SFuzz

Implementation(Source code) of paper: SFuzz: Slice-based Fuzzing for Real-Time Operating Systems

Overview of SFuzz

Static Analysis

Perform taint analysis on the specified firmware, slice and patch the program for the taint analysis results.

This part uses the firmware collection in the evaluation_set folder as input.

Instructions for running this tool

1. Download Ghidra (we use version 9.2.3).
2. Change MAXMEM=2G to MAXMEM=4G in the analyzeHeadless file in the support directory of Ghidra folder.
3. sudo apt install openjdk-11-jdk
4. Place each file in a specific directory according to run.sh or modify run.sh according to the file location.
5. Run run.sh for a single firmware or run run_all.py for the entire firmware set.

Directories

├── README.md
├── evaluation_set   #  Unpacked firmware collection
├── findtrace_output #  Static analysis results for firmware in evaluation_set
├── findtrace.py     #  Ghidra script that performs taint analysis and outputs slices and patches
├── run.sh           #  Shell scripts for processing individual firmware
├── run_all.py       #  Python script for batch processing of multiple firmware
└── setbase.py       #  Ghidra script for setting the base address for firmware loading

Run

For processing individual firmware

Be sure to modify run.sh according to the actual file location before you run it

sudo ./run.sh firmware_path  arch  base_addr

example:

sudo ./run.sh evaluation_set/DIR-100/30_DIR100 MIPS:BE:32:default 0x80000100

For batch processing of multiple firmware

sudo python3 run_all.py

Output

Most of the files end with an underscore and a number, which represents the number of the call tree corresponding to the current file.

30_DIR100_result/
├── call_checksum_0  # Address of checksum function calls
├── .......
├── call_checksum_7
├── calltrace_0      # Results of call trace in call tree
├── ........
├── calltrace_7
├── cbranch_info_0   # Jumping information at the branch
├── ........
├── cbranch_info_7
├── dict_0           # String information on the call tree (used to add to the AFL dictionary)
├── ........
├── dict_7
├── exec_0           # Contextual information used for fuzzing (source address and sink address, etc.)
├── ........
├── exec_7
├── patch_0          # Patch results for function calls or branches
├── ........
├── patch_7
├── sink_buf_0       # Information about the sink function address and its corresponding buffer
├── ........
├── sink_buf_7
├── stack_retaddr_0  # Return address information on the stack
├── ........
├── stack_retaddr_7
├── summary          # Statistical Information
├── summary.json
├── xalloc_0         # Cross-reference information for the alloc function
├── ........
└── xalloc_7

Dynamic Analysis

Dynamic analysis includes fuzzing and concolic solving.

This project relies on the output of the static analysis as input.

Running environment configuration

Ubuntu:16.04

pushd ~
sudo apt install -y libc6-armel-cross gcc-arm-linux-gnueabi
sudo apt install -y libc6-mipsel-cross gcc-mipsel-linux-gnu
sudo apt install -y python3-pip git wget python automake python-setuptools # required by afl-unicorn
sudo apt install -y clang-6.0
sudo ln -s `which clang-6.0` /usr/bin/clang
sudo pip3 install --upgrade "pip<21.0.0"
sudo pip3 install pwntools
git clone https://github.com/Battelle/afl-unicorn
pushd ~/afl-unicorn
make
sudo make install
cd unicorn_mode
sudo ./build_unicorn_support.sh
popd 
popd 

Also, AFL requires: if in a docker environment, execute with root privileges outside the docker environment, otherwise execute the following statements directly with root privileges.

echo core > /proc/sys/kernel/core_pattern

There are also minor modifications to the dependent projects.

https://amusing-aluminum-be0.notion.site/d0de68137f884c1984d4ae7c762b566f

To get the docker image directly, go to: https://drive.google.com/file/d/1tNDaHhYV_K5ys3M9VoBI_l6oj004too_/view?usp=sharing where the code needs to be updated with a git pull

build fuzz loader

make or make "UFDBG=-DUF_DEBUG -g"

run

in ./dynamic_analysis dir:

(in tmux session)
python3 ./hybrid_all.py <device findtrace output dir>  <device firmware path>

example:

python3 ./hybrid_all.py ~/findtrace_output/2834_AC11_result ~/evaluation_set/Tenda_AC11/2834_AC11