Overthewire Bandit Level 17 -> 18

Solution for the Overthewire.org Bandit level 17 -> 18

Level Goal

There are 2 files in the homedirectory: passwords.old and passwords.new. The password for the next level is in passwords.new and is the only line that has been changed between passwords.old and passwords.new

NOTE: if you have solved this level and see ‘Byebye!’ when trying to log into bandit18, this is related to the next level, bandit19

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Walkthrough

Login to the server using the password obtained from the previous level Bandit level 16 -> 17.

username: bandit17

ssh bandit17@bandit.labs.overthewire.org -p 2220

In this level we are given 2 files full of text that look like passwords.
The password we are looking for is in passwords.new and it is the only line that is different to passwords.old file.

Checking how many lines in each file tells us there is 100 lines. Too many to check by hand.

bandit17@bandit:~$ wc -l passwords.new 
100 passwords.new

bandit17@bandit:~$ wc -l passwords.old 
100 passwords.old

Luckily linux has a tool for comparing files line by line.
That tool is diff.

Diff takes 2 inputs and outputs the line numbers and the differences between them.

bandit17@bandit:~$ diff passwords.new passwords.old
42c42
< kfBf3e##########################
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> w0Yfolrc5bwjS4qw5mq1nnQi6mF03bii
bandit17@bandit:~$