Post

OverTheWire: Bandit Level 9 → Level 10

OverTheWire - Bandit

Level Goal

The password for the next level is stored in the file data.txt in one of the few human-readable strings, preceded by several ‘=’ characters.

Commands you may need to solve this level

grep, sort, uniq, strings, base64, tr, tar, gzip, bzip2, xxd

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> whatis grep  
grep (1)             - print lines that match patterns

> whatis sort  
sort (1)             - sort lines of text files

> whatis uniq  
uniq (1)             - report or omit repeated lines

> whatis strings  
strings (1)          - print the sequences of printable characters in files

> whatis base64  
base64 (1)           - base64 encode/decode data and print to standard output

> whatis tr  
tr (1)               - translate or delete characters

> whatis tar  
tar (1)              - an archiving utility

> whatis gzip  
gzip (1)             - compress or expand files

> whatis bzip2  
bzip2 (1)            - a block-sorting file compressor, v1.0.8

> whatis xxd  
xxd (1)              - make a hexdump or do the reverse.

Note: All commands don’t have to be used to complete level

Helpful Reading Material

Learn Piping and Redirection - Linux Tutorial

How to Use Grep Command in Linux [12 Useful Examples]

strings - Unix, Linux Command

Solution

View the contents of the current working directory

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bandit9@bandit:~$ ls  
data.txt

Peek at the data that is present in the file. This can be achieved using the head command

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bandit9@bandit:~$ head -n 4 data.txt�L�lω;��ßOܛ��ǤX��NdT$��x7��@D@�o��+D��B��M֢�Z/,_��w��#�5���
                                                              Ў�e�&�-��Ϣ�6Q8��J�%fa�
�np�6l
|c���WW"&8��f��
��VJ�$�S~����d�
                 �p�k�U�;ֿ�v�Am��H��tɘ�3�ߘ�(ǟ�E'
                                                     ���'��:��uP�ע���������g�

(The -n flag allows us to specify how many lines to print from the start of the file. We can use the tail command to look at the last n lines of a file)

Human-readable strings in a file can be found using the strings command. The -e flag is used to specify the character encoding. We are assuming the human-readable line is ASCII text so we use “s” for the encoding type

(Refer to attached resources for more information)

We also know that the line with the password starts with a few “=” characters. We can look for this pattern in the file using the grep command. We can combine all these commands into a single line using the | (pipe) operator

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bandit9@bandit:~$ cat data.txt | strings -e s | grep ==
========== the*2i"4
========== password
Z)========== is
&========== truKLdjsbJ5g7yyJ2X2R0o3a5HQJFuLk

Note: The cat command is used to read the data from the file which is then passed as input to the next command in the line using pipes

We have found the password for the next level !!

Logout of the current session and use the password of user bandit10 to access the next level

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> ssh bandit10@bandit.labs.overthewire.org -p 2220
This is a OverTheWire game server. More information on http://www.overthewire.org/wargames

bandit10@bandit.labs.overthewire.org's password: truKLdjsbJ5g7yyJ2X2R0o3a5HQJFuLk
This post is licensed under CC BY 4.0 by the author.