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Ringzer0CTF – Linux – Level2


Ringzer0CTF – Linux – Level2


Objective:
Get the flag…… I don’t know what else to put here

Find architect password

User: morpheus
Password: VNZDDLq2x9qXCzVdABbR1HOtz
ssh challenges.ringzer0team.com port 10148


Solution:

Ok so we login with the same user/pass of the last level and now need to find another password

So this one took a bit of time for a refresher for me.

First I tried the same process we did for the last level to see if we could find a command running with the password like we did for trinity….
Nope

Ok so Let’s just search the entire files system for “architect”

Lets get to /
Cd ../

morpheus@lxc-sysadmin:/$ ls
backup  bin  boot  dev  etc  home  lib  lib64  media  mnt  nohup.out  opt  proc  root  run  sbin  srv  sys  tmp  usr  var


ok now my first iteration here was just grep -r “architect”

That gave me way to many things….

Ok how do we filter out permission denied lets start there.

We can use 2> /dev/null

This redirects all stderr ( standard error output) to /dev/nul therefor it doesn’t show up for our grep


Ok that did get rid of all the permission denied std error messages but we are still getting way to may results.
The grep command we are using is also hitting on words that contain architect like architecture, which shows up a whole lot in the results

Lets reformat the grep search to only include architect and not anything more than that

Here is the MAN for grep
https://linux.die.net/man/1/grep

I think we might have some luck with -w

-w, --word-regexp
Select only those lines containing matches that form whole words. The test is that the matching substring must either be at the beginning of the line, or preceded by a non-word constituent character. Similarly, it must be either at the end of the line or followed by a non-word constituent character. Word-constituent characters are letters, digits, and the underscore.


So this will filter out anything where architect is not the whole word it needs a non-word character either directly before or after archichect

morpheus@lxc-sysadmin:/$ grep -r -w "architect" 2> /dev/null
etc/fstab:#//TheMAtrix/phone  /media/Matrix  cifs  username=architect,password=$(base64 -d "RkxBRy0yMzJmOTliNDE3OGJkYzdmZWY3ZWIxZjBmNzg4MzFmOQ=="),iocharset=utf8,sec=ntlm  0  0
etc/group:challenger:x:1000:morpheus,trinity,architect,oracle,neo,cypher
etc/group:architect:x:1003:
etc/passwd:architect:x:1002:1003::/home/architect:/bin/bash
etc/subgid:architect:231072:65536
etc/subuid:architect:231072:65536
 

Cool looks like we found something

etc/fstab:#//TheMAtrix/phone  /media/Matrix  cifs  username=architect,password=$(base64 -d "RkxBRy0yMzJmOTliNDE3OGJkYzdmZWY3ZWIxZjBmNzg4MzFmOQ=="),iocharset=utf8,sec=ntlm  0  0



looks like this has a user/pass set but the pass is base64 encoded.

Lets flip it out and see what we get

morpheus@lxc-sysadmin:/$ echo 'RkxBRy0yMzJmOTliNDE3OGJkYzdmZWY3ZWIxZjBmNzg4MzFmOQ==' | base64 -d
FLAG-232f99b4178bdc7fef7eb1f0f78831f9
morpheus@lxc-sysadmin:/$


another flag, cool






morpheus@lxc-sysadmin:/$ grep -r "\<architect\>" 2> /dev/null

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