DVFSspy: Using Dynamic Voltage and Frequency Scaling as a Covert Channel for Multiple Procedures
Pengfei Qiu, Dongsheng Wang, Yongqiang Lyu, Gang Qu · 2022 27th Asia and South Pacific Design Automation Conference (ASP-DAC) · 2022
Dynamic Voltage and Frequency Scaling (DVFS) is a widely deployed low-power technology in modern systems. In this paper, we discover a vulnerability in the implementation of the DVFS technology that allows us to measure the processor's frequency in the userspace. By exploiting this vulnerability, we successfully implement a covert channel on the commercial Intel platform and demonstrate that the covert channel can reach a throughput of 28.41bps with an error rate of 0.53%. This work indicates that the processor's hardware information that is unintentionally leaked to the userspace by the privileged kernel modules may cause security risks.