skysider/pwndocker repository overview

⁠Pwndocker

A docker environment for pwn in ctf based on phusion/baseimage:master-amd64, which is a modified ubuntu 20.04 baseimage for docker

⁠Usage

docker run -d \
	--rm \
	-h ${ctf_name} \
	--name ${ctf_name} \
	-v $(pwd)/${ctf_name}:/ctf/work \
	-p 23946:23946 \
	--cap-add=SYS_PTRACE \
	skysider/pwndocker

docker exec -it ${ctf_name} /bin/bash

⁠included software

• pwntools⁠ —— CTF framework and exploit development library
• pwndbg⁠ —— a GDB plug-in that makes debugging with GDB suck less, with a focus on features needed by low-level software developers, hardware hackers, reverse-engineers and exploit developers
• pwngdb⁠ —— gdb for pwn
• ROPgadget⁠ —— facilitate ROP exploitation tool
• roputils⁠ —— A Return-oriented Programming toolkit
• one_gadget⁠ —— A searching one-gadget of execve('/bin/sh', NULL, NULL) tool for amd64 and i386
• angr⁠ —— A platform-agnostic binary analysis framework
• radare2⁠ —— A rewrite from scratch of radare in order to provide a set of libraries and tools to work with binary files
• seccomp-tools⁠ —— Provide powerful tools for seccomp analysis
• linux_server[64] —— IDA 7.0 debug server for linux
• tmux⁠ —— a terminal multiplexer
• ltrace⁠ —— trace library function call
• strace⁠ —— trace system call

⁠included glibc

Default compiled glibc path is /glibc.

• 2.19 —— ubuntu 12.04 default libc version
• 2.23 —— ubuntu 16.04 default libc version
• 2.24 —— introduce vtable check in file struct
• 2.27 —— ubuntu 18.04 default glibc version
• 2.28~2.30 —— latest libc versions
• 2.31 —— ubuntu 20.04 default glibc version(built-in)

⁠Q&A

⁠How to run in custom libc version?

cp /glibc/2.27/64/lib/ld-2.27.so /tmp/ld-2.27.so
patchelf --set-interpreter /tmp/ld-2.27.so ./test
LD_PRELOAD=./libc.so.6 ./test

or

from pwn import *
p = process(["/path/to/ld.so", "./test"], env={"LD_PRELOAD":"/path/to/libc.so.6"})

⁠How to run in custom libc version with other lib?

if you want to run binary with glibc version 2.28:

root@pwn:/ctf/work# ldd /bin/ls
linux-vdso.so.1 (0x00007ffe065d3000)
libselinux.so.1 => /lib/x86_64-linux-gnu/libselinux.so.1 (0x00007f004089e000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f00406ac000)
libpcre2-8.so.0 => /lib/x86_64-linux-gnu/libpcre2-8.so.0 (0x00007f004061c000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f0040616000)
/lib64/ld-linux-x86-64.so.2 (0x00007f00408f8000)

root@pwn:/ctf/work# /glibc/2.28/64/ld-2.28.so /bin/ls
/bin/ls: error while loading shared libraries: libselinux.so.1: cannot open shared object file: No such file or directory

You can copy /lib/x86_64-linux-gnu/libselinux.so.1 and /lib/x86_64-linux-gnu/libpcre2-8.so.0 to /glibc/2.28/64/lib/, and sometimes it fails because the built-in libselinux.so.1 requires higher version libc:

root@pwn:/ctf/work# /glibc/2.28/64/ld-2.28.so /bin/ls
/bin/ls: /glibc/2.28/64/lib/libc.so.6: version `GLIBC_2.30' not found (required by /glibc/2.28/64/lib/libselinux.so.1)

it can be solved by copying libselinux.so.1 from ubuntu 18.04 which glibc version is 2.27 to /glibc/2.28/64/lib:

docker run -itd --name u18 ubuntu:18.04 /bin/bash
docker cp -L u18:/lib/x86_64-linux-gnu/libselinux.so.1 .
docker cp -L u18:/lib/x86_64-linux-gnu/libpcre2-8.so.0 .
docker cp libselinux.so.1 pwn:/glibc/2.28/64/lib/
docker cp libpcre2-8.so.0 pwn:/glibc/2.28/64/lib/

And now it succeeds:

root@pwn:/ctf/work# /glibc/2.28/64/ld-2.28.so /bin/ls -l /

⁠ChangeLog

⁠2020-09-06

update base image to 20.04(glibc 2.31) and add glibc 2.27

⁠2020-05-22

update radare2 to version 4.4.0 and add r2pipe python binding

⁠2020-04-11

add libc 2.30 and 2.31

⁠2020-02-19

python packages switched to python3 version, remove roputils.py