Angora

Angora

Angora is a mutation-based coverage guided fuzzer. The main goal of Angora is to increase branch coverage by solving path constraints without symbolic execution.

Published Work

Arxiv: Angora: Efficient Fuzzing by Principled Search, S&P 2018.

Building Angora

Build Requirements

• Linux-amd64 (Tested on Ubuntu 16.04/18.04 and Debian Buster)
• Rust stable (>= 1.31), can be obtained using rustup
• LLVM 4.0.0 - 12.0.1 : run PREFIX=/path-to-install ./build/install_llvm.sh.

Environment Variables

Append the following entries in the shell configuration file (~/.bashrc, ~/.zshrc).

export PATH=/path-to-clang/bin:$PATH
export LD_LIBRARY_PATH=/path-to-clang/lib:$LD_LIBRARY_PATH

Fuzzer Compilation

The build script will resolve most dependencies and setup the runtime environment.

./build/build.sh

System Configuration

As with AFL, system core dumps must be disabled.

echo core | sudo tee /proc/sys/kernel/core_pattern

Test

Test if Angora is builded successfully.

cd /path-to-angora/tests
./test.sh mini

Running Angora

Build Target Program

Angora compiles the program into two separate binaries, each with their respective instrumentation. Using autoconf programs as an example, here are the steps required.

# Use the instrumenting compilers
CC=/path/to/angora/bin/angora-clang \
CXX=/path/to/angora/bin/angora-clang++ \
LD=/path/to/angora/bin/angora-clang \
PREFIX=/path/to/target/directory \
./configure --disable-shared

# Build with taint tracking support 
USE_TRACK=1 make -j
make install

# Save the compiled target binary into a new directory
# and rename it with .taint postfix, such as uniq.taint

# Build with light instrumentation support
make clean
USE_FAST=1 make -j
make install

# Save the compiled binary into the directory previously
# created and rename it with .fast postfix, such as uniq.fast

If you fail to build by this approach, try wllvm and gllvm described in Build a target program.

Also, we have implemented taint analysis with libdft64 instead of DFSan (Use libdft64 for taint tracking).

Fuzzing

./angora_fuzzer -i input -o output -t path/to/taint/program -- path/to/fast/program [argv]

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For more information, please refer to the documentation under the docs/ directory.

• Angora Overview
• Build a target program
• Running Angora
• Use libdft64 for taint tracking
• Example - Fuzz program file by Angora
• Run Angora on LAVA
• Exploit attack points
• Usage
• Configuration Files
• Environment variables
• UI Terminology
• Troubleshoot
• Related works