[Bandit-OverTheWire] Level 21 -> Level 22

두비니

·

2020. 9. 24. 16:12

 

 

 

Bandit Level 21 → Level 22

Level Goal

A program is running automatically at regular intervals from cron, the time-based job scheduler. Look in /etc/cron.d/ for the configuration and see what command is being executed.

Commands you may need to solve this level

cron, crontab, crontab(5) (use “man 5 crontab” to access this)

 

접속

접속 : ssh bandit21@bandit.labs.overthewire.org -p2220
pw : gE269g2h3mw3pwgrj0Ha9Uoqen1c9DGr

 

cron이라는걸로 실행하고있는데 /etc/cron.d/를 보라고 하네요. 봅시다

 

bandit21@bandit:~$ cd /etc/cron.d
bandit21@bandit:/etc/cron.d$ ls
cronjob_bandit15_root  cronjob_bandit22  cronjob_bandit24
cronjob_bandit17_root  cronjob_bandit23  cronjob_bandit25_root

 

일단 bandit22를 봅시다

 

bandit21@bandit:/etc/cron.d$ cat cronjob_bandit22
@reboot bandit22 /usr/bin/cronjob_bandit22.sh &> /dev/null
* * * * * bandit22 /usr/bin/cronjob_bandit22.sh &> /dev/null

 

뭔진모르겠다만 저기 알려주는거봐서 들어가봅시다

 

bandit21@bandit:~$ cd /usr/bin/cronjob_bandit22.sh
-bash: cd: /usr/bin/cronjob_bandit22.sh: Not a directory
bandit21@bandit:~$ cat /usr/bin/cronjob_bandit22.sh
#!/bin/bash
chmod 644 /tmp/t7O6lds9S0RqQh9aMcz6ShpAoZKF7fgv
cat /etc/bandit_pass/bandit22 > /tmp/t7O6lds9S0RqQh9aMcz6ShpAoZKF7fgv

 

오 bandit22 내용을 저 tmp파일에 넣어놨네요

 

bandit21@bandit:~$ cat /tmp/t7O6lds9S0RqQh9aMcz6ShpAoZKF7fgv
Yk7owGAcWjwMVRwrTesJEwB7WVOiILLI