computer under his seat.

A theoretical possibility

Worries over the vulnerability of airplanes first surface a few years ago. Commonly used planes operate a single network for navigation systems and passenger WiFi connections. “The risk is that a hacker sitting in the back of a plane, or even one on the ground, could use the wi-fi connection to hack into the avionics and then remotely fly the plane,” said security expert Bruce Schneier.

Any weaknesses are not yet publicly known, but it is still theoretically possible. However Schneier maintains that “in the scheme of internet risks I worry about, it’s not very high.”

Many airlines now offer WiFi to passengers, and rules regarding the use of smart devices have been relaxed. Now it appears the FBI is worried about an attack due to the increasing availability of WiFi.