Athena: Analyzing and Quantifying Side Channels of Transport Layer Protocols

Recent research has shown a growing number of side-channel vulnerabilities in transport layer protocols, such as TCP and UDP. Those side channels can be exploited by adversaries to launch nefarious attacks. In this paper, we present Athena, an automated tool for detecting, quantifying and explaining side-channel vulnerabilities in vanilla implementations of transport layer protocols. Unlike prior tools, Athena adopts a novel graph-based analysis, making it scalable enough to be the first side-channel analysis tool that can comprehensively analyze the TCP and UDP implementations in several operating systems with significantly higher coverage than the state-of-the-art. Moreover, Athena uses an entropy-based algorithm to identify the most important vulnerabilities. Evaluation on several benchmarks including Linux, FreeBSD, OpenBSD and two open-source IPv4 implementations suggests that Athena can narrow down critical side channels to a single digit (among over 1000 candidates) with a low false positive rate. Besides covering known side channels, Athena also discovers 30 new potential attack surfaces.