GEF is a kick-ass set of commands for X86, ARM, MIPS, PowerPC and SPARC to make GDB cool again for exploit dev. It is aimed to be used mostly by exploiters and reverse-engineers, to provide additional features to GDB using the Python API to assist during the process of dynamic analysis and exploit development.

It has full support for both Python2 and Python3 indifferently (as more and more distros start pushing gdb compiled with Python3 support).

Some of GEF features include:

• One single GDB script.
• Entirely OS Agnostic, NO dependencies: GEF is battery-included and is installable in 2 seconds (unlike PwnDBG).
• Fast limiting the number of dependencies and optimizing code to make the commands as fast as possible (unlike PwnDBG).
• Provides more than 50 commands to drastically change your experience in GDB.
• Easily extendable to create other commands by providing more comprehensible layout to GDB Python API.
• Works consistently on both Python2 and Python3.
• Built around an architecture abstraction layer, so all commands work in any GDB-supported architecture such as x86-32/64, ARMv5/6/7, AARCH64, SPARC, MIPS, PowerPC, etc. (unlike PEDA)
• Suited for real-life apps debugging, exploit development, just as much as CTF (unlike PEDA or PwnDBG)

Simply make sure you have GDB 7.x .

# via the install script
$ wget -q -O- https://github.com/hugsy/gef/raw/master/gef.sh | sh

# manually
$ wget -O ~/.gdbinit-gef.py -q https://github.com/hugsy/gef/raw/master/gef.py
$ echo source ~/.gdbinit-gef.py >> ~/.gdbinit

Then just start playing (for local files):

$ gdb -q /path/to/my/bin
gef➤  gef help

Or (for remote debugging):

remote:~ $ gdbserver 0.0.0.0:1234 /path/to/file
Running as PID: 666

And:

local:~ $ gdb -q
gef➤  gef-remote -t your.ip.address:1234 -p 666

If your host/VM is connected to the Internet, you can update gef easily to the latest version (even without git installed). with python /path/to/gef.py --update

For example:

$ python ~/.gdbinit-gef.py --update
Updated

If no updates are available, gef will respond No update instead.

This shows a few examples of new features available to you when installing GEF, with the supported architecture.

There are none: GEF works out of the box! However, to enjoy all the coolest features, it is highly recommended to install:

• capstone
• keystone: requires cmake
• unicorn
• Ropper
• RetDec

GEF greatly enhances the capabilities of GDB thanks to a full integration of the following libraries:

• capstone (by Nguyen Anh Quynh) is an alternative disassembly engine, and keystone is an (arguably the best) assembly engine.
• keystone allows us to generate opcodes, which can, for example, then be used as part of a shellcode.

• unicorn (also written by Nguyen Anh Quynh) is a lightweight Qemu-based framework to emulate any architecture currently supported by GDB (and even some more).

For a quick installation, use the pip packaged version:

$ pip2 install capstone unicorn keystone-engine  # for Python2.x
$ pip3 install capstone unicorn keystone-engine  # for Python3.x

You can use pip to simply and quickly install it.

capstone and keystone are under very active development and improvement, so it is recommended to compile and install them from git.

$ git clone https://github.com/keystone-engine/keystone.git
$ mkdir -p keystone/build && cd keystone/build
$ ../make-share.sh
$ sudo make install
$ sudo ldconfig
$ cd ../bindings/python && sudo ./setup.py build && sudo ./setup.py install

capstone provides an alternative to the gdb disassembler, which could be useful specifically when dealing with complex/uncommon instructions.

Install is simple through pip, but to get the latest features from it, installation from the repository is recommended:

$ git clone https://github.com/unicorn-engine/unicorn.git && cd unicorn && ./make.sh && sudo ./make.sh install

unicorn integration in gef allows to emulate the behaviour to specific instructions (or block of instructions) based on the runtime context, without actually running it, and therefore sparing the trouble of saving the context/running the new context/restoring the old context. Additionally, gef can generate a standalone unicorn Python script, if you want/need to reproduce steps outside the debugger.

Ropper (written by Sascha Schirra) is a gadget finder based on ROPgadget. It supports opening multiple files and provides an awesome search option to find accurate gadgets.

$ pip[23] install ropper

Some of the optional dependencies can be installed using Python package installer, pip. Simply run this

$ pip[23] install ropper capstone

Yes! Why not?! PEDA is a fantastic tool to do the same, but only works for x86-32 or x86-64x whereas GEF supports all the architecture supported by GDB (currently x86, ARM, AARCH64, MIPS, PowerPC, SPARC) but is designed to integrate new architectures very easily as well!

To discuss gef, gdb, exploitation or other topics, feel free to join the ##gef channel on the Freenode IRC network. You can also to me (hugsy) via the channel. For those who do not have an IRC client (like weechat or irssi), simply click here.

For bugs or feature requests, just go here and provide a thorough description if you want help.

Side Note: GEF fully relies on GDB API and other Linux-specific sources of information (such as /proc/<pid>). As a consequence, some of the features might not work on custom or hardened systems such as GrSec.

gef was created and maintained by myself, @_hugsy_, but kept fresh thanks to all the contributors.

Or if you just like the tool, feel free to drop a simple "thanks" on IRC, Twitter or other, it is always very appreciated.

I love Open-Source, and just like my other projects I've decided to offer a 🍺 4 🐛 (a.k.a beer4bugs) bounty for GEF, to thank everybody who helps keeping the project living and always better.

The rule is simple, provide a (substantial) contribution to GEF, such as:

1. Submitting a Pull-Request for a new feature/command.
2. Submitting a Pull-Request for a new architecture support.
3. Or sending a relevant issue request (like a bug, crash, or else).

Poke me on the IRC ##gef channel about it, and next time we meet in person (like at a conference), I'll be happy to pay you a beer.

I do also accept beers if you think that the tool is cool! 😉

Cheers 🍻