symrepl

symrepl is a small utility that helps you investigate the type information inside binaries. It uses lldb in order to access the symbolic information inside a binary.

The main use case of this little helper tool is to help vulnerability researchers find interesting things to use while exploiting software.

Example

The following example shows the loading of the XUL binary and how symrepl can be used to inspect the internals of the types used inside the binary.

Caveats

The script works only on macOS and Linux. On macOS, XCode is required. On Linux, lldb and llvm-config are required.

Installation

# Install `pip` if not installed.
$ easy_install pip

# Install `virtualenv` if not installed.
$ pip install virtualenv

# Create a virtual python environment.
$ virtualenv venv_symrepl

# Activate the environment (POSIX system).
$ source ./venv_symrepl/bin/activate

# Install `symrepl` into the virtual environment.
$ python setup.py install

Dependencies

All the python requirements will be installed automatically using python's setuptools.

• XCode
• python
• pip
• virtualenv (optional)

Usage

Execute symrepl with -h to get help:

$ symrepl -h
usage: symrepl.py [-h] [-f FILENAME]

Symbol REPL.

optional arguments:
  -h, --help            show this help message and exit
  -f FILENAME, --file FILENAME
                        Path to the file with symbols.