“The flaw used the fact that the head-mounted Glass camera scans any photo it takes for a QR code in order to set up Wi-Fi or Bluetooth connections to a smartphone for internet access.
Whenever the Glass software detects a QR code, it decodes it to see if it names a Wi-Fi network to connect to. It will do this even if the code does not occupy the whole of the frame - so a hacker could get a Glass owner to hack their own device just by standing near a printout of special QR code.”

Google Glass hacked with malicious QR code to yield its pictures and video