Jonas Juffinger (Graz University of Technology), Fabian Rauscher (Graz University of Technology), Giuseppe La Manna (Amazon), Daniel Gruss (Graz University of Technology)

Covert channels and side channels bypass architectural security boundaries. Numerous works have studied covert channels and side channels in software and hardware. Thus, research on covert-channel and side-channel mitigations relies on the discovery of leaky hardware and software components.

In this paper, we perform the first study of timing channels inside modern commodity off-the-shelf SSDs. We systematically analyze the behavior of NVMe PCIe SSDs with concurrent workloads. We observe that exceeding the maximum I/O operations of the SSD leads to significant latency spikes. We narrow down the number of I/O operations required to still induce latency spikes on 12 different SSDs. Our results show that a victim process needs to read at least 8 to 128 blocks to be still detectable by an attacker. Based on these experiments, we show that an attacker can build a covert channel, where the sender encodes secret bits into read accesses to unrelated blocks, inaccessible to the receiver. We demonstrate that this covert channel works across different systems and different SSDs, even from processes running inside a virtual machine. Our unprivileged SSD covert channel achieves a true capacity of up to 1503 bit/s while it works across virtual machines (cross-VM) and is agnostic to operating system versions, as well as other hardware characteristics such as CPU or DRAM. Given the coarse granularity of the SSD timing channel, we evaluate it as a side channel in an open-world website fingerprinting attack over the top 100 websites. We achieve an F1 score of up to 97.0. This shows that the leakage goes beyond covert communication and can leak highly sensitive information from victim users. Finally, we discuss the root cause of the SSD timing channel and how it can be mitigated.

View More Papers

Understanding reCAPTCHAv2 via a Large-Scale Live User Study

Andrew Searles (University of California Irvine), Renascence Tarafder Prapty (University of California Irvine), Gene Tsudik (University of California Irvine)

Read More

QMSan: Efficiently Detecting Uninitialized Memory Errors During Fuzzing

Matteo Marini (Sapienza University of Rome), Daniele Cono D'Elia (Sapienza University of Rome), Mathias Payer (EPFL), Leonardo Querzoni (Sapienza University of Rome)

Read More

The Skeleton Keys: A Large Scale Analysis of Credential...

Yizhe Shi (Fudan University), Zhemin Yang (Fudan University), Kangwei Zhong (Fudan University), Guangliang Yang (Fudan University), Yifan Yang (Fudan University), Xiaohan Zhang (Fudan University), Min Yang (Fudan University)

Read More

Crosstalk-induced Side Channel Threats in Multi-Tenant NISQ Computers

Ruixuan Li (Choudhury), Chaithanya Naik Mude (University of Wisconsin-Madison), Sanjay Das (The University of Texas at Dallas), Preetham Chandra Tikkireddi (University of Wisconsin-Madison), Swamit Tannu (University of Wisconsin, Madison), Kanad Basu (University of Texas at Dallas)

Read More