TYS 0x04 - Is it really that easy?!

• 2019-05-16 19:02
• TYS  
• permission  
• privilege escalation  
• docker  

This post is part of the Test Your Skills series. You can find an introduction here. And an overview of all TYS’s currently available is over here.

Challenge

Your objective? Get root! But, do it without making any changes to the container/image or the file-system outside your users home directory (/home/void) and do not change the docker run command (run it the way shown below)!

root@hacked:~ # docker load -i tys_0x04_void.tar.bz2
Loaded image: void:latest
root@hacked:~ # docker run -it void
~ $ id
uid=31337(void) gid=31337(void)
~ $ pwd
/home/void

Download the tys_0x04_void.tar.bz2 and get crackin!

Have fun hunting, feel free to post your approach / write-up and let me know if you have any questions, feedback or general comments in the respective twitter thread over here:
https://twitter.com/mytty_project/status/1129080008478269440

Verify the files you download with:

md5sum     fd28c14e4df3173eab348ae99363ea42                                  cdn/tys/tys_0x04_void.tar.bz2
sha1sum    c9fa3c2bb3c0816485bf07faa8f4b78921c4a451                          cdn/tys/tys_0x04_void.tar.bz2
sha256sum  979d0668c3494da944bd9347512bde5823ec3b4f00c303015851e8e3b43251c5  cdn/tys/tys_0x04_void.tar.bz2