A researcher and PhD student at Columbia University recently added VoIP phones to the list of pressing concerns. Ang Cui demonstrated an attack against a Cisco-branded phone where he was able to put code on the phone. Cui said the circuit board attack could easily and quickly be done by someone with physical access. He added that the compromise of one phone would put an organization s network at risk. Cisco said the issue was patched in November (Bug ID: CSCuc83860)
Source: https://threatpost.com/cisco-voip-phone-hacked-turned-listening-device-121712/77324/