OverTheWire Wargames

Bandit Level 22 –> Level 23

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.

NOTE: Looking at shell scripts written by other people is a very useful skill. The script for this level is intentionally made easy to read. If you are having problems understanding what it does, try executing it to see the debug information it prints.

Commands you may need to solve this level

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

Solution

change dir to /etc/cron.d then see its content

bandit22@bandit:~$ cd  /etc/cron.d/ 
bandit22@bandit:/etc/cron.d$ ls
cronjob_bandit15_root  cronjob_bandit22  cronjob_bandit24
cronjob_bandit17_root  cronjob_bandit23  cronjob_bandit25_root

Open cronjob_bandit23 to see the command

bandit22@bandit:/etc/cron.d$ cat /usr/bin/cronjob_bandit23.sh 
#!/bin/bash

myname=$(whoami)
mytarget=$(echo I am user $myname | md5sum | cut -d ' ' -f 1)

echo "Copying passwordfile /etc/bandit_pass/$myname to /tmp/$mytarget"

cat /etc/bandit_pass/$myname > /tmp/$mytarget

level pass copy to file in tmp directory its adress obtained from md5sum command

bandit22@bandit:/etc/cron.d$ echo I am user bandit23 | md5sum | cut -d ' ' -f 1
8ca319486bfbbc3663ea0fbe81326349
bandit22@bandit:/etc/cron.d$ cat /tmp/8ca319486bfbbc3663ea0fbe81326349
jc1udXuA1tiHqjIsL8yaapX5XIAI6i0n

Password

jc1udXuA1tiHqjIsL8yaapX5XIAI6i0n

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