Mobile applications, Internet of Things devices and web services are pervasive and they all encrypt the communications between servers and clients to not have information leakages. While the network traffic is encrypted, packet sizes and timings are still visible to an eavesdropper and these properties can leak information and sacrifice user privacy. We present TSA, a black box network side-channel analysis tool which detects and quantifies side-channel information leakages. TSA provides the users with the means to automate trace gathering by providing a framework in which the users can write mutators for the inputs to the system under analysis. TSA can also take as input traces directly for analysis if the user prefers to gather them separately. TSA is open-source and available as a Python package and a command-line tool. TSA demo, tool and benchmarks are available at https://github.com/kadron/tsa-tool.

Browsers use security policies to block malicious behaviors. Cross-Origin Read Blocking (CORB) is a browser security policy for preventing side-channel attacks such as Spectre. We propose a web browser security policy fuzzer called CorbFuzz for checking CORB and similar policies. In implementing a security policy, the browser only has access to HTTP requests and responses, and takes policy actions based solely on those interactions. In checking the browser security policies, CorbFuzz uses a policy oracle that tracks the web application behavior and infers the desired policy action based on the web application state. By comparing the policy oracle with the browser behavior, CorbFuzz detects weaknesses in browser security policies. CorbFuzz checks the web browser policy by fuzzing a set of web applications where the state-related queries are symbolically evaluated for increased coverage and automation. CorbFuzz collects type information from database queries and branch conditions in order to prevent the generation of inconsistent data values during fuzzing. We evaluated CorbFuzz on CORB implementations of Chromium and Webkit, and Opaque Response Blocking (ORB) policy implementation of Firefox using web applications collected from GitHub. We found three classes of weaknesses in Chromium’s implementation of CORB.

Information leakage in software systems is a problem of growing importance. Networked applications can leak sensitive information even when they use encryption. For example, some characteristics of network packets, such as their size, timing and direction, are visible even for encrypted traffic. Patterns in these characteristics can be leveraged as side channels to extract information about secret values accessed by the application. In this paper, we present a new tool called AutoFeed for detecting and quantifying information leakage due to side channels in networked software applications. AutoFeed profiles the target system and automatically explores the input space, explores the space of output features that may leak information, quantifies the information leakage, and identifies the top-leaking features. Given a set of input mutators and a small number of initial inputs provided by the user, AutoFeed iteratively mutates inputs and periodically updates its leakage estimations to identify the features that leak the greatest amount of information about the secret of interest. AutoFeed uses a feedback loop for incremental profiling, and a stopping criterion that terminates the analysis when the leakage estimation for the top-leaking features converges. AutoFeed also automatically assigns weights to mutators in order to focus the search of the input space on exploring dimensions that are relevant to the leakage quantification. Our experimental evaluation on the benchmarks shows that AutoFeed is effective in detecting and quantifying information leaks in networked applications.

Deep Neural Networks (DNN) are increasingly used in a variety of applications, many of them with serious safety and security concerns. This paper describes DeepCheck, a new approach for validating DNNs based on core ideas from program analysis, specifically from symbolic execution. DeepCheck implements novel techniques for lightweight symbolic analysis of DNNs and applies them to address two challenging problems in DNN analysis: 1) identification of important input features and 2) leveraging those features to create adversarial inputs. Experimental results with an MNIST image classification network and a sentiment network for textual data show that DeepCheck promises to be a valuable tool for DNN analysis.