FuzzBuilder: Automated building greybox fuzzing environment for C/C++ library

Authors - Joonun Jang (Samsung Research), Huy Kang Kim (Korea University)

Conference - ACSAC 2019 (https://www.acsac.org)

  • 1. Introduction

FuzzBuilder is a tool for generating an executable automatically for library fuzzing by using a unit test. Further, FuzzBuilder can generate seed files to fuzz a specific library API function by analyzing a unit test. Generated executables are compatible with various greybox fuzzers like AFL. Using these features, FuzzBuilder can help to apply greybox fuzzing widely on a development process. We will provide source code of FuzzBuilder with detailed information about how to build and how to use. Briefly, FuzzBuilder requires LLVM-6.0, clang-6.0(exactly 6.0.1) packages to be built. FuzzBuilder has been tested on the Linux Debian 4.9.0-8-amd64. Further, the current version of FuzzBuilder can take only 32-bit bitcode files. It is difficult to set up the same experiment environment of this paper. Thus, we will prepare Dockerfile that can generate a docker image to set up every resource for evaluation automatically. Along with Dockerfile, several bash or python scripts will be provided to getting result from a docker container.

  • 2. Paper abstract

Fuzzing is an effective method to find bugs in software. Many security communities are interested in fuzzing as an automated approach to verify software security because most of the bugs discovered by fuzzing are related to security vulnerabilities. However, not all software can be tested by fuzzing because fuzzing requires a running environment, especially an executable. Notably, in the case of libraries, most of the libraries do not have a relevant executable in practice. Thus, state-of-the-art fuzzers have a limitation to test an arbitrary library.

To overcome this problem, we propose FuzzBuilder to provide an automated fuzzing environment for libraries. FuzzBuilder generates an executable that calls library API functions to enable library fuzzing. Moreover, any executable generated by FuzzBuilder is compatible with existing fuzzers such as AFL. We evaluate the overall performance of FuzzBuilder by testing open source libraries. Consequently, we discovered unknown bugs in libraries while achieving high code coverage. We believe that FuzzBuilder helps security researchers to save both setup cost and learning cost for library fuzzing.

See also: https://github.com/hksecurity/FuzzBuilder