TL;DR: GEF
is a kick-ass set commands for X86, ARM, MIPS, etc. to
make GDB cool again for exploit dev.
GEF
is aimed to be used mostly by exploiters and reverse-engineers. It
provides additional features to GDB using the Python API to assist during the
process of dynamic analysis or exploit development.
GEF
fully relies on GDB API and other Linux specific source of information
(such as /proc/pid
). As a consequence, some of the features might not work on
custom or harden systems such as GrSec.
It has fully support for Python2 and Python3 indifferently (as more and more
distro start pushing gdb
compiled with Python3 support).
Simply make sure you're having a GDB 7.x .
$ wget -q -O- https://github.com/hugsy/gef/raw/master/gef.sh | sh
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
And
local:~ $ gdb -q
gef> gef-remote your.ip.address:1234
There are none: GEF
works out of the box! However, to enjoy all the coolest features, it is highly recommended to install:
capstone
(by Nguyen Anh Quynh)is an alternative disassembly engine, and keystone
is an (arguably the best) assembly engine.
You can use pip
to simply and quickly install it.
$ pip2 install capstone keystone # for Python2.x
$ pip3 install capstone keystone # for Python3.x
capstone
provides an alternative to the gdb
disassembler, which could be useful specifically when dealing with complex/uncommon instructions.
keystone
allows 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).
Install is simple through the released packages but I would recommend instead to rely on the GIT master branch.
$ 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.
ROPgadget
(written by Jonathan Salwan) is simply the best cross-platform ROP gadget finder. It has been totally integrated inside gef
to benefit of all of its awesomeness.
$ pip[23] install ropgadget
Simply run this
$ pip install ropgadget capstone keystone
Yes ! Why not ?! PEDA is a fantastic tool to
do the same, but is only to be used for x86-32 or x86-64. On the other hand,
GEF
supports all the architecture supported by GDB
(x86, ARM, MIPS, PowerPC,
SPARC, and so on).
Go here