A group of researchers at ANSSI, a French government security agency, discovered that hackers can use radio waves to trigger voice commands on any Android phone or iPhone that has Google Now or Siri active with a microphone or pair of headphones plugged in, allowing them to silently control Siri from as far as 16 feet away, according to Wired. The hack takes advantage of the microphone or headphones by using them as an antenna for the electrical signals they use to control Siri.

"The possibility of inducing parasitic signals on the audio front-end of voice-command-capable devices could raise critical security impacts," the researchers said in the study.

The researchers reached out to Apple and Google and urged them to create better security for headphones due to the potential of electromagnetic waves to be used for malicious purposes, according to ABC News.

"The sky is the limit here," said Vincent Strubel of ANSSI. "Everything you can do through the voice interface, you can do remotely and discreetly through electromagnetic waves."

Despite these vulnerabilities, users can protect themselves from the Siri hack by always keeping headphones unplugged and disabling voice control when not using either of these features, according to CBS News.