FBCTF Bases

fbctf-bases.txt

### DEBIAN STRETCH ###

PART I: python script
Become root.
1. $ sudo -i
Make fbctf directory in /opt
2. # cd /opt
3. # mkdir fbctf
Get my modified score_base.py script
4. # wget https://gist.githubusercontent.com/Bryan1998/772cf58e6aff7cf360387886f5af56ff/raw/0eae6687df97af7c8246ff468f142730c8375c3c/score_base.py
Add python script to cron
5. # crontab -e
  a. add this to the bottom: @reboot python /opt/fbctf/score_base.py
  b. save and exit
  c. reboot machine: # reboot NOW

PART II: chroot environment
Create user "johnny"
MAKE SURE YOU ARE ROOT!
1. # adduser johnny
  a. enter password and press enter for all the fields
Kick off user "Johnny" after 2 minutes
2. crontab -e
  a. add this to the bottom: */2 * * * * killall -u johnny -HUP
  b. save and exit
Now for the actual chroot.
Add links to devices
3.
  a. # mkdir -p /home/johnny/dev/		
  b. # cd /home/johnny/dev/
  c. # mknod -m 666 null c 1 3
  d. # mknod -m 666 tty c 5 0
  e. # mknod -m 666 zero c 1 5
  f. # mknod -m 666 random c 1 8
4.
  a. # chown root:root /home/johnny
  b. # chmod 0755 /home/johnny
  c. # ls -ld /home/johnny
5.
  a. # mkdir -p /home/johnny/bin
  b. # cp -v /bin/bash /home/johnny/bin/
  c. # cp -v /bin/cat /home/johnny/bin/
  d. # cp -v /bin/ls /home/johnny/bin/
6.
  a. # mkdir -p /home/johnny/lib/x86_64-linux-gnu
  b. # cp /lib/x86_64-linux-gnu/(libc.so.6,libdl.so.2,libncursesw.so.5,libpcre.so.3,libpthread.so.0,libselinux.so.1,libtinfo.so.5,libz.so.1) /home/johnny/lib/x86_64-linux-gnu/
7.
  a. # mkdir -p /home/johnny/lib64
  b. # cp /lib64/ld-linux-x86-64.so.2 /home/johnny/lib64
8.
  a. # touch /home/johnny/.score_points
  b.
9.
  a. # cd /home/johnny/
  b. # wget https://gist.githubusercontent.com/Bryan1998/117c0d6688bc4bd90a246927035677b6/raw/857ce5aba7187ecd774ffaf62e51181b45de4fb8/hint.sh
  c. # chmod a+x hint.sh
PART III: Configuring SSH for chroot
1.
  a. # nano /etc/ssh/sshd_config
  b. add this to the bottom:
  --START--
    Match User tecmint
    ChrootDirectory /home/test
  --END--
  c. save and exit
2. 
  a. # systemctl restart sshd
 
PART IV: THE END!!
AWESOME!  You just did a FBCTF base.

When adding a base, save it, then edit it and add a link, such as: 10.183.3.3:12345
Now for it to ACTUALLY work you need to turn off the game and turn it back on.
MAKE SURE THE BASE IS RUNNING BEFORE YOU TURN THE GAME BACK ON!!