DrAFL : Fuzzing Binaries With No Source Code On Linux

Original AFL supports black-box coverage-guided fuzzing using QEMU mode. I highly recommend to try it first and if it doesn’t work you can try drAFL tool.


You need to specify DRRUN_PATH to point to drrun launcher and LIBCOV_PATH to point to libbinafl.so coverage library. You also need to switch off AFL’s fork server (AFL_NO_FORKSRV=1) and probably AFL_SKIP_BIN_CHECK=1. See step 5 in the build section below for more details.

NOTE: Don’t forget that you should use 64-bit DynamoRIO for 64-bit binaries and 32-bit DynamoRIO for 32-bit binaries, otherwise it will not work. To make sure that your target is running under DynamoRIO, you can run it using the following command:

drrun – – <path/to/your/app/> <app_args>

Instrumentation DLL

Instrumentation library is a modified version of winAFL’s coverage library created by Ivan Fratric.

Also Read – Easysploit : Metasploit Automation Easier & Faster Than Ever


Step 1. Clone drAFL repo

git clone https://github.com/mxmssh/drAFL.git /home/max/drAFL
cd /home/max/drAFL

Step 2. Clone and build DynamoRIO

git clone https://github.com/DynamoRIO/dynamorio
mkdir build_dr
cd build_dr/
cmake ../dynamorio/
make -j
cd ..

If you have any problems with DynamoRIO compilation check this page

Step 3. Build coverage tool

mkdir build
cd build
cmake ../bin_cov/ -DDynamoRIO_DIR=../build_dr/cmake
make -j
cd ..

Step 4. Build patched AFL

cd afl/
cd ..

Step 5. Configure environment variables and run the target

cd build
mkdir in
mkdir out
echo “AAAA” > in/seed
export DRRUN_PATH=/home/max/drAFL/build_dr/bin64/drrun
export LIBCOV_PATH=/home/max/drAFL/build/libbinafl.so
../afl/afl-fuzz -m none -i in -o out — ./afl_test @@

In case of afl_test you should expect 25-30 exec/sec and 1 unique crash in 2-3 minutes.