Fabian Rauscher (Graz University of Technology), Andreas Kogler (Graz University of Technology), Jonas Juffinger (Graz University of Technology), Daniel Gruss (Graz University of Technology)

Modern processors are equipped with numerous features to regulate energy consumption according to the workload. For this purpose, software brings processor cores into idle states via dedicated instructions such as hlt. Recently, Intel introduced the C0.1 and C0.2 idle states. While idle states previously could only be reached via privileged operations, these new idle states can also be reached by an unprivileged attacker. However, the attack surface these idle states open is still unclear.

In this paper, we present IdleLeak, a novel side-channel attack exploiting the new C0.1 and C0.2 idle states in two distinct ways. Specifically, we exploit the processor idle state C0.2 to monitor system activity and for novel means of data exfiltration, and the idle state C0.1 to monitor system activity on logical sibling cores. IdleLeak still works regardless of where the victim workload is scheduled, i.e., cross-core, due to the low-level x86 design. We demonstrate that IdleLeak leaks significant information in a native keystroke-timing attack, achieving an F1 score of 90.5% and a standard error on the timing prediction of only 12 μs. We also demonstrate website- and video-fingerprinting attacks using IdleLeak traces, pre-processed with short-time Fourier transforms, and classified with convolutional neural networks. These attacks are highly practical with F1 scores of 85.2% (open-world website fingerprinting) and 81.5% (open-world video fingerprinting). We evaluate the throughput of IdleLeak side channels in both directions in covert channel scenarios, i.e., using interrupts and performance-increasing effects. With the performance-increasing effect, IdleLeak achieves a true capacity of 7.1 Mbit/s in a native and 46.3 kbit/s in a cross-VM scenario. With interrupts, IdleLeak achieves 656.37 kbit/s in a native scenario. We conclude that mitigations against IdleLeak are necessary in both personal and cloud environments when running untrusted code.

View More Papers

HistCAN: A real-time CAN IDS with enhanced historical traffic...

Shuguo Zhuo, Nuo Li, Kui Ren (The State Key Laboratory of Blockchain and Data Security, Zhejiang University)

Read More

The Dark Side of E-Commerce: Dropshipping Abuse as a...

Arjun Arunasalam (Purdue University), Andrew Chu (University of Chicago), Muslum Ozgur Ozmen (Purdue University), Habiba Farrukh (University of California, Irvine), Z. Berkay Celik (Purdue University)

Read More

Beyond the Surface: Uncovering the Unprotected Components of Android...

Hao Zhou (The Hong Kong Polytechnic University), Shuohan Wu (The Hong Kong Polytechnic University), Chenxiong Qian (University of Hong Kong), Xiapu Luo (The Hong Kong Polytechnic University), Haipeng Cai (Washington State University), Chao Zhang (Tsinghua University)

Read More

Understanding the Implementation and Security Implications of Protective DNS...

Mingxuan Liu (Zhongguancun Laboratory; Tsinghua University), Yiming Zhang (Tsinghua University), Xiang Li (Tsinghua University), Chaoyi Lu (Tsinghua University), Baojun Liu (Tsinghua University), Haixin Duan (Tsinghua University; Zhongguancun Laboratory), Xiaofeng Zheng (Institute for Network Sciences and Cyberspace, Tsinghua University; QiAnXin Technology Research Institute & Legendsec Information Technology (Beijing) Inc.)

Read More