CowboyRobot writes: "Columbia University grad student Ang Cui demonstrated how networked printers and phones can be abused by attackers. "The attack I demonstrated is caused by the multiple vulnerabilities within the syscall interface of the CNU [Cisco Native Unix] kernel," Cui tells Dark Reading. "It is caused by the lack of input validation at the syscall interface, which allows arbitrary modification of kernel memory from userland, as well as arbitrary code execution within the kernel. This, in turn, allows the attacker to become root, gain control over the DSP [Digital Signal Processor], buttons, and LEDs on the phone. The attack I demonstrated patches the existing kernel and DSP in order to carry out stealthy mic exfiltration.""