The SpeechInput feature in Blink, as used in Google Chrome before 35.0.1916.114, allows remote attackers to enable microphone access and obtain speech-recognition text without indication via an INPUT element with a -x-webkit-speech attribute.
https://src.chromium.org/viewvc/blink?revision=171373&view=revision
http://www.securityfocus.com/bid/67582
http://secunia.com/advisories/60372
http://googlechromereleases.blogspot.com/2014/05/stable-channel-update_20.html