The cloud computing landscape has evolved sig-nificantly in recent years, embracing various sandboxes to meet the diverse demands of modern cloud applications. These sandboxes encompass container-based technologies like Docker and gVisor, microVM-based solutions like Fire-cracker, and security-centric sandboxes relying on Trusted Execution Environments (TEEs) such as Intel SGX and AMD SEV. However, the practice of placing multiple tenants on shared physical hardware raises security and privacy concerns, most notably side-channel attacks. In this paper, we investigate the possibility of fingerprinting containers through CPU frequency reporting sensors in Intel and AMD CPUs. One key enabler of our attack is that the current CPU frequency information can be accessed by user-space attackers. We demonstrate that Docker images exhibit a unique frequency signature, enabling the distinction of different containers with up to 84.5 % accuracy even when multiple containers are running simultaneously in different cores. Additionally, we assess the effectiveness of our attack when performed against several sandboxes deployed in cloud environments, including Google's gVisor, AWS’ Firecracker, and TEE-based platforms like Gramine (utilizing Intel SGX) and AMD SEV. Our empirical results show that these attacks can also be carried out successfully against all of these sandboxes in less than 40 seconds, with an accuracy of over 70 % in all cases. Finally, we propose a noise injection-based countermeasure to mitigate the proposed attack on cloud environments.

Cache-based website fingerprinting (WF) attacks violate user privacy where the attacker leverages the shared last-level cache in CPUs and analyzes the fingerprints through machine learning and deep learning models. WF attacks are even applicable in Incognito and anonymized browser platforms, leading to a serious threat to the public. Several defense techniques inject random noise during website rendering to degrade the attack success rate, while these techniques either create large performance overhead or cannot obfuscate the WF dataset entirely when the attacker retrains a new learning model with noisy fingerprints.

Microarchitectural attacks have become increasingly threatening the society with diverse set of attacks such as Spectre and Meltdown. Vendor patches cannot keep up with the pace of the new threats, which makes the dynamic anomaly detection tools more evident than before. Unfortunately, hardware performance counters (HPCs) utilized in previous works can detect a few microarchitectural attacks due to the small number of counters that can be profiled concurrently while introducing high performance overhead. These challenges consequently yield to inefficient detection tools in real-world security-critical systems. In this study, we introduce MAD-EN dynamic detection tool that leverages system-wide energy consumption traces collected from a generic Intel RAPL tool to detect ongoing anomalies in two different microarchitectures, namely Intel Comet Lake and Intel Tiger Lake. In the first phase of MAD-EN, we can distinguish 16 variants from 11 different micro-architectural attacks from benign applications by utilizing a binary-class CNN-based model with an F1 score of 0.998, which makes our tool the most generic attack detection tool so far. In the second phase, MAD-EN can recognize the respective attack types with a 95% accuracy by utilizing a multi-class CNN-based classification technique after the anomaly is detected. We demonstrate that MAD-EN introduces 69.3% less performance overhead compared to performance counter-based detection mechanisms, allowing more feasible real-time detection tool for generic purpose systems.

The arm race between hardware security engineers and side-channel researchers has become more competitive with more sophisticated attacks and defenses in the last decade. While modern hardware features improve the system performance significantly, they may create new attack surfaces for malicious people to extract sensitive information about users without physical access to the victim device. Although many previously exploited hardware and OS features were patched by OS developers and chip vendors, any feature that is accessible from userspace applications can be exploited to perform software-based side-channel attacks.