On premise user enumeration - Metasploit


This page contains detailed information about how to use the auxiliary/scanner/msmail/onprem_enum metasploit module. For list of all metasploit modules, visit the Metasploit Module Library.

Table Of Contents
hide

Module Overview

Name: On premise user enumeration
Module: auxiliary/scanner/msmail/onprem_enum
Source code: modules/auxiliary/scanner/msmail/onprem_enum.go
Disclosure date: 2018-11-06
Last modification time: 2018-12-07 13:29:56 +0000
Supported architecture(s): -
Supported platform(s): -
Target service / protocol: -
Target network port(s): -
List of CVEs: -

On premise enumeration of valid exchange users

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

This module is a scanner module, and is capable of testing against multiple hosts.

msf > use auxiliary/scanner/msmail/onprem_enum
msf auxiliary(onprem_enum) > show options
    ... show and set options ...
msf auxiliary(onprem_enum) > set RHOSTS ip-range
msf auxiliary(onprem_enum) > exploit

Other examples of setting the RHOSTS option:

Example 1:

msf auxiliary(onprem_enum) > set RHOSTS 192.168.1.3-192.168.1.200

Example 2:

msf auxiliary(onprem_enum) > set RHOSTS 192.168.1.1/24

Example 3:

msf auxiliary(onprem_enum) > set RHOSTS file:/tmp/ip_list.txt

Required Options

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

Knowledge Base

OWA (Outlook Webapp) is vulnerable to time-based user enumeration attacks. This module leverages all known, and even some lesser-known services exposed by default Exchange installations to enumerate users. It also targets Office 365 for error-based user enumeration.

  • Error-based user enumeration for on premise Exchange services

Note: Currently uses RHOSTS which resolves to an IP which is NOT desired, this is currently being fixed

Verification Steps

  • Start msfconsole
  • use auxiliary/scanner/msmail/onprem_enum
  • set RHOSTS <target>
  • set (USERorUSER_FILE`)
  • run
  • creds

Results should look something like below if valid users were found:

host      origin    service        public  private  realm  private_type
----      ------    -------        ------  -------  -----  ------------
10.1.1.1  10.1.1.1  443/tcp (owa)
10.1.1.1  10.1.1.1  443/tcp (owa)  chris

Go back to menu.

Msfconsole Usage

Here is how the scanner/msmail/onprem_enum auxiliary module looks in the msfconsole:

msf6 > use auxiliary/scanner/msmail/onprem_enum

msf6 auxiliary(scanner/msmail/onprem_enum) > show info

       Name: On premise user enumeration
     Module: auxiliary/scanner/msmail/onprem_enum
    License: Metasploit Framework License (BSD)
       Rank: Normal
  Disclosed: 2018-11-06

Provided by:
  poptart
  jlarose
  Vincent Yiu
  grimhacker
  Nate Power
  Nick Powers
  clee-r7

Check supported:
  No

Basic options:
  Name       Current Setting  Required  Description
  ----       ---------------  --------  -----------
  RHOSTS                      yes       The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
  THREADS    1                yes       The number of concurrent threads (max one per host)
  USERNAME                    no        Single user name to do identity test against
  USER_FILE                   no        Path to file containing list of users

Description:
  On premise enumeration of valid exchange users

Module Options

This is a complete list of options available in the scanner/msmail/onprem_enum auxiliary module:

msf6 auxiliary(scanner/msmail/onprem_enum) > show options

Module options (auxiliary/scanner/msmail/onprem_enum):

   Name       Current Setting  Required  Description
   ----       ---------------  --------  -----------
   RHOSTS                      yes       The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
   THREADS    1                yes       The number of concurrent threads (max one per host)
   USERNAME                    no        Single user name to do identity test against
   USER_FILE                   no        Path to file containing list of users

Advanced Options

Here is a complete list of advanced options supported by the scanner/msmail/onprem_enum auxiliary module:

msf6 auxiliary(scanner/msmail/onprem_enum) > show advanced

Module advanced options (auxiliary/scanner/msmail/onprem_enum):

   Name                 Current Setting  Required  Description
   ----                 ---------------  --------  -----------
   ShowProgress         true             yes       Display progress messages during a scan
   ShowProgressPercent  10               yes       The interval in percent that progress should be shown
   VERBOSE              false            no        Enable detailed status messages
   WORKSPACE                             no        Specify the workspace for this module

Auxiliary Actions

This is a list of all auxiliary actions that the scanner/msmail/onprem_enum module can do:

msf6 auxiliary(scanner/msmail/onprem_enum) > show actions

Auxiliary actions:

   Name  Description
   ----  -----------

Evasion Options

Here is the full list of possible evasion options supported by the scanner/msmail/onprem_enum auxiliary module in order to evade defenses (e.g. Antivirus, EDR, Firewall, NIDS etc.):

msf6 auxiliary(scanner/msmail/onprem_enum) > show evasion

Module evasion options:

   Name  Current Setting  Required  Description
   ----  ---------------  --------  -----------

Go back to menu.

Error Messages

This module may fail with the following error messages:

Error Messages

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.

Unable to parse 'Threads' value using default (5)

Here is a relevant code snippet related to the "Unable to parse 'Threads' value using default (5)" error message:

34:		userFile := params["USER_FILE"].(string)
35:		userName := params["USERNAME"].(string)
36:		host := params["rhost"].(string)
37:		threads, e := strconv.Atoi(params["THREADS"].(string))
38:		if e != nil {
39:			module.LogError("Unable to parse 'Threads' value using default (5)")
40:			threads = 5
41:		}
42:	
43:		if threads > 100 {
44:			module.LogInfo("Threads value too large, setting max(100)")

Expected 'USER_FILE' or 'USERNAME' field to be populated

Here is a relevant code snippet related to the "Expected 'USER_FILE' or 'USERNAME' field to be populated" error message:

44:			module.LogInfo("Threads value too large, setting max(100)")
45:			threads = 100
46:		}
47:	
48:		if userFile == "" && userName == "" {
49:			module.LogError("Expected 'USER_FILE' or 'USERNAME' field to be populated")
50:			return
51:		}
52:	
53:		var validUsers []string
54:		avgResponse := basicAuthAvgTime(host)

Unable to resolve host provided to determine valid users.

Here is a relevant code snippet related to the "Unable to resolve host provided to determine valid users." error message:

81:		} else if msmail.WebRequestCodeResponse(url2) == 401 {
82:			urlToHarvest = url2
83:		} else if msmail.WebRequestCodeResponse(url3) == 401 {
84:			urlToHarvest = url3
85:		} else {
86:			module.LogInfo("Unable to resolve host provided to determine valid users.")
87:			return []string{}
88:		}
89:		var validusers []string
90:		tr := &http.Transport{
91:			TLSClientConfig: &tls.Config{InsecureSkipVerify: true},

Unable to resolve host provided to determine valid users.

Here is a relevant code snippet related to the "Unable to resolve host provided to determine valid users." error message:

129:		} else if msmail.WebRequestCodeResponse(url2) == 401 {
130:			urlToHarvest = url2
131:		} else if msmail.WebRequestCodeResponse(url3) == 401 {
132:			urlToHarvest = url3
133:		} else {
134:			module.LogInfo("Unable to resolve host provided to determine valid users.")
135:			return -1
136:		}
137:	
138:		//We are determining sample auth response time for invalid users, the password used is irrelevant.
139:		pass := "Summer201823904"

Error determining whether length of times gathered is even or odd to obtain median value.

Here is a relevant code snippet related to the "Error determining whether length of times gathered is even or odd to obtain median value." error message:

167:			medianTime = (sliceOfTimes[positionTwo] + sliceOfTimes[positionOne]) / 2
168:		} else if len(sliceOfTimes)%2 != 0 {
169:			position := len(sliceOfTimes)/2 - 1
170:			medianTime = sliceOfTimes[position]
171:		} else {
172:			module.LogError("Error determining whether length of times gathered is even or odd to obtain median value.")
173:		}
174:		module.LogInfo("Avg Response: " + time.Duration(medianTime).String())
175:		return time.Duration(medianTime)
176:	}
177:

Go back to menu.

Go back to menu.

See Also

Check also the following modules related to this module:

Authors

  • poptart
  • jlarose
  • Vincent Yiu
  • grimhacker
  • Nate Power
  • Nick Powers
  • clee-r7

Version

This page has been produced using Metasploit Framework version 6.1.36-dev. For more modules, visit the Metasploit Module Library.

Go back to menu.